High-frequency amplifier device

A high-frequency amplifier device according to this invention comprises a high-frequency amplifier portion, a high-frequency input portion which is formed of a waveguide and which can transmit polarized signals orthogonal to each other, two detector portions which are inserted in the waveguide of the input portion and which respectively and independently detect the polarized wave signals orthogonal to each other, an irreversible circuit to which the polarized wave signals detected by the detector portions are individually input and which selectively and switching delivers one of the polarized wave signals to the high-frequency amplifier portion and returns the other polarized wave signal to the input portion, and a switching control mechanism for switching and controlling transmitting directions of the irreversible circuit in response to a control signal externally applied.

BACKGROUND OF THE INVENTION 
This invention relates to a high-frequency amplifier device which amplifies 
or frequency-converts a feeble electric wave received by an antenna or the 
like. 
FIG. 1 is a setup diagram showing an example of a prior-art high-frequency 
amplifier device, while FIG. 2 is a sectional view showing an example of 
the practicable structure of the high-frequency amplifier device having 
the setup in FIG. 1. In the figures, numeral 1 designates a high-frequency 
amplifier portion, numeral 4 the signal output terminal of the amplifier 
device, and numeral 7 the case of the amplifier device. Numeral 71 
indicates the input flange of the amplifier device, numeral 72 the input 
portion thereof for a high-frequency signal, which is formed of a 
waveguide, numeral 73 the detector portion thereof which detects the 
high-frequency signal transmitted and applied by the waveguide, and 
numeral 74 the irreversible circuit thereof which is represented by an 
isolator. The high-frequency amplifier portion 1 has the function of 
frequency conversion partly or wholly, and the function of high-frequency 
will be explained as a typical example hereinbelow. 
Next, the operation of the prior-art device will be described. The 
high-frequency signal received by the waveguide input portion 72 is 
detected by the detector portion 73, and the detected signal is sent to an 
isolator or the like irreversible element 74 as a coaxial mode or a strip 
line mode. The irreversible element 74 transmits the signal with a low 
loss in the direction of arrows as indicated in the figures, whereas it 
operates to afford a large attenuation to a signal in the reverse 
direction. Now that the input signal is transmitted in the direction of 
the illustrated arrows, it is transmitted to the high-frequency amplifier 
portion 1 with only a low loss. After the input signal is amplified to a 
required level in the high-frequency amplifier portion 1, it is delivered 
out from the signal output terminal 4. The high-frequency amplifier 
portion 1 is so constructed that a plurality of semiconductor amplifier 
elements are arranged at suitable intervals on a strip line which is made 
of a dielectric exhibiting low loss characteristics to high frequencies, 
for example, ceramics or teflon, and that resistors and capacitors for 
supplying D.C. biases to the semiconductor amplifier elements are added. 
Bipolar transistors, field-effect transistors, etc. are extensively used 
as the semiconductor amplifier elements for amplifying the high 
frequencies. The irreversible element 74 is used for improving the input 
impedance of the high-frequency amplifier portion 1, or for preventing the 
high-frequency amplifier portion 1 from causing oscillations etc., under 
the influence of an oscillator impedance on the input side. When viewed 
laterally, the waveguide input portion 72 has a shape as shown in FIG. 3. 
The section of the waveguide input portion 72 is oblong, and the detector 
portion 73 protrudes into the waveguide input portion 72 as shown in FIG. 
2, by way of example. The detector portion 73 detects the input of an 
electric field in the direction of an arrow indicated in FIG. 3, and sends 
it to the high-frequency amplifier portion 1. 
Since the prior-art high-frequency amplifier device is constructed as 
described above, it can amplify only the input of the electric field in 
the direction of the arrow indicated in FIG. 3. Broadcast satellites in 
recent years often send signals by the use of two orthogonal polarized 
waves. The prior-art high-frequency amplifier device as shown in FIGS. 1 
thru 3 has had the problem that, in order to amplify an input signal of an 
electric field perpendicular to the arrow, the input flange 71 of the 
high-frequency amplifier device needs to be detached and then remounted 
with a rotational angle of 90.degree.. Alternatively, an antenna for 
receiving the input signals from the satellite needs to be switched so as 
to receive the perpendicular polarized wave, and to transmit the received 
wave to the high-frequency amplifier device. 
SUMMARY OF THE INVENTION 
This invention has been made in order to eliminate the problem as described 
above, and has for its object to provide a high-frequency amplifier device 
by which two polarized waves orthogonal to each other can be instantly 
switched and received and which can be put into a unitary structure 
directly coupled with the primary radiation system of an antenna. 
A high-frequency amplifier device according to this invention comprises a 
high-frequency amplifier portion, a high-frequency input portion which is 
formed of a waveguide and which can transmit polarized signals orthogonal 
to each other, two detector portions which are inserted in the waveguide 
of the input portion and which respectively and independently detect the 
polarized wave signals orthogonal to each other, an irreversible circuit 
to which the polarized wave signals detected by the detector portions are 
individually input and which selectively and switchingly delivers one of 
the polarized wave signals to the high-frequency amplifier portion and 
returns the other polarized wave signal to the input portion, and 
switching control means to switch and control transmitting directions of 
the irreversible circuit in response to a control signal externally 
applied whereby the two orthogonal polarized wave signals can be switched 
and amplified. 
A high-frequency amplifier portion according to this invention may also 
comprise a high-frequency amplifier portion, a high-frequency waveguide 
mechanism for transmitting first and second polarized signals orthogonal 
to each other, first and second detector portions inserted in the 
waveguide mechanism for detecting the first and second polarized signals, 
respectively, a three-terminal latching circulator having a first terminal 
coupled to the first detector, a second terminal coupled to the second 
detector, and a third terminal coupled to the high-frequency amplifier 
portion, and control means for switching the signal rotating directions of 
the latching circulator in response to a control signal externally applied 
whereby either the first or second signal is supplied to the 
high-frequency amplifier portion while the other signal and any signal 
reflected from the high-frequency amplifier portion are returned to the 
waveguide mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Now, one embodiment of this invention will be described with reference to 
the drawings. In FIG. 4, numeral 1 designates a high-frequency amplifier 
portion, numeral 2 a high-frequency input portion made of a waveguide 
which can transmit two polarized waves orthogonal to each other, numeral 3 
a latching circulator, numeral 4 the signal output terminal of the 
amplifier device, and numeral 5 the case of the amplifier device. The 
latching circulator 3 has signal terminals 31, 32 and 33, and an 
excitation coil 38 which is provided with signal input terminals 70. 
Detector portion 61 and 62 independently detect the two polarized waves 
orthogonal to each other and entering the high-frequency input portion 2, 
respectively. The case 5 is provided with ports 63 and 64 for forming 
coaxial lines, by which signals detected by the detector portions 61 and 
62 are respectively transmitted to the terminals 31 and 32 of the latching 
circulator 3. 
FIG. 5 is a structural view showing an example of the practicable structure 
of the embodiment of the present invention illustrated in FIG. 4, while 
FIG. 6 is a view of the high-frequency amplifier device in FIG. 5 as seen 
from the side of the high-frequency input portion 2 thereof. FIGS. 7 and 8 
are structural views showing an example of the practicable structure of 
the latching circulator 3. In FIG. 8, numeral 34 indicates an inner 
conductor, numeral 35 an outer conductor, numeral 36 a ferrite plate, 
numeral 37 a dielectric plate, and numeral 38 the exciting coil. Symbols 
39a and 39b denote members of a magnetic substance which serve as magnets. 
In such a construction, the input to the high-frequency input portion 2 
consists of the two signals of the polarized waves orthogonal to each 
other having the directions of electric fields 21 and 22 in FIG. 5, which 
are respectively termed a signal H and a signal V, and the detector 
portion 61 is mounted in parallel with the electric field 21, while the 
detector portion 62 is mounted in parallel with the electric field 22. 
When the detector portions are thus mounted, the signal H is detected by 
only the detector portion 61 and is sent to the terminal 31 of the 
latching circulator 3. On the other hand, the signal V is detected by only 
the detector portion 62 and is sent to the terminal 32 of the latching 
circulator 3. Now, let's consider a case where the directions of the 
magnetic fields of the magnets 39a and 39b of the latching circulator 3 
are set so that the directions of rotating signals may become as follows: 
EQU Input to terminal 31.fwdarw.Output to terminal 33 
EQU Input to terminal 33.fwdarw.Output to terminal 32 
EQU Input to terminal 32.fwdarw.Output to terminal 31 
Then, the high-frequency signals flow as stated below. 
The H signal input is detected by the detector portion 61 and is input to 
the terminal 31, and it is output to the terminal 33 with a low loss. 
Therefore, the signal is amplified by the high-frequency amplifier portion 
1 and is delivered from the signal output terminal 4 to another external 
device. 
On the other hand, the V signal input is detected by the detector portion 
62 and is input to the terminal 32 of the latching circulator 3. However, 
this signal is output to the terminal 31 with a low loss and does not 
appear at the terminal 33. The V signal delivered to the terminal 31 is 
output from the detector portion 61 to the high-frequency input portion 2 
as a polarized wave in the direction of the electric field 21 and is sent 
back to an antenna portion (not shown) connected to the input portion 2, 
so that it is not transmitted to the high-frequency amplifier portion 1. 
Moreover, the H signal reflected from the high-frequency amplifier portion 
1 to the terminal 33 on account of the mismatching of the input impedance 
of the high-frequency amplifier portion 1 is transmitted to the terminal 
32 and is also sent back to the antenna portion via the detector portion 
62, so that it is not reflected to the side of the terminal 31. In this 
way, the latching circulator 3 performs the function of mismatching 
elimination similarly to the irreversible circuit 74 of the prior-art 
high-frequency amplifier device in FIG. 1. 
Next, when the V signal is to be amplified, a switching signal is applied 
to the coil 38 to invert the directions of the magnetic fields of the 
magnets 39a and 39b and to perform the signal rotation of the latching 
circulator 3 in the direction of the terminals 
32.fwdarw.33.fwdarw.31.fwdarw.32. Thus, the V signal is detected by the 
detector portion 62 and is thereafter amplified by the high-frequency 
amplifier portion 1 via the terminals 32 and 33, whereupon the amplified V 
signal is delivered from the output terminal 4 to the external device. In 
this case, the H signal is not output to the output terminal 4. 
While the above embodiment has been described as the high-frequency 
amplifier device which switchingly amplifies the two polarized wave inputs 
orthogonal to each other, the invention may well be applied as a 
high-frequency amplifier device which switchingly sends an antenna device 
two polarized waves orthogonal to each other, in such a way that the 
high-frequency amplifier portion is mounted with its input and output 
directions inverted to use the terminal 4 as an input terminal and the 
waveguide 2 as an output terminal. 
In addition, as illustrated in FIG. 9, the case 5 and the waveguide of the 
high-frequency input portion 2 which constitute the high-frequency 
amplifier device of the present invention are put into a structure unitary 
with the primary radiator 9 of an antenna, whereby a front end type 
primary radiator which is small in size and light in weight can be 
realized. 
As described above, according to this invention, an input waveguide is 
fabricated in geometries capable of transmitting two orthogonal polarized 
waves, the waveguide is furnished with detector portions which detect the 
respective polarized waves independently, and the outputs of the detector 
portions can be switched and reveived by a latching circulator. Therefore, 
the invention produces the effect that a high-frequency amplifier device 
which can switch and receive the signals of the desired polarized waves 
with the single amplifier device can be realized inexpensively with a 
simple structure.