Antenna apparatus and information transmitting system

In an information transmitting system for radio-transmitting information between a fixed station and a mobile station moved within a predetermined moving range, an antenna apparatus is provided on the fixed station side. The antenna apparatus includes a large number of unit antennas, each of which functions as an antenna. These unit antennas are mutually connected to each other, and are arranged along the moving range of the mobile station. The information is transmitted/received in a radio transmission mode between the mobile station and the fixed station via an antenna of the fixed station and the antenna apparatus.

BACKGROUND OF THE INVENTION 
The present invention relates to an antenna apparatus and an information 
transmitting system with using this antenna apparatus capable of 
effectively receiving such information as video (picture) information and 
audio (voice) information transmitted under low power or very low power is 
radio (wireless) signal forms from such moving objects as a self-drive 
robot traveled on a rail or a limited range, an automobile, a car to an 
elevator, and a train. 
In general, when video signal is transmitted/received between a moving 
object and a fixed station, a large-scaled antennas are installed on the 
respective units, the video information is transmitted by using 
public-allowed relatively strong electromagnetic waves in a specific 
frequency. For instance, JP-A-63-92104 (publication No. 1) discloses one 
of the conventional plane antenna. That is, only when the moving object 
has passed such a range covered by the signal projected from the plane 
antenna, this moving object may receive the information from the plane 
antenna. 
Another conventional plane antenna is disclosed in "Current Plane Antenna 
Technique" (publication No. 2) issued by SOGO GIJUTSU CENTER K.K. on Mar. 
25, 1991, on pages 18 to 20 and 401 to 408, and further "Radio Engineering 
Handbook" (publication No. 3) issued by Ohm Sha K. K. on Jan. 31, 1962, 
vol. 11, on pages 580 to 581, FIG. 90. 
SUMMARY OF THE INVENTION 
In the above-described publication No. 1, the information could not receive 
from the plane antenna only when the moving object is located at a 
specific position, but also this information could not receive from the 
plane over the moving range of the moving object. 
The publication No. 2 represents in FIGS. 1.9 and 6.29 such a plane antenna 
that a plurality of plane antenna elements are coupled to form this plane 
antenna. These plane antennas are directed to transmit/receive the radio 
information between the antennas and the moving object moved far from the 
antenna, but not directed to transmit/receive the radio information 
between the antennas and the moving object traveled near the antennas. 
Similarly, the plane antenna shown in the publication No. 3 owns the 
similar problems. 
To transmit information between an elevator car and a rail along which this 
elevator car is traveled, electromagnetic couplings are utilized. Since 
power used in the electromagnetic coupling is very low, the elevator is 
located very close (for instance, on the order of ten mm) to the rail 
under a line-shaped coupling. Thus, the application range is limited. 
In the above-described technique for radio-transmitting the information 
with the relatively strong electromagnetic waves by using the large-scaled 
antenna, in the case that the picture (video) information is 
transmitted/received between the child station (will be referred to a 
"mobile station" hereinafter) by the moving object and the fixed station, 
the antenna power at the mobile station is increased so as to obtain the 
picture information with the broad bandwidth under better quality. 
Accordingly, the output power of the transmitter is increased. Also, to 
increase the antenna gain, the antenna apparatus provided on the fixed 
station is, for instance, a parabola antenna and a YAGI antenna, which are 
large-sized antennas. Moreover, there is another drawback that the mobile 
station apparatus and also the antenna of the fixed station are high cost. 
Since the large-scale receiving antenna is required for the fixed station, 
there is a further drawback in installation of such a large-scale 
receiving antenna. When the output power from the transmitter antenna is 
high, there are practical drawbacks such that interference occurs with 
respect to other picture information transmitting systems, and the usable 
frequency is limited. 
There are further practical drawbacks that when the picture information is 
transmitted between the transmitter antenna and the receiver antenna, 
various standing waves and phase shifts are produced due to multipath of 
the transmitted signals, the fading phenomenon occurs, the signal 
disturbances are produced, and the S/N ratio is deteriorated, resulting in 
lowering of image quality. 
Also, it is very difficult to obtain information with constant quality 
while continuously positioning the antenna of the mobile station opposite 
to the antenna of the fixed station, because of directivity of the 
antennas. 
In particular, when the travel direction of the mobile station is directed 
to various directions, the antenna of the mobile station is not always 
positioned opposite to the fixed station, and it is very difficult to 
maintain the picture information transmission under better quality. 
When the electromagnetic waves are receive by a plurality of antenna 
elements on the side of the fixed station, since there are a phase 
difference and an output difference of wave propagations among the 
respective antenna elements, it is practically difficult to continuously 
obtain information higher than a predetermined level while the mobile 
station is traveled. 
An aim of the present invention is to solve the various problems of the 
above-described prior art, and to provide an information transmitting 
system capable of radio-transmitting information between a mobile station 
and a fixed station with using very low power. In the information 
transmitting system, even when various standing waves are produced due to 
multipath of propagated waves, a fading phenomenon, a phase shift, a 
signal disturbance, and deterioration in S/N ratio can be reduced to 
negligible small values, so that deterioration in quality of the 
information to be transmitted can be prevented. 
Another aim of the present invention is to provide an antenna apparatus 
capable of continuously transmitting information having a level higher 
than a preselected level irrelevant to a travel direction of a mobile 
station. 
According to one aspect of the present invention, such an information 
transmitting system is provided which is comprised of a mobile station 
moved within a predetermined moving range; an antenna apparatus including 
a large number of unit antennas which each functions as an antenna, are 
mutually connected to each other, and are arranged along the moving range 
of the mobile station; and a fixed station connected to the antenna 
apparatus, for transmitting/receiving information via the antenna 
apparatus by way of a radio transmission between the mobile station and 
the fixed station. 
As described above, according to the present invention, since a large 
number of unit antennas for constituting the antenna apparatus are 
arranged along the moving range of the mobile station, the fixed station 
can receive the information from the mobile station over the moving range 
of the mobile station. 
As an example, the above-described mobile station includes an antenna for 
radio-transmitting information between the antenna apparatus and the 
mobile station; and a distance between the antenna of the mobile station 
and the antenna apparatus is shorter than, or equal to 5.lambda. (symbol 
".lambda." being a wavelength of an electromagnetic wave used to 
radio-transmit information). 
Since the antenna of the mobile station is positioned close to the antenna 
apparatus of the fixed station, the information having the quality higher 
than a predetermined level can be continuously transmitted under very low 
power between the mobile station and the fixed station. 
Various problems such that various standing waves are produced by multipath 
of transmitted waves, the fading phenomenon occurs, the phase shifts and 
the signal disturbances are produced, and also the S/N ratio is 
deteriorated can be reduced to negligible small values, and deterioration 
in quality of information to be transmitted can be prevented. 
According to another aspect of the present invention, such a bidirectional 
communication information transmitting system is provided which is 
comprised of: a mobile station moved within a predetermined moving range, 
including a first transmitter, a first receiver, and antenna means 
connected to the first transmitter and the first receiver, for 
transmitting/receiving information between a fixed station and the mobile 
station; an antenna apparatus including a large number of unit antennas 
which each functions as an antenna, are mutually connected to each other, 
and are arranged along the moving range of the mobile station; and a fixed 
station connected to the antenna apparatus, for transmitting/receiving 
information via the antenna apparatus by way of a radio transmission 
between the mobile station and the fixed station; wherein: the fixed 
station includes a second receiver for receiving the information from the 
antenna means of the mobile station, and a second transmitter for 
transmitting the information to the mobile station by way of the radio 
transmission. 
In an example, the above-described mobile station includes a picture 
information output apparatus for outputting picture (video) information as 
the information; the mobile station radio-transmits the picture 
information derived from the picture information output apparatus from the 
first transmitter via the antenna unit; and the second receiver of the 
fixed station receives the picture information via the antenna apparatus. 
According to a further aspect of the present invention, an antenna 
apparatus is provided which is comprised of a plurality of antenna unit 
groups, such as first, second, third and forth antenna unit group, for 
instance; each of which is formed by a plurality of unit antenna units; 
wherein each of the unit antenna units is constructed of at least one unit 
antenna, such as one unit antenna or two unit antennas combined, for 
example; the antenna unit groups are arranged at sequential order such as 
shown in FIG. 19, wherein the unit antenna shown in FIG. 19 is illustrated 
as the representative one; the unit antennas belonging the one antenna 
unit groups, such as first and third groups, are so arranged that the 
shapes of electromagnetic waves irradiated from all the unit antennas 
therein are the same; and the unit antennas belonging the other antenna 
unit groups, such as second and forth groups, are so arranged that the 
shapes of electromagnetic waves irradiated therefrom are different from 
one of the unit antennas in the groups such as the first and the third 
groups; and the unit antennas belonging the same groups are commonly 
connected to each other, that is the unit antennas in the first and third 
groups are commonly connected to each other, as well as in the second and 
forth groups. 
It should be understood that a shape of electromagnetic wave radiation 
implies both of a propagation plane and directivity about 
vertical/horizontal polarization of the electromagnetic wave. 
As described above, since the unit antennas having the different shapes of 
wave radiation are alternately arranged, even when the wave receiving 
direction is varied, the polarized plane of the received wave is 
continuously located opposite to directivity of any one of these unit 
antenna groups of the antenna apparatus. Accordingly, the information with 
better quality can be continuously received. 
When such an antenna apparatus is arranged along the travel surface of the 
information transmitting system, even if the mobile station is not 
traveled in parallel to the longitudinal direction of the travel surface, 
the antenna of the mobile station is always positioned opposite to any one 
of these unit antenna group employed in the antenna apparatus. As a 
consequence, the fixed station can continuously receive the information 
with better quality irrelevant to the travel directions of the mobile 
station. 
In the above-described fixed station, it is possible to employ a group 
selecting circuit connected to a plurality of unit antenna unit groups of 
the antenna apparatus, for comparing information outputs with each other 
received from the plurality of unit antenna unit groups of the antenna 
apparatus, transmitted from the transmitter, whereby the group selecting 
circuit selects the information output of the unit antenna unit group 
having the highest reception output; and a receiver for receiving the 
selection output from the group selecting circuit. 
As described above, the large output of the unit antenna unit group is 
selected from the plurality of unit antenna unit groups to be supplied to 
the receiver, so that the fixed station can continuously receive the 
information with other quality. 
Furthermore, according to another aspect of the present invention, such an 
information transmitting system is provided which is comprised of: a 
mobile station moved within a predetermined moving range; an antenna 
apparatus including a large number of unit antennas which each functions 
as an antenna, are mutually connected to each other, and are arranged 
along the moving range of the mobile station; and a fixed station 
connected to the antenna apparatus, for transmitting/receiving information 
via the antenna apparatus by way of a radio transmission between the 
mobile station and the fixed station; the antenna apparatus is provided 
which is comprised of a plurality of antenna unit groups, such as first, 
second, third and forth antenna unit group, for instance; each of which is 
formed by a plurality of unit antenna units; wherein each of the unit 
antenna units is constructed of at least one unit antenna, such as one 
unit antenna or two unit antennas combined, for example; the antenna unit 
groups are arranged at sequential order such as shown in FIG. 19, wherein 
the unit antenna shown in FIG. 19 is illustrated as the representative 
one; the unit antennas belonging the one antenna unit groups, such as 
first and third groups, are so arranged that the shapes of electromagnetic 
waves irradiated from all the unit antennas therein are the same; and the 
unit antennas belonging the other antenna unit groups, such as second and 
forth groups, are so arranged that the shapes of electromagnetic waves 
irradiated therefrom are different from one of the unit antennas in the 
groups such as the first and the third groups; and the unit antennas 
belonging the same groups are commonly connected to each other, that is 
the unit antennas in the first and third groups are commonly connected to 
each other, as well as in the second and forth groups. 
As previously explained, since the electromagnetic wave transmitted from 
the mobile station is received by at least two unit antenna unit groups 
having the different phases, the fixed station can continuously receive 
the information with better quality irrelevant to the travel directions of 
the mobile station. In particular, since the electromagnetic waves 
received by the same antenna groups contain the essentially in-phase 
components as the major components, the reception outputs of this unit 
antenna unit group are added to each other so as to be emphasized. 
Therefore, the information with better quality can be continuously 
received. 
Preferably, the above-described fixed station includes: a group selecting 
circuit connected to a plurality of unit antenna unit groups of said 
antenna apparatus, for comparing information outputs with each other 
received from said plurality of unit antenna unit groups of said antenna 
apparatus, transmitted from said transmitter, whereby said group selecting 
circuit selects the information output of the unit antenna unit group 
having the highest reception output; and a receiver for receiving the 
selection output from said group selecting circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the accompanying drawings, a detailed description will be 
made of an antenna apparatus and an information transmitting system with 
employment of this antenna apparatus, according to an embodiment of the 
present invention. It should be noted that the same reference numerals are 
employed so as to denote the elements having the same functions, and 
explanations thereof are omitted. 
FIG. 1 is a plan view for showing a plane multi-antenna (antenna apparatus) 
employed in an information transmitting system according to an embodiment 
of the present invention. That is, the plane multi-antenna is so 
constructed that a large number of plate-shaped plane unit antenna 
(namely, an antenna element functioning as an independent antenna, for 
instance, a dipole antenna will be referred to a "unit antenna") provided 
on a fixed station are arranged along a travel (moving) range of a moving 
object, and these plane unit antennas are coupled to each other in an 
integral form. A plane unit antenna per se is described in the 
above-described publication (2), i.e., well known in the art. 
It should be understood that a "plane antenna" defined in the present 
invention implies such an antenna that plane elements for constituting 
this antenna are arranged in a plane manner. That is, this plane antenna 
need not be made precisely flat, but may be made slightly curved, or 
waved. 
FIG. 2 is a side view for illustrating a positional relationship between an 
antenna of a moving object station (mobile station) and a multi-antenna 
constructed of a plurality of plane unit antennas. 
FIG. 3 is a schematic block diagram for indicating an overall system 
arrangement of the information transmitting system according to an 
embodiment of the present invention. 
In FIG. 1, reference numeral 1 indicates a flat plane unit antenna, for 
example, a dipole antenna. Reference numeral 2 is a matching device such 
as a matching transformer used to achieve an impedance matching. Reference 
numeral 3 shows a feeder for connecting the plane unit antenna 1 to the 
matching device 2. A small block is arranged by, for instance, two sets of 
plane unit antennas 1, the matching device 2 and the feeder 3. Reference 
numeral 4 is a coaxial cable. Reference numeral 5 shows a small block 
coupling device constructed of a transformer used to couple a plurality of 
small blocks, e.g., four blocks a1, a2, a3, a4. Further, reference numeral 
6 denotes an amplifier connected to the coupling device 5. As described 
above, for example, a plurality of large blocks "A (A1, A2, - - - ,)" are 
constructed by the four small blocks "a". Further, all of the large blocks 
A1, A2, - - - , are combined with each other by a large block coupling 
device 7, and the combined large blocks are connected to a fixed station 
9. 
Thus, a plane multi-antenna 10 is arranged in such a manner that a large 
number of plane unit antennas 1 are arranged to be mutually coupled with 
each other in a plane manner. 
In this embodiment, the plane unit antenna 1 has a triangle shape as shown 
in the drawing. This is the generic shape of the well-known fan-shaped 
antenna having a dimension "l" being nearly equal to (.lambda./6) to 
.lambda. (symbol ".lambda." denotes a wavelength of a radio transmission 
signal) and an angle ".theta." being nearly equal to 30 to 90 degrees. 
Such a fan-shaped antenna is described in, for example, the 
above-described publication No. 3. A frequency of a carrier wave of this 
information transmission signal is selected to be approximately 100 MHz to 
10 GHz. This condition when the triangle-shaped plane unit antenna is 
employed is similarly used in the following embodiment. 
In FIG. 2, the plane unit antennas 1 are arranged with a predetermined 
interval on a shield setting plate 14. Each interval is constructed of 
either space, or a dielectric substance 11. The shield plane 14 reduces 
external noise, and also effectively functions as a means for emphasizing 
field strengths with respect to the travel surface. 
Reference numeral 12 shows a travel plate for constituting the travel 
surface along which a mobile station 20 is traveled. Reference numeral 13 
indicates a pacer for holding the travel plate 12 and the shielding round 
plate with keeping a constant interval. 
Alternatively, the dielectric substance 11 may be employed between the 
plane unit antenna 1 and the shielding ground plate 14, and between the 
travel plates 12. A mobile antenna 21 is provided on the mobile station 20 
in such a manner that this mobile antenna 21 is located near the plane 
multi-antenna 10. As an example of the mobile antenna 21, a simple 
rod-shaped antenna (containing a rod antenna) is illustrated. It should be 
noted in this example that the moving object corresponds to a 
remote-controlled no-man self-driving car, and a picture (video 
information) of a television camera mounted on this self-driving car can b 
observed by the fixed station. 
Reference numeral 22 is a television camera, and reference numeral 23 shows 
a transmitter. A picture imaged by the television camera 22 is transferred 
via a signal line 24 to the transmitter 23 so as to be frequency-modulated 
(FM), for instance. The FM signal is outputted via the mobile antenna 21. 
Reference numeral 38 shows a drive operation apparatus of the mobile 
station. 
It should be noted that materials of these antenna and shielding ground 
plate are metal materials, for instance, copper, aluminum, iron plates or 
meshes. Both of the travel plate and the dielectric substance are 
non-metal materials, for example, ceramics, plastics, fiber plates, or 
meshes. As a typical example of plastic, a polyester film and an expanded 
foam are involved. 
The plane multi-antenna is preferably constructed as an integral body by 
sandwiching the travel plate, the plane multi-antenna, and the shielding 
ground plate with the dielectric substance. Furthermore, the plane antenna 
is constructed of at least a flexible material, so that this flexible 
plane antenna may be transported to any places, stored and installed 
therein. 
With the above-described arrangement, other than the picture (video) 
information, for example, audio (voice) information acquired by a 
microphone (not shown), and positional data of a GPS (Global Positioning 
System by Satellite) signal may be transmitted from the transmitter 23 of 
the mobile station. Also, a video reproducing apparatus such as a VTR is 
employed instead of the television camera, and video information derived 
from the video reproducing apparatus may be transmitted. 
As previously described, FIG. 3 shows a system arrangement of this 
embodiment. 
As illustrated in this drawing, normally, there are plural mobile stations 
20. In this case, there are three mobile stations 20a, 20b, 20c, which 
transmit the above-described picture signal by carrier frequencies of a 
channel 1, a channel 2, and a channel 3. Reference numerals 21a, 21b, 21c 
indicate antennas of the mobile stations 20a, 20b, 20c, respectively. 
The fixed station 9 is arranged by a distributor 93 and three sets of 
receiver monitors 92a, 92b, 92c for the channels 1 to 3. A signal supplied 
from the mobile stations 20a, 20b, 20c via the multi-antenna 10 and the 
coupler 7 is distributed by the distributor 93 to the respective receiver 
monitors 92a, 92b, 92c. In each of these receiver monitors, a desired 
channel is selected to demodulate the transmitted signal, so that a 
picture of this transmitted signal may be obtained. 
FIG. 4 explanatorily shows a signal path of a radio signal transmitted 
between an antenna of a mobile station and a plane multi-antenna. 
In this drawing, there are represented a signal path ".alpha." and signal 
paths ".beta.1" and ".beta.2" in such an arrangement that an antenna 21 of 
a mobile station is positioned close to a plane multi-antenna 10. Along 
the signal path .alpha., an output from an antenna 21a of a mobile station 
20a is directly radio-transmitted to the multi-antenna 10. Along the 
signal paths .beta.1 and .beta.2, the output from the antenna 21a is 
reflected from side walls of the surroundings and the disturbances, i.e., 
reflected antenna outputs from another mobile station 20b in this drawing. 
In this drawings, reference numerals 22a and 22b designate television 
cameras, and 21b an antenna. 
This indicates that there are a plurality of radio transmission paths from 
the antenna 21a to the plane antenna 10. This implies that multi-path 
problems occur. 
As a consequence, to prevent the multipath problems, a distance .alpha. of 
the signal path must become .alpha.&lt;.beta.1+.beta.2. 
To this end, for instance, the signal path a along which the antenna output 
is directly radio-transmitted may preferably set in such a manner that 
this path .alpha. should be shorter than, or equal to a constant value 
with respect to a wavelength ".lambda." of a radio-transmitted signal 
frequency, namely 0.ltoreq..alpha..ltoreq.5.lambda., preferably 
0&lt;.alpha..ltoreq.2.lambda. more preferably .alpha..ltoreq.2, and 
.alpha..ltoreq..lambda./2 as an optimum value. This condition is similarly 
applied to the respective embodiments. 
That is, the antenna of the mobile station and the plane multi-antenna are 
closely positioned so as to satisfy the above-described value, so that 
information is radio-transmitted between these antennas. As a result, when 
the picture information is transmitted between the transmitter antenna and 
the receiver antenna, since the shortmost signal path located at the 
nearest position between the transmitter antenna and the receiver antenna 
is stronger than other multi-path signal paths, it is possible to 
relatively neglect the multipath caused by the reflections of the 
transmitted/propagated signals, occurrences of standing waves, phase 
shifts, fading phenomena, disturbances of signals, and deterioration of 
S/N (signal-to-noise). The levels of the image quality can be maintained, 
so that such picture information with better quality and wide bandwidth 
may be obtained irrelevant to the positions of the moving object. 
It should be noted that when the antenna of the mobile station is located 
extremely close to the plane multi-antenna, the reception signal is 
adversely influenced by variations in the field intensity distribution at 
the boundaries among the adjoining unit antennas along the travel 
direction of the mobile station. To avoid such an adverse influence, the 
interval may be selected to have such a value as .alpha.&gt;.lambda./50, 
taking account of expansion of directivity of the field intensity 
distribution. This interval is similarly applied to the below-mentioned 
various embodiments. 
It should also be noted that the bandwidths of the picture information 
transmissions with respect to the carrier wave of the picture information 
transmission frequency are different from each other, depending upon the 
modulation methods. When the frequency modulation (FM) is employed, the 
wider the bandwidth becomes, the better the signal-to-noise ratio becomes, 
so that more effective picture information transmission can be achieved 
with respect to the surrounding noise. As a consequence, in the case of FM 
modulation, for instance, the bandwidth of the signal transmission is 
preferably selected to be wider than approximately 6 MHz. 
It should be understood that since the transmitter antenna is located close 
to the receiver antenna, the transmission power may become very low. For 
example, the field strength of the transmission station may be set to be 
lower than, or equal to 500 .mu.V/m under a distance of 3 m. This 
condition may be similarly applied to the following respective 
embodiments. 
Referring now to FIG. 5 to FIG. 7, another example of an arrangement to 
combine the plane unit antennas with each other in accordance with this 
embodiment will be explained. 
Plane multi-antennas shown in FIG. 5 are arranged in such a manner that 
when a travel surface is extended along a long distance, a plurality of 
large blocks, for instance, four large blocks A1 to A4 for the 
multi-antennas as shown in FIG. 1 to FIG. 3 are set to one small group, 
and then a plurality of such small groups (A1 to A4, A5 to A8, A9 to A12, 
A13 to A16, A17 to A20, - - - ) are arranged along the travel surface. The 
respective small groups are combined with each other via an amplifier 6 by 
a coupler 7-1. Further, a plurality (e.g., two) of small groups located 
adjacent to each other are combined with each other by a coupler 7-2 to 
become a middle group. In addition, a plurality (two) of middle groups 
located adjacent to each other are combined with each other by a coupler 
7-3 to become a large group. Then, all of these large groups are combined 
with each other by a coupler 7-4 to be connected to the fixed station 9. 
Although the multi-antenna groups of FIG. 5 are constructed by the 
four-staged layer, this is one of typical examples. Therefore, the stage 
number of the antenna groups may be selected to be a proper value, 
depending upon the scales of the plane multi-antenna. 
It should be noted that when the travel surface is made circular, the first 
large block (e.g., A1) in a large number of large blocks may be connected 
to the last large block (e.g., An), so that the large block is connected 
in an endless form. 
FIG. 6 shows such another arrangement for a plan view of plane unit 
antennas. That is, four sets of plane unit antennas are set to constitute 
a single small block "b" (b1, b2, - - - ), and two small blocks are 
connected to each other by way of a coupler 5 to constitute a large block 
"B" (B1, B2, - - - ). In this drawing, the same reference numerals shown 
in FIG. 1 represent the same components. It is widely known in the art 
that since the line lengths "l2" from the branch point 3 of the feeder to 
the respective antenna elements are equal to each other in this small 
block, the wider bandwidth of the picture information transmission 
frequency can be covered, as compared with the small block "a" of FIG. 1. 
In case of this embodiment, it is practically possible to cover the 
frequency bandwidth equal to a half of the carrier frequency. 
With such an arrangement, the plane multi-antenna may be constructed by 
coupling n (symbol "n" being an integer greater than, or equal to 2) 
pieces of small blocks "b", and by further coupling these small blocks "b" 
with m (symbol "m" being an integer larger than, or equal to 2) pieces of 
blocks "B", if necessary. 
Since the plane multi-antenna owns such a structure, a plurality of plane 
unit antennas are formed in the block unit. The resultant plane unit 
antenna blocks are successively expanded so that the plane multi-antenna 
having various shapes can be arranged. Thus, the system may be easily 
extended. 
FIG. 7 is a plan view for indicating another constructive example of the 
plane multi-antenna. 
In this drawing, a small block "c" is arranged by a small block antenna 
unit c-1 (same as the small block "b" of FIG. 6) made of four unit 
antennas 1 connected to a coupler 5, and another small block antenna unit 
c-2 made of four unit antennas 1 not connected to the coupler 5. A large 
block C is constructed by combining such small blocks "c", for instance, 
two small blocks c-1 and c-2 with the coupler 5. 
Even when the small block unit c-1 is positioned opposite to the small 
block unit c-2 and this small block unit c-2 is not connected to the 
coupler 5 but opened, the electromagnetic waves are reflected and 
emphasized by the effects of the plane unit antenna, so that the actual 
effective area of the plane unit antenna can be enlarged and thus be 
constituted at low cost. Since a total number of wiring connections i the 
example of FIG. 7 is smaller than that of the example shown in FIG. 6, the 
plane antenna may be readily extended. 
FIG. 8 represents such a structure that two plane unit antennas 1 for 
constituting the small block "d" are mutually shifted along the 
longitudinal direction of the travel surface, and the unit antennas are 
arranged in a zig-zag form as an overall multi-antenna. In FIG. 9, there 
is shown an example of such an antenna arrangement that the respective 
block antennas are mutually shifted in a zig-zag form along a direction 
perpendicular to the longitudinal direction of the travel surface. As 
illustrated in the antenna structures of FIG. 8 and FIG. 9, when the unit 
antennas are arranged in a zig-zag form, the following advantages may be 
achieved, as compared with the antenna structure in which the unit 
antennas are not arranged in a zig-zag form (see FIGS. 1, 6 and 7). That 
is, the zig-zag formed antenna structure can reduce the low field 
intensity locations caused by directivity of the antennas existing in the 
intervals of the respective plane unit antennas, so that differences in 
the strengths of the directivity can be mitigated. 
It should be noted that each of the multi-antennas shown in FIG. 6 to FIG. 
9 may be structured by such a hierarchical structure of groups as 
illustrated in FIG. 5. 
FIG. 10, FIG. 11A, FIG. 11B, FIG. 12A and FIG. 12B illustrate other 
structural examples of the plane multi-antenna. In these structural 
examples, with respect to the antenna 21 of the mobile station, the 
multi-antenna 10 employed in the fixed station is not arranged within the 
travel plate 25, but specially separated from this travel plate 25. FIG. 
10 represents that the multi-antenna employed in the fixed station is 
arranged above the moving object, for instance, ceiling. FIGS. 11A, 11B, 
12A and 12B, the multi-antenna of the fixed station is arranged on a side 
wall of the moving object in a travel space. Namely, this antenna is 
arranged along a direction perpendicular to the drawing plane. In these 
drawings, reference numeral 26 is a ceiling, and reference numeral 27 is a 
side wall. The mounting condition of the antenna 21 in the mobile station 
and the structure of the multi-antenna employed in the fixed station shown 
in FIGS. 11A and 11B are different from those of FIG. 12A and 12B. FIGS. 
11A and 12A are sectional views for showing the moving object and the 
multi-antenna provided on the side of the fixed station. 
It should be noted that each of the multi-antennas shown in FIG. 10, FIGS. 
11A, 11B and FIGS. 12A, 12B may be structured by such a hierarchical 
structure of groups as illustrated in FIG. 5. 
FIGS. 11A and 11B are side views for showing multi-antennas provided in the 
fixed station. 
In the case of FIG. 11A, the antenna 21 of the mobile station 20 is 
positioned parallel to the multi-antenna as well as the travel surface. In 
the case of FIG. 11B, the antenna 21 is positioned parallel to the 
multi-antenna and perpendicular to the travel surface. 
In the case of such a mobile station 20 having the antenna 21 shown in FIG. 
11A, when the mobile station is travels on the rail (travel surface), 
there is no problem in the signal reception on the side of the fixed 
station. However, when the mobile station 20 happens to slip and the head 
portion of the mobile station would be directed to a direction 
perpendicular to the travel direction, the antenna is directed normal to 
the multi-antenna 10 of the fixed station, so that the signal receiving 
sensitivity by the multi-antenna would be considerably lowered. On the 
other hand, in the case of FIG. 12A, since the antenna 21 is still located 
parallel to the multi-antenna 10 provided in the fixed station even in 
such a case, the signal receiving sensitivity by the multi-antenna is not 
lowered, and therefore the signal can be transmitted/received under stable 
condition. 
FIG. 13A to FIG. 13F represent a modified example of the plane unit antenna 
shown in FIG. 1 to FIG. 9. FIG. 13A shows a triangle-shaped unit antenna, 
FIG. 13B indicates a rectangular unit antenna, FIG. 13C denotes a 
semicircular unit antenna, and FIG. 13D indicates a circular (otherwise, 
elliptical unit antenna) unit antenna. These directivity characteristics 
are substantially equal to the directivity characteristic of the basic 
plane unit antenna 1 having the triangular shape, namely, the directivity 
of the well known three-dimensional spherical shape and elliptical shape 
(see FIG. 15A). 
FIG. 13E shows a triangle-shaped unit antenna, FIG. 13F indicates a 
rectangular-shaped unit antenna, FIG. 13G denotes a semicircular-shaped 
(or, semi elliptical-shaped) unit antenna, and FIG. 13H represents a 
circular-shaped (or, elliptical-shaped) unit antenna. In these antenna 
structures, the feeders 3 are positioned outside these unit antennas, and 
the shortcircuit line 27 of the shield ground plate 14 is provided at a 
center position of the unit antenna. The directivity characteristic of 
these unit antennas becomes the well known doughnut-shaped characteristic. 
It should be noted that any one of the above-described plane antennas shown 
in FIG. 13A to FIG. 13H may be arranged in such a way that a large number 
of plane antennas are installed as shown in FIGS. 1 to 9 and other 
embodiments (will be discussed later) to constitute a plane multi-antenna 
10. 
FIG. 14 illustratively indicates such an antenna structure in which, in 
order that the major portions of various plane multi-antennas 10 as 
previously stated and will be explain hereinafter are made of a flexible 
material, each of the plane unit antennas 1 is manufactured in a mesh form 
by using a conductive line material. Furthermore, not only the material of 
the travel plane, but also the material of the dielectric 1 positioned 
between the travel plate and the unit antenna as well as the material of 
the shield ground plate (not shown) are made of such a flexible material. 
With the above-described structures, since the multi-antenna can be readily 
transported, stored, and installed, the multi-antennas can be easily 
assembled at the necessary places and be operated. 
It should be understood that the shapes of the antenna 21 provided in the 
mobile station may be made of elements extended along two directions at a 
substantially right angle, other than a simple rod-shaped element so as to 
transmit/receive electromagnetic waves in the above-described and 
below-mentioned embodiments. For example, in a coil-shaped antenna, the 
respective coil surfaces are arranged substantially parallel to the plane 
multi-antenna 10. Since such a coil-shaped antenna is used, the antenna of 
the portable station owns the non-directivity. Even when the portable 
station 20 is traveled not along the travel surface, but is rotated along 
the right angle direction, or the reverse direction, counter positionings 
between the wave propagation planes among the antennas and the directivity 
(in particular, counter positionings among a direction of a dipole unit 
antenna, a direction of the antenna 21 in the portable station, and the 
wave propagation plane) are continuously carried out, so that a signal 
having a relatively better quality can be continuously 
transmitted/received. 
FIGS. 15A and 15B are operation explanatory diagrams in such a case that in 
a plane multi-antenna provided on the side of the fixed station, each of 
the plane unit antennas are installed either in parallel (FIG. 15A) to, or 
inclined (FIG. 15B) with respect to the antenna of the portable station. 
In the drawings, reference numerals 28 and 29 indicate directivity of 
field strengths. 
In the antenna structure of FIG. 15A, there are some possibilities that the 
field strength ".rho." is substantially equal to the field strength 
".sigma." at the antenna 21, depending upon the directivity of both unit 
antennas, near the boundaries among the antenna 21 of the portable 
station, and the plane unit antenna 1-1, 1-2. 
At this time, if there is no phase difference in .rho. and .sigma., then no 
problem occurs. However, if there is a phase difference, then a difference 
(.rho.-.sigma.) between the field strengths at the respective unit 
antennas 1-1 and 1-2 with respect to the plane unit antenna becomes 
extremely small. As a consequence, when there exists a phase shift between 
the signals received by the plane unit antennas 1-1 and 1-2, signal 
deterioration of the received picture information may occur. 
On the other hand, when as shown in FIG. 15B, directivity of the plane unit 
antennas 1-1 and 1-2 is inclined (an inclined angle ".gamma." is selected 
to be smaller than, or equal to 45 degrees in this case) with respect to 
the radio signal transmitted from the antenna 21 of the portable station, 
there are many cases that a relationship of field strengths between .rho. 
and .sigma. becomes approximately .rho.&gt;.sigma. near the boundary between 
these unit antennas 1-1 and 1-2. When there is a phase shift in the 
signals received between the plane unit antennas 1-1 and 1-2, a difference 
(.rho.-.sigma.) in the field strengths at the respective unit antennas 1-1 
and 1-2 with respect to the antenna 21 of the mobile station becomes 
approximately ".rho.". Thus, there is less deterioration in the signals of 
the received picture information, and the necessary signal level is 
maintained. Furthermore, the effective range of directivity of the unit 
antenna is widened, as compared with that of FIG. 15A. Namely, the 
effective range of FIG. 15A case with respect to the antenna 21 of the 
portable station becomes "B", whereas that of FIG. 15B case becomes "A". 
Therefore, mutual interference between these plane unit antenna can be 
suppressed. 
Also, a difference between a field strength B and a field strength A 
becomes A-B&gt;0. The field strength B is defined at the travel surface when 
directivity of the plane unit antennas 1-1 and 1-2 are perpendicular to 
each other. The field strength A is defined at the travel surface when 
directivity of the plane unit antennas 1-1 and 1-2 are inclined. In 
accordance with the method related to FIG. 15B, the effective components 
of the directivity is extended and the stronger field strength can be 
obtained on the travel surface. 
Subsequently, a description will now be made of an information transmitting 
system capable of realizing a bidirectional communication with employment 
of a multi-antenna, according to an embodiment of the present invention. 
First, two examples related to bidirectional communications effected 
between a mobile station and a fixed station will now be described. 
When in the fixed station of FIG. 1 and FIG. 2, a transmitter is further 
employed in addition to a receiver apparatus, whereas an receiver is 
further employed in addition to a transmitter apparatus in the mobile 
station, a simple information transmitting system capable of performing a 
bidirectional communication can be arranged. An arrangement of FIG. 16 is 
an example realized y modifying the systems of FIG. 1 and FIG. 2 in the 
above-described manner. 
In this case, in order that all of the mobile stations can transmit/receive 
the information at the same time, separate channels with different carrier 
frequencies must be allocated to a single mobile station for an up stream 
(namely, from mobile station to fixed station), and a down stream (namely, 
from fixed station to mobile station). Also, to perform a simultaneous 
transmission/reception, in an FM modulation system, at least such a 
frequency bandwidth must be set to proper values in accordance with the 
frequency modulation width in order to prevent mutual interference between 
the carrier frequency of the up stream channel and the carrier frequency 
of the down stream channel. For instance, 291 MHz is allocated to the 
carrier frequency of the up stream channel, and 288 to 294 MHz are 
allocated to the frequency bandwidth, whereas 303 MHz is allocated to the 
carrier frequency of the down stream, and 300 to 306 MHz are allocated to 
the frequency bandwidth in one pair of directional communications. With 
such a frequency allocation, a common antenna for signal 
transmission/reception purposes may be employed via a shared device by the 
respective mobile station and fixed station. 
In FIG. 16, there is shown an example of an arrangement of such an 
information transmitting system capable of transmitting picture 
information in a bidirectional manner. FIG. 17 is a schematic block 
diagram for showing an example of a structure of the mobile station in 
FIG. 16. 
In correspondence with the system of FIG. 16, the mobile station of FIG. 17 
performs a simultaneous transmission/reception by allocating one channel 
as an up stream and one channel as a down stream to a single mobile 
station with using a shared device 31 and a bidirectional communication 
transmitter. 
Here, both of the mobile station and the fixed station are general stations 
such that filtering circuits having the up-stream/down-stream frequency 
bandwidths in the shared device are well known filtering devices, the 
receiver converts the received signal into the intermediate frequency 
signal, and thereafter demodulates the intermediate frequency signal to 
derive the control, video and audio signals, thereby producing picture 
display and audio output. Also, the transmitter is such a well known 
apparatus for modulating the control, video and audio signals to transmit 
the modulated signals. 
A mobile station 30 is constructed of a shared device 31 for the mobile 
station, a mobile station transmitter 23 for amplifying and modifying such 
information signals as video information and video relation information, 
and a mobile station receiver 32 for 
amplifying/filtering/frequency-converting/demodulating such information 
signals as video information and video relation information. These mobile 
station transmitter 23 and receiver 32 are well known in the art. 
Two different channels for transmission and reception purposes are 
allocated as signal channels for radio-transmitting information such as 
pictures to each of the plural mobile stations 30. 
On the other hand, in the fixed station, the amplifier 6 of FIG. 1 is 
changed into a bidirectional amplifier 33. This fixed station is further 
comprised of a shared device 34, a bidirectional amplifier 35 having a 
bidirectional amplifying function, and a shared device 36 for the fixed 
station having a coupling and distributing function. The information is 
collected and distributed by the shared device 36 for the fixed station. 
Reference numeral 91 indicates a bidirectional communication fixed 
station. Reference numeral 37 shows a transmitter/receiver of the fixed 
station, which is well known in the art, and performs 
amplification/filtering/frequency convention/modulation/demodulation of 
information signals such as video information and video relation 
information. 
The information (for instance, information to control the mobile station) 
from the fixed station 91 is supplied from the transmitter/receiver 37 via 
the shared device 36 for the fixed station and the bidirectional amplifier 
35 to be amplified. Then, this information is amplified by the shared 
device 34 and the bidirectional amplifier 33 to become a necessary level, 
and the amplified information is distributed to the respective antenna 
large blocks A1, A2, - - - . Further, in each of the antenna large blocks, 
the amplified information signals are transmitted/distributed to the 
respective plane unit antennas 1, while establishing a matching through a 
coupler 5 and a coupler 2 (not shown). The channel signals specific to the 
respective mobile stations are received by the antenna 21 of the 
respective mobile stations. Furthermore, these specific channel signals 
are received via the shared device 31 for the mobile station by the 
receiver 32 for the mobile station. The received information is supplied 
to the operation apparatus 38 so as to be utilized as remote control 
information for controlling the travel direction and speed of the mobile 
station. Also, the received information is displayed on a monitor 39 and 
may be reproduced by a speaker 40. 
As previously explained, the video information and the like derived from 
the mobile station are transmitted from the transmitter 23 of the 
respective mobile stations 30 via the shared device 31 for the mobile 
station by the antenna 21 in the up stream channel having the different 
frequency from that of the down stream channel. At this time, the 
speed/position information of the mobile station may be transmitted from 
the drive operation apparatus 38 via the transmitter 23. 
Now, in the transmitter/receiver 37 provided ont he fixed station side, the 
information derived from a preselected mobile station is transferred to 
another preselected mobile station, so that the bidirectional 
communication can be established between the mobile stations. For example, 
a specific mobile station transmits information through the own up-stream 
channel CH1 to the fixed station, whereas this fixed station transmits 
this information to another specific mobile station different from the 
above mobile station by using the down stream channel CH4 of this specific 
mobile station operated as a counter party. 
As described above, for example, when such specific channel allocations are 
made that one specific mobile station uses the up stream channel CH1 and 
the down stream channel CH2, whereas another specific mobile station uses 
the up stream channel CH3 and the down stream channel CH4, the 
simultaneous bidirectional transmission/reception can be simply realized 
between the specific mobile stations. 
It is understandable from the above-described embodiment that with 
employment of the structures of the multi-antennas according to the 
present invention, the information can be transmitted/received between the 
mobile station and the fixed station over the travel range of the mobile 
station. 
Then, referring to FIG. 17, an example of a robot (corresponding to the 
mobile station) capable of performing the bidirectional communication. 
In the case when the mobile station 30 is a load carrying robot, the 
operation control apparatus 38 corresponds to a robot control apparatus 
for radio-controlling a moving direction, a speed, and a moving distance 
of this robot. Other reference numerals have been previously described. 
This system is installed within a factory in which the plane multi-antenna 
10 as shown in FIG. 1 is transported by a robot, the robot corresponding 
to the mobile station 30 is traveled on a travel surface, and information 
is radio-transmitted in an arbitrary frequency band between the robot and 
a control room provided on the fixed station side. Also, this system may 
be utilized as such a transmission system that video (picture) information 
and related information required for the mobile station 30 and the robot 
corresponding to another mobile station are transmitted/received in the 
radio signal mode between them. For instance, while observing the video 
information acquired by the television camera 22 of the mobile station 30 
mounted on the robot, the operator at the fixed station 91 transmits the 
direction, speed, travel distance of this robot to the mobile station as 
the related information of the operation control apparatus 38, so that the 
remote control operation can be carried out. 
Further, such an information transmitting system may be utilized as an 
information radio transmitting system such that the information is 
transmitted between an operation instructing room provided at the fixed 
station and a load lift-up portion of a crane car functioning as the 
mobile station. Also, this system may be used as an information radio 
transmitting system in which the information is radio-transmitted between 
a camera car for imaging a field corresponding to the mobile station and a 
broadcasting room provided in the fixed station. When the communication 
system with employing the multi-antenna according to the present invention 
is applied in a field or an acting room, such detailed information about 
moving viewers may be transmitted from a broadcasting room to the inside 
of the fixed station. Also, as train and automobile operation systems, 
detailed information about drive operations are radio-transmitted between 
the train or automobile as the mobile station, and an instruction room 
provided in the fixed station for the drive management. The systems shown 
in FIGS. 16 and 17 may be applied to the above-described multi-antennas 
and the below-mentioned multi-antennas. 
In FIG. 18, there is represented such an embodiment that the present 
invention is applied to a picture radio transmission system for an 
elevator. In this drawing, reference numeral 40 shows a car of an 
elevator, and other reference numerals indicate the same elements as shown 
in FIG. 1. With such an arrangement as shown in FIG. 18, a picture within 
the elevator car 40 is picked up by a television camera 22, and then is 
transmitted via the transmitter 23 and the antenna 21 by the multi-antenna 
10 so as to be monitored by the fixed station 9. 
In the fixed station 9, the reception information signal from the coupler 7 
is received by the receiver 94 and the picture (video) output is sent to a 
monitor and the like. It should be noted that the multi-antenna 10 is 
arranged along the rail of the elevator car 40 corresponding to the mobile 
station, and the structure of this multi-antenna may be constructed as any 
one of the above-described or the below-mentioned multi-antennas. 
In accordance with this embodiment, it is also possible to arrange as 
follows. That is, the information may be sent from the fixed station 9 via 
the multi-antenna 10 to the elevator car 40, and then may be reproduced in 
this elevator car 40 to be displayed ont he monitor. In such a case, as 
the system arrangements of the fixed station and the elevator care, those 
of the previous embodiments shown in FIG. 16 and FIG. 17 may be employed. 
The information transmitting system as illustrated in FIG. 18 may be 
applied to a rail road system in which the multi-antenna 10 may be 
provided along the rail. 
As previously described, in the information transmitting system according 
to the above-explained respective embodiments, the qualities of images 
contained in such information as the picture (video) information with the 
wide bandwidth can be maintained. Then, the picture information with 
better qualities and the acquired relative information can be easily 
captured at any positions within the travel range over which the moving 
object can be traveled. 
In addition to the above-described merit, the following advantages can be 
achieved in accordance with the respective embodiments: 
1). Even when various standing waves of the transmitted signals caused by 
the multipath happen to occur during the transmission of picture 
information between the transmitter antenna and the receiver antenna, the 
distance between the transmitter antenna and the receiver antenna is set 
to a proper value, so that signal disturbances and deterioration in the 
S/N radio can be relatively reduced to be negligible low. These signal 
disturbances and S/N deterioration are caused by the fading phenomenon and 
the phase shifts due to the nearmost located shortest path and other 
paths. As a consequence, qualities of the information such as images can 
be maintained. 
2). Since the multi-antennas of the fixed station are entirely provided 
along the travel surface of the mobile station, the antenna of the mobile 
station is continuously positioned opposite to the multi-antennas of the 
fixed station, so that the information with the wide bandwidth and having 
a level higher than a constant level can be simply and easily obtained. 
3). Since the multi-antenna of the fixed station is located near the 
antenna of the mobile station, the transmission power from the moving 
object is low and can be effectively operated. The apparatus can be made 
simple and at low cost. 
4). The multi-antenna of the fixed station is made in a plane shape, so 
that the plane multi-antenna can be operated to cover the travel range of 
the moving object. Therefore, no longer a large space is required to 
install such a multi-antenna, with is different from the conventional 
antenna installation. 
5). Since the output power of the antenna can be selected to be very low, 
such a range over which the electromagnetic waves outputted from the 
antenna give adverse influences is limited. As a consequence, no adverse 
influences such as radio interference are given to other information 
transmitting systems. 
6). As is known in the field, the bandwidths of the information 
transmitting frequency with respect to the carrier frequency are different 
from each other, depending on the modulation methods. When the frequency 
modulation (FM) system is employed, the wider the bandwidth of the FM 
signal becomes, the better the S/N ratio is improved. Accordingly, the 
information such as video information can be transmitted with better 
characteristics as to the surrounding noise. Furthermore, with respect to 
the S/N ratio, in the case that the travel surface is long, the plane 
multi-antenna is subdivided into several groups, so that the adverse 
influences by the noise and radio interference can be readily lowered. 
7). Since very low electromagnetic waves are utilized, no interference is 
given to other communication means. Also, it is possible to arbitrarily 
set the frequency under use within such a range that no specific stronger 
waves are received from other communication means. 
It should be understood that the above-described effects can be similarly 
achieved in the below-mentioned various embodiment of the present 
invention. 
Next, with reference to FIG. 19 and FIG. 20, a description will be made of 
a plane multi-antenna provided on a fixed station side, according to 
another embodiment of the present invention. That is, in accordance with 
this plane multi-antenna, even when the travel direction of the mobile 
station is varied and thus this plane antenna is not continuously located 
in parallel to the multi-antenna of the fixed station, information can be 
transmitted/received with keeping better quality. 
In FIG. 19 and FIG. 20 reference numerals 1a and 1b represent plane dipole 
unit antennas, respectively. Reference numerals 3a and 3b show feeders for 
the two plane unit antennas 1a and 1b. Reference numerals 2a and 2b 
indicate impedance matching couplers well known in the field. Reference 
numerals 4a and 4b are coaxial cables, reference numeral 54a indicates a 
coupler for coupling the respective plane unit antennas 1a, and reference 
numeral 54b indicates another coupler for coupling the respective plane 
unit antennas 1b. Furthermore, reference numerals 6a and 6b show 
amplifiers connected to the coupler 54a and the coupler 54b. As explained 
above, a large number of such plane unit antennas 1a and 1b are arranged 
to be coupled with each other, so that a plane multi-antenna 10 is 
constructed. This multi-antenna 10 is connected via the respective 
couplers 54a, 54b, the amplifiers 6a, 6b, and further the coupling 
distributors 7a, 7b to the fixed station 9. 
Although not shown in the drawings, a large number of such multi-antennas 
are provided along a travel surface in this embodiment in a similar manner 
to that of the previous embodiment. 
As an example of the plane unit antennas 1a and 1b according to this 
embodiment, the shape of this antenna is a well known triangle as a plane 
dipole antenna similar to the above-explained unit antenna 1. further, a 
dimension "l" of this plane dipole antenna is selected to be nearly equal 
to (.lambda./6) through (.lambda.), and an angle ".theta." thereof is 
selected to be nearly equal to 30 through 90 degrees. Also, a distance 
between the adjoining unit antennas belonging to different groups is 
preferably shorter than, or equal to 2A. 
At this time, the carrier wave of the transmission frequency is typically 
selected to be approximately 100 MHz to 10 GHz. The field strength 
(intensity) of the very low wave is selected to be lower than, or equal to 
500 .mu.V/m at a remote place by 3 m. 
The feature of this embodiment is achieved that the shapes namely, 
directivity and so on of the electromagnetic waves irradiated from the 
multi-antenna constructed from at least two sorts of unit antennas 1a and 
1b are directed to mutually different directions among the respective 
sorts of unit antennas. That is, the unit antennas are arranged n such a 
manner that a difference ".alpha." in the setting angles of the unit 
antennas 1a and 1b for constituting two sorts of unit antenna groups is 
normally selected within a range of 
45.degree..ltoreq..alpha..ltoreq.135.degree.. Preferably, this angel 
difference is selected within a range of 
60.degree..ltoreq..alpha..ltoreq.120.degree., and .alpha.=90.degree. is 
optimum. 
In the embodiment shown in FIG. 19, there are provided two systems 
constructed of a group 1A of the plane unit antenna 1a and also another 
group 1B of the plane unit antenna 1b. 
Alternatively, the above-described two groups 1A and 1B of unit antennas 1a 
and 1b are arranged in such way that more than two sets of antenna groups 
are positioned in parallel thereto along the longitudinal direction of the 
travel surface. Thus, the width of the travel surface may be made wider. 
As in the embodiment of FIG. 20, for instance, two groups of unit antennas 
1c and 1d having the same structures as those of the above-described two 
groups of unit antennas 1a and 1b may be additionally provided. 
In the embodiment of FIG. 20, a positional relationship between the unit 
antenna groups (1c) and the unit antenna group (1d) is identical to that 
between the unit antenna group (1a) and the unit antenna group (1b). 
It should be noted that although two different sorts of unit antenna groups 
have been employed in the embodiments of FIG. 19 and FIG. 20, more than 
three different sorts of unit antenna groups may be used, for example, 
three sorts of unit antenna groups are utilized as shown in FIG. 21. 
The multi-antenna shown in FIG. 21 is arranged by a group 1E of a unit 
antenna 1e, a group 1F of a unit antenna 1f, and a group 1G of a unit 
antenna 1g. A difference ".alpha.1" in setting angles between the unit 
antennas 1e and 1f, and also another difference ".alpha.2" in setting 
angles between the unit antennas 1f and 1g are given as 
45.degree..ltoreq..alpha.1 and .alpha.2.ltoreq.75.degree.. .alpha.1 and 
.alpha.2 are equal to 60 degrees as optimum values. 
Although the unit antennas of the examples shown in FIG. 19, 20, 21 are 
arranged in such a manner that the antenna groups are alternately arranged 
every second group, the unit antennas of the different groups may be 
alternately arranged every plural groups. 
In other words, as illustrated in an example of FIG. 22, a plurality (e.g., 
two) of unit antennas 1a are continuously arranged, and a plurality (e.g., 
two) of unit antenna 1b are arranged adjacent to the first-mentioned unit 
antennas 1a. 
As described above, according to this embodiment a plurality of unit 
antennas are alternately arranged adjacent to each other, these unit 
antennas are constructed of at least one unit antenna having the 
substantially same wave irradiation shapes with each other. The adjoining 
unit antennas are so arranged that directivity of them are different from 
each other. Here, the unit antennas are arranged by a single unit antenna 
in FIG. 19, and by two unit antennas in FIG. 22. Also, such a plurality of 
unit antenna units having the same wave irradiation shapes are combined 
with each other to constitute a single unit antenna group. 
As a result, irrelevant to the positions (namely, antenna directions) of 
the mobile station, both of the mobile station antenna and a single unit 
antenna group of the multi-antenna are continuously located opposite to 
the horizontal and vertical polarized wave-fronts of the electromagnetic 
waves. 
It should be noted that the plane multi-antenna having the structure of 
FIG. 19 may be arranged as the hierarchical structure as shown in the 
example of FIG. 5, as one example indicated in FIG. 23. It should be noted 
that a unit antenna 1bn and another unit antenna 1an+1 are continued along 
the travel surface. 
FIG. 24 is a side view for representing an example of an arranging 
relationship between the respective moving objects corresponding to the 
mobile station, antennas thereof, and the multi-antenna 10 of the fixed 
station shown in any one of FIGS. 19, 20, 22, 23. 
The structures of the mobile stations 20a and 20b are identical to those of 
FIG. 2 and FIG. 4, and descriptions thereof are omitted. It should be 
noted that reference numbers 38a and 38b represent operation (drive) 
control apparatuses. 
Referring now to FIG. 19, FIG. 20, FIG. 24 and FIG. 25, operations of the 
information transmitting system shown in FIG. 24 will be explained. 
In FIG. 19 and FIG. 20, a picture (video) information radio transmission 
signal in a channel CH1 derived from a mobile station 20a, and a picture 
information radio transmission signal in a channel CH2 derived from a 
mobile station 20b are transmitted through the plane multi-antenna 10 and 
amplified by amplifiers 6a and 6b so as to obtain necessary signal levels. 
The amplified transmission signals are processed by distributor/couplers 
7a and 7b having the mixing function to acquire the picture information. 
Then, the processed picture information transmission signals in the 
channels CH1 and CH2 are supplied to the fixed station 9. The respective 
receivers 91-1, 91-2, - - - , employed in the fixed station 9 selectively 
receive the transmission signal in the channel CH1 or CH2, if required. It 
is of course possible to construct that the receivers 91-1 and 91-2 
exclusively select the corresponding channel signals CH1, CH2 by omitting 
the channel selecting functions. 
FIG. 25 is a schematic block diagram for showing an antenna group selecting 
circuit (simply will be referred to a "group selecting circuit" 
hereinafter) 90 (90-1, 90-2) provided in each of the channels CH1 and CH2. 
In this drawing, a group selecting circuit 90-1 exclusively used to the 
channel CH1 is illustrated. It should be understood that the structure of 
the group selecting circuit 90-2 exclusively used to the channel CH2 is 
identical to that of the above-explained group selecting circuit 90-1. 
In FIG. 25, the picture signals of the channels CH1 and CH2 corresponding 
to the antenna outputs derived from two groups 1A and 1B of the unit 
antennas 1a and 1b are entered from the respective coupling distributors 
7a, 7b to a switching circuit 901 of the group selecting circuit 90-1, so 
that one of the picture signals in the channels CH1 and Ch2 derived from 
the selected unit antenna group 1A or 1B by the switching circuit 901 is 
selected to be supplied to the receiver 91-1. The picture signal given to 
the receiver 91-1 is inputted to the group selecting circuit 90-1, and 
then is supplied to signal component extracting circuit, for instance, a 
sync signal separating circuit 902 so as to separate and extract a certain 
featured component of the picture signal, namely the sync signal in this 
example. The extracted sync signal is inputted to a sync signal level 
judging circuit 903. The sync signal level judging circuit 903 detects a 
change in the sync signal levels, and supplies the detection result to the 
switching circuit 901. 
With the above-described circuit arrangement, the picture signal having the 
high reception level among the picture signals received by the different 
antenna groups 1A and 1B is continuously, selectively supplied to the 
receiver 91-1. More specifically, the picture signal outputted from the 
receiver 91-1 is again inputted to the group selecting circuit 90-1, and 
then is furnished to the sync signal separating circuit 902. As is 
generally known, since a sync signal owns a polarity opposite to that of a 
picture signal, these signals can be easily separated from each other. The 
separated sync signal is directly proportional to the transmission 
quality, i.e., constant irrelevant to the output of the picture signal. 
The output of this sync signal is inputted to the sync signal level 
judging circuit 903. When the level of this sync signal is lowered below a 
constant level, this level change is detected and the detection result is 
outputted as a switching instruction. In response to this switching 
instruction, the switching circuit 901 switches the connections in order 
to enter the picture signal derived from another unit antenna group. 
As described above, the antenna outputs from the two series of unit antenna 
groups 1A and 1B are inputted to the group selecting circuit 90 in the 
fixed station 9, and the picture signal derived from one of these unit 
antenna groups selected by this group selecting circuit 90 is transmitted 
to the receiver 91 so as to be demodulated, thereby obtaining the baseband 
picture information. 
Under such a condition, when the respective mobile stations 20a and 20b are 
traveled in a linear form on the travel surface 12 along the longitudinal 
direction of this travel surface, since the wave couplings of the 
propagated waves in the unit antenna group 1A of the plane multi-antenna 
10 during the signal transmission and reception are present along the same 
direction and also the better wave coupling of the propagated waves can be 
achieved, the antenna output signals from the antenna group 1A are 
selected by the group selecting circuits 90-1 and 90-2 of the fixed 
station 9 to be inputted to the receivers 91-1 and 91-2. 
When the respective mobile stations 20a and 20b are traveled along a 
direction perpendicular to the longitudinal direction of the travel 
surface on this travel surface, since the wave couplings of the propagated 
waves in the unit antenna group 1B of the plane multi-antenna 10 during 
the signal transmission and reception are present along the same direction 
and also the better wave coupling of the propagated waves can be achieved, 
the antenna output signals from the antenna group 1B are selected by the 
group selecting circuits 90-1 and 90-2 of the fixed station 9 to be 
inputted to the receivers 91-1 and 91-2. 
When the mobile station 20a is traveled on the travel surface 12 along a 
direction perpendicular to the longitudinal direction of this travel 
surface, since the antenna groups 1A and 1B are selected to each of these 
mobile stations 20a and 20b, the respective receivers can select and 
receive the output signal with the better wave couplings and the better 
quality. 
With the above-described structure, the information such as the wide band 
picture information can be simultaneously obtained in several channels 
under small power, very small power by the simple and low-cost radio 
transmitting system with high quality. It should be noted that the mobile 
station is not always traveled in a linear form along the travel surface 
along the longitudinal direction, but may be traveled along the direction 
perpendicular to the longitudinal direction so as to escape from 
interference. Furthermore, the mobile station may be rotated in the 
reverse direction to be traveled. In any cases, the antennas of the mobile 
station and fixed station can continuously transmit the signal with better 
quality to the selected antenna group whose wave propagation plane and 
directivity are located opposite to those of the first-mentioned antennas. 
Such a structure may be applied to embodiments shown in FIG. 21 to FIG. 
23. When this structure is applied to FIG. 21, the group selecting 
circuits 90-1 and 90-2 select any one of the three groups 1E, 1F and 1G. 
The above-explained embodiment of FIGS. 19 to 25 correspond to such 
embodiments related to the information transmitting system for 
transmitting the information from the mobile station to the fixed station. 
Next, an embodiment about a bidirectional communication system will be 
described. 
FIG. 26 represents an example of an information transmitting system in 
which information about, for instance, a drive control signal of a mobile 
station is transmitted from a fixed station to the mobile station in 
addition to the information transmission system of the picture information 
from the mobile station shown in FIG. 19 to the fixed station. FIG. 27 
shows an arrangement of the mobile station in this case. 
In FIG. 26, radio transmitters 92-1 and 92-2 are provided with the fixed 
station 9, and the radio transmitters own such a function to modulate a 
control signal for controlling the travel directions and the travel speeds 
of the respective mobile stations 20a and 20b and to transmit the 
modulated control signal to the mobile station while observing picture 
output displays at the receivers 91-1 and 91-2 of the fixed station 9. 
Reference numerals 93-1 and 93-2 indicate antennas of the transmitters 
92-1 and 92-2. The information transmitted from the mobile station to the 
fixed station is the picture signal which requires the wide bandwidth, 
whereas since the radio transmitters transmit the simple information in 
this case, such a simple radio communication condition is satisfactorily 
required, namely the bandwidth is lower than, or equal to 100 KHz; the 
frequency is between 10 MHz and 100 MHz in the FM mode. 
The mobile stations 20a and 20b shown in FIG. 27 are arranged by television 
cameras 22a, 22b; transmitters 23a, 23b; antennas 21a, 21b for 
transmitting information such as video information; antennas 731, 732 for 
receiving control signals; control signal receivers 741, 742 for 
converting the received control signal into an intermediate frequency 
signal; and furthermore operation control apparatus 38a, 38b for 
controlling travel directions and travel speeds of the mobile station. 
For instance, the mobile station 20a of the channel CH1 will now be 
explained with reference to the above-described arrangement. First, on the 
side of the fixed station 9, while observing the picture display received 
from the mobile station 20a by way of the receiver 91-1 of the fixed 
station 9 for the channel CH1, the operator operates the radio transmitter 
92-1 to modulate the control signal for controlling the travel direction 
and the travel speed of the mobile station 20a with the carrier frequency 
different from the frequency of the picture reception signal, and 
radio-transmits the FM control signal via the antenna 93. The FM control 
signal is received by the control signal receiving antenna 731 of the 
mobile station 20a, and then the received control signal is converted into 
the intermediate frequency signal and demodulated by the control signal 
receiver 741. In response to this demodulated control signal, the 
operation control apparatus 38a is operated, so that the travel direction 
and the travel speed of the control station 20a are controlled. Such an 
operation is similarly performed also in the mobile station 20b of the 
channel CH2. 
As described above, since at least two antenna groups having different 
directivity from each other, which are constructed of a large number of 
plane unit antennas, are employed in this system, the information can be 
transmitted from the mobile station to the fixed station under stable 
condition. Furthermore, the data information related to the picture 
information such as the control signal from the fixed station to the 
mobile station can be transmitted/received. It should be noted that the 
mobile station is not always traveled in a linear form along the travel 
surface along the longitudinal direction, but may be traveled along the 
direction perpendicular to the longitudinal direction so as to escape from 
interference. Furthermore, the mobile station may be rotated in the 
reverse direction to be traveled. In this embodiment, the fixed station 
can continuously receive the signal with better quality by selecting the 
antenna group whose wave propagation plane and directivity are located 
opposite to those of the first-mentioned antennas. Based on the data 
information such as the control signal, the travel direction and the 
travel speed of the mobile station can be controlled. As a consequence, as 
the actual example of the moving object shown in FIG. 27, a load carrying 
car and a radio-controlled robot are optimum. It should be noted in FIGS. 
26 and 27, the system is arranged in a similar manner to that of FIG. 16 
and FIG. 17, so that the antennas 21a, 21b, and the antenna groups 1A and 
1B may be commonly operated for transmission/reception purposes. 
The bandwidths of the picture information transmission frequency are 
different from each other with respect to the carrier wave, depending upon 
the modulation system. When the FM system is employed, the wider the 
bandwidth becomes, the better the S/N ratio is achieved. By this FM 
system, more effective picture information transmission is available as to 
the surrounding noise. For instance, the transmission bandwidth is 
selected to be higher than, or equal to approximately 6 MHz. 
It should be noted that each of the mobile stations may modulate such 
information related to a video (picture) of a television camera, for 
instance, sound information, or positional information of a GPS (global 
positioning system by satellite) and thereafter may transmit the modulated 
signal (generally speaking, modulating operation of a modulator employed 
in a transmitter is normal). 
As previously explained, the dipole antenna has been described as to the 
unit antenna of the fixed station. The present invention is not limited to 
this dipole antenna, but may be applied to other types of antenna. Also, 
the rod-shaped antenna has been explained as the antenna of the mobile 
station, but the present invention is not limited thereto. 
In accordance with the embodiment shown in FIGS. 19 to 27, there are the 
following effects other than the effects achieved in the embodiments, of 
FIGS. 1 to 18. That is, the picture information with the wide bandwidth 
can be easily, simply obtained as the picture information with better 
qualities and the acquired relative information at any positions, while 
the antenna of the mobile station is continuously located opposite to the 
antenna of the fixed station. In particular, even when the mobile station 
is traveled in any travel directions, signal disturbances and 
deterioration in the S/N radio can be relatively reduced to be negligible 
low. These signal disturbances and S/N deterioration are caused by the 
fading phenomenon and the phase shifts, while maintaining the better image 
quality level. As the better picture information and the related 
information, even where the mobile station is present, the antennas of the 
mobile station and the fixed station are positioned opposite to each 
other, so that constant information can be simply, easily obtained. 
Next, such a multi-antenna used in the information transmitting system 
according to the present invention will be explained. That is, a plurality 
of unit antenna units are alternately arranged adjacent to each other, 
which are constructed of at least single unit antenna existing in an 
electromagnetic wave propagation range that in-phase components of the 
received electromagnetic waves become major components, and the in-phase 
components of the received electromagnetic waves in the mutually adjacent 
unit antenna units are different from each other. FIGS. 28 and 29 show 
information transmitting systems equipped with another example of such a 
multi-antenna. 
In FIG. 28 and FIG. 29, reference numerals 1m and 1n represent plane dipole 
unit antennas, respectively. Reference numerals 3m and 3n show feeders for 
the two plane unit antennas 1m and 1n. Reference numerals 2m and 2n 
indicate impedance matching couplers well known in the field. Reference 
numerals 4m and 4n are coaxial cables, reference numeral 54m indicates a 
coupler for coupling the respective plane unit antennas 1m, and reference 
numeral 54n indicates another coupler for coupling the respective plane 
unit antennas 1n. Furthermore, reference numerals 6m and 6n show 
amplifiers connected to the coupler 54m and the coupler 54n. 
In the embodiment of FIG. 28 and FIG. 29, the unit antenna unit is arranged 
by a single unit antenna, but may be arranged by more than two unit 
antennas. A plurality of unit antenna unit whose in-phase components are 
identical to each other are coupled to each other, thereby forming a 
single antenna group. 
In this case, where are employed a plurality of unit antenna units which 
are made of at least one unit antenna arranged within such an 
electromagnetic wave propagating range that the phases of the received 
waves become in-phase components. A plurality of unit antenna units are 
alternately arranged adjacent to each other in such a manner that the 
in-phase components for constituting the major components waves in the 
mutually adjacent unit antenna units are different from each other. 
In the examples of FIGS. 20 and 29, the antenna is arranged by a unit 
antenna group 1M and a unit antenna group 1Nt. The unit antenna group 1M 
is constructed of a large number of unit antennas 1m each having the same 
directivity, in which the phase of the wave propagation of the antenna is 
present in the range of the in-phase component. The unit antenna group 1Nt 
is arranged by a large number of unit antennas 1n each having the same 
directivity, in which the phase of the wave propagation of the antenna is 
present in the range of the in-phase component. As to the unit antenna 1m 
and the unit antenna 1n, the in-phase components for constituting the 
directivity and the received electromagnetic waves (wave propagation) are 
mutually different. For instance, the unit antenna 1n and the unit antenna 
1n are alternately arranged with an interval smaller than 2.lambda., 
preferably. 
Furthermore, a relative setting angle ".alpha.n" (see FIG. 32A) of 
directivity of adjoining unit antennas for constituting the same group is 
different from each other, depending upon curves of the travel surface. 
Normally, this relative setting angle ".alpha.n" is set to +45 degrees and 
-45 degrees, preferably +30 degrees and -30 degrees, and 0 degree (travel 
surface is straight) under optimal condition. 
FIG. 32A and FIG. 32B are plane views for indicating arrangements of unit 
antennas belonging to the same group. In FIG. 32A, the unit antenna 1m-2 
indicated by a broken line is set to the unit antenna 1m-1 under such a 
condition that the angle ".alpha.n" is selected to be about 10 degrees. 
FIG. 30 is a side view for illustrating a positional relationship among the 
respective moving objects corresponding to the mobile station, the 
antennas thereof, and a multi-antenna 100 provided on the fixed station 
side shown in FIGS. 28 to 29. 
In FIG. 30, as one example, similar to the respective embodiments, the 
plane multi-antenna 100, the feeder and the coaxial cable are arranged via 
either a space or dielectric 11 on a shield ground plate 14, but these 
components other than the antenna may be positioned under the shield 
ground plate 14. Reference numeral 12 is a travel plate having a travel 
surface along which the respective mobile stations 20a and 20b are 
traveled. 
FIG. 31 is a block diagram for showing an arrangement of the group 
selecting circuit 90 which corresponds to the channel CH1. For instance, 
the antenna outputs from the two unit antenna groups 1N and 1M of the 
multi-antenna, whose antenna phases are different from each other, are 
entered to the switching circuit 90-1. Since operation of the group 
selecting circuit 90 shown in FIG. 31 is the same as that of FIG. 25, no 
explanation thereof is made. 
With this arrangement, the output from the unit antenna group 1M or 1N is 
continuously selected to be supplied to the receiver 91-1, which has the 
high level of the picture signal. 
FIGS. 32A and 32B represent unit antennas belonging to the same group, 
i.t., group 1M in this case. FIG. 32A corresponds to FIG. 28, and FIG. 32B 
corresponds to FIG. 29. As shown in FIG. 32A, generally speaking, assuming 
now that a distance between the adjoining unit antennas 1m-1, 1m-2, 
belonging to the same group is "L", another distance between the antenna 
21a or 21b of the mobile station, and the unit antenna 1m-1 is "A", and 
other distance between the antenna 21a, or 21b of the mobile station and 
the unit antenna 1m-2 is "B", as to the phases and the output difference 
of the signals received from the antenna 21a or 21b of the mobile station 
to the unit antennas 1m-1 and 1m-2, the in-phase state is established in 
case of the phase difference ".lambda.", and the outputs of the reception 
levels by the distances A and B of the antennas of the mobile station and 
the fixed station are summed. 
When the distance "L" between the unit antennas, for instance, belonging to 
the same group is set in a manner that the phase difference therebetween 
becomes .lambda./2, the phases of the signals received between the unit 
antennas 1m-1 and 1m-2 are completely opposite to each other, and the 
output from the multi-antenna becomes an output difference in the 
reception levels between these unit antennas, depending upon the distances 
A and B of the unit antennas 1m-1 and 1m-2, namely the output becomes very 
small. 
When the distance between the antennas 1m-1 and 1m-2 is defined by 
L.apprxeq.2.lambda., at a position where the distance A between the 
antenna of the mobile station and the unit antenna 1m-1 is defined by 
A.apprxeq.3.lambda./4, and the distance B between the antenna of the 
mobile station and the unit antenna 1m-2 is defined by 
B.apprxeq.5.lambda./4, then B-A=.lambda./2. Similarly, at a position where 
A.apprxeq.5.lambda./4 and B.apprxeq.3.lambda./4, then A-B=.lambda./2 
(actually, it is not plane, but three-dimensional, and also is not a 
straight line. However, the idea is basically identical). 
In other words, the adjoining unit antennas mutually connected to the same 
group receive the electronic waves having the completely opposite phases. 
That is, a plurality of unit antenna units are alternately arranged 
adjacent to each other, which are constructed of at least single unit 
antenna existing in an electromagnetic wave propagation range that 
in-phase components of the received electromagnetic waves become major 
components, and the in-phase components of the received electromagnetic 
waves in the mutually adjacent unit antenna units are different from each 
other. 
Furthermore, when each of the mobile stations 20a and 20b is traveled in a 
linear form on the travel surface 12 along a predetermined direction, 
within such a range that the antenna outputs are summed at the 
substantially same phases of the electromagnetic waves 
transmitted/received by the group 1M of the plane multi-antenna 10, the 
output signal having the better quality is selected from the group 1M by 
the group selecting circuit 90 of the fixed station 9, and the selected 
output signal can be inputted to the receiver 91. 
Within such a range that the antenna outputs are summed at the 
substantially same phases of the electromagnetic waves 
transmitted/received by the group 1N of the plane multi-antenna 10, the 
output signal with the better quality from the group 1N is selected, and 
can be entered into the receiver 91. With such a structure, the picture 
information having the wide bandwidth can be effectively radio-transmitted 
under small power, very small power by the simple structure manufactured 
at low cost. Also, the mobile station is not always traveled in a linear 
form along the travel surface, but may be traveled along a curved travel 
surface. Even under such a curved surface, correspondence between the 
phase output and the propagation surface of the electronic waves among the 
antennas is selectively performed, so that the signals with better quality 
can be continuously transmitted. Furthermore, when the mobile station is 
traveled in a linear form along the longitudinal direction of the travel 
surface, the signal with the better quality can be continuously 
transmitted. 
The embodiments shown in FIG. 28 and FIG. 29 are such embodiment that the 
information is transmitted from the mobile station to the fixed station 
along one direction. Then, an embodiment about a bidirectional 
communication will now be explained. 
FIG. 33 shows an arrangement of a system according to an embodiment, in 
which in addition to the picture information transmitting system from the 
mobile station to the fixed station within the arrangement of FIG. 29, a 
control signal is transmitted from the fixed station to the mobile 
station. FIG. 34 represents an arrangement of this mobile station. These 
arrangements are similar to those of FIGS. 26 and 27, and explanations 
thereof are omitted. 
As described above, since at least two antenna groups 1M and 1N of the 
plane multi-antennas are employed, the picture information can be 
transmitted from the mobile station to the fixed station under stable 
condition, and furthermore the data information such as the control 
signals can be transmitted/received from the fixed station to the mobile 
station, which is related to the picture information. It should be noted 
that this embodiment is also applied to the embodiment shown in FIG. 28. 
Such an information transmitting system may be utilized in a system that, 
for example, information is sent/received between an elevator car (mobile 
station) and an elevator control monitoring apparatus. It should be noted 
that the mobile station is not always traveled in a linear form along the 
travel surface, but may be traveled along the direction perpendicular to 
the longitudinal direction so as to escape from interference. In 
accordance with this embodiment, the antenna group received by the fixed 
station is selected, so that while the signal having the better quality 
can be continuously received, the travel direction and the travel speed of 
the mobile station can be controlled based on the data information such as 
the control signal. As a consequence, as the actual example of the moving 
object shown in FIG. 34, a load carrying car and a radio-controlled robot 
are optimum. 
The bandwidths of the picture information transmission frequency are 
different from each other with respect to the carrier wave, depending upon 
the modulation system. When the FM system is employed, the wider the 
bandwidth becomes, the better the S/N ratio is achieved. By this FM 
system, more effective picture information transmission is available as to 
the surrounding noise, for instance, the transmission bandwidth is 
selected to be higher than, or equal to approximately 6 MHz. When the 
travel surface becomes for distance, the plane multi-antenna 10 is 
subdivided into such blocks as shown in FIG. 23 to constitute a 
hierarchical structure, so that adverse influences caused by noise and 
interference can be suppressed. 
It should be noted that each of the mobile stations may modulate such 
information related to a video (picture) of a television camera, for 
instance, sound information, or positional information of a GPS (global 
positioning system by satellite) and thereafter may transmit the modulated 
signal (generally speaking, modulating operation of a modulator employed 
in a transmitter is normal). 
In accordance with the embodiment shown in FIGS. 19 to 34, there are the 
following effects other than the effects achieved in the embodiments of 
FIGS. 1 to 18. That is, the picture information with the wide bandwidth 
can be easily, simply obtained as the picture information with better 
qualities and the acquired relative information at any positions, while 
the antenna of the mobile station is continuously located opposite to the 
antenna of the fixed station. In particular, even when the mobile station 
is traveled in any travel directions, signal disturbances and 
deterioration in the S/N radio can be relatively reduced to be negligible 
low. These signal disturbances and S/N deterioration are caused by the 
phase shifts, while maintaining the better image quality level. As the 
better picture information and the related information, even where the 
mobile station is present, the antennas of the mobile station and the 
fixed station are positioned opposite to each other, so that constant 
information can be simply, easily obtained. 
It should be noted that although the transmission channel from the mobile 
station and the transmission channel from the fixed station are different 
from each other in such an embodiment that the information is transmitted 
between the mobile station and the fixed station in the bidirectional 
manner, the time-divisional multiplex system and the speed spectrum 
communication system may be employed with using the same channel. 
Also, in the embodiments of FIG. 33 and FIG. 34, the structure thereof is 
constructed in a similar manner to that of FIG. 16 and FIG. 17, so that 
the antennas 21a, 21b and the antenna groups (1M, 1N) may be commonly used 
to transmit/receive the picture information and/or other information.