Patent Publication Number: US-9837700-B2

Title: Antenna device and portable electronic device

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an antenna device and a portable electronic device. 
     Background Art 
     It is known that conventional GPS (global position system) schemes measure the longitude and latitude of a current location in accordance with GPS signals in GPS radio waves, which are received from GPS satellites via a GPS antenna. One example of such a GPS antenna is a patch antenna. There are also handy terminals equipped with GPS reception units that have a GPS antenna therein, and these terminals can detect current location. 
     Compound antennas, which are provided with a plurality of antennas for detecting radio waves of different frequencies, are also known. Japanese Patent Application Laid-Open Publication No. 2003-152445 discloses a compound antenna that has a patch antenna for transmission and reception of ETC (electronic toll collection system) or DSRC (dedicated short-range communications) signals and that receives radio waves of two different frequencies, for example. Japanese Patent Application Laid-Open Publication No. 2003-163531 discloses a compound antenna that has a patch antenna for transmission and reception of ETC or DSRC signals, a loop antenna for GPS signals, and a loop antenna for receiving radio wave beacons. This compound antenna receives three different frequencies. 
     There is demand for a GPS antenna to be provided in a handy terminal having a reader/writer for RFID (radio frequency identification)/NFC (near-field communication) signals. When a plurality of antennas are provided as in Patent Documents 1 and 2, however, the GPS antenna is disposed in the vicinity of the loop antenna (antenna coil) used for RFID, and the interference between these antennas degrades antenna performance characteristics such as directionality. 
     On the other hand, to ensure the performance of both antennas without interference, it is necessary to install the antennas in locations that are separated from each other at approximately λ/4 of a wavelength of the frequency being used, which hinders miniaturization of the handy terminal. 
     SUMMARY OF THE INVENTION 
     The present invention aims at arranging two antennas in the vicinity of each other while increasing the antenna performance thereof. 
     Additional or separate features and advantages of the invention will be set forth in the descriptions that follow and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings. 
     To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, in one aspect, the present disclosure provides an antenna device, including: a patch antenna having a resonant frequency at a first frequency; and a loop antenna having a resonant frequency at a second frequency that is different from the first frequency, wherein a loop length of the loop antenna is such that standing waves are generated in the loop antenna when the loop antenna receives radio waves of the first frequency, and wherein the patch antenna is disposed so as to magnetically couple with the loop antenna. 
     In one aspect, the present disclosure provides a portable electronic device, including: an imaging unit provided on an end of the portable electronic device; a loop antenna provided so as to surround the imaging unit; and a patch antenna that has a different resonant frequency than a resonant frequency of the loop antenna, wherein a loop length of the loop antenna is such that standing waves are generated in the loop antenna when the loop antenna receives radio waves having a frequency that corresponds to the resonant frequency of the patch antenna, and wherein the patch antenna is disposed so as to magnetically couple with the loop antenna. 
     The present invention makes it possible to arrange a loop antenna in the vicinity of a patch antenna and to increase antenna performance thereof, such as by enhancing a directionality of the antenna so that radio waves of the first frequency propagate in many directions. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an external view of a handy terminal according to one aspect of the present invention. 
         FIG. 2  is a block view of a functional configuration of the handy terminal. 
         FIG. 3  is a perspective view of a patch antenna. 
         FIG. 4  is a perspective view of a loop antenna. 
         FIG. 5  is a perspective view of magnetic coupling when the patch antenna receives GPS radio waves. 
         FIG. 6  is a perspective view of magnetic coupling when the patch antenna receives GPS radio waves. 
         FIG. 7A  is a view of a resonant circuit of the loop antenna. 
         FIG. 7B  is an equivalent circuit of the loop antenna and an RFID driver circuit. 
         FIG. 8A  is a perspective view of the directionality generated by the patch antenna and the loop antenna attached to a substrate. 
         FIG. 8B  is a plan view of the directionality generated by the patch antenna and the loop antenna. 
         FIG. 9  is a plan view of a loop antenna of a modification example, and the patch antenna. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment and modification example according to the present invention will be described in detail below with reference to the accompanying drawings. The present invention is not limited to the examples shown in the drawings. 
     An embodiment of the present invention will be described below with reference to  FIGS. 1 to 8 . First, a device configuration of the present embodiment will be described with reference to  FIGS. 1 to 4 . 
       FIG. 1  is an external view of a handy terminal  1  according to the present embodiment. 
       FIG. 2  is a block view of a functional configuration of the handy terminal  1 . 
       FIG. 3  is a perspective view of a patch antenna  30 .  FIG. 4  is a perspective view of a loop antenna  40 . 
     First, the external configuration of the handy terminal  1 , which is a portable electronic device of the present embodiment, will be explained with reference to  FIG. 1 . 
     The handy terminal  1  is a portable terminal that functions as a symbols reader (for one-dimensional bar codes, two-dimensional codes), an RFID reader/writer, a GPS device, and input/output device for various types of information. 
     The handy terminal  1  is used for item management during deliveries, inventory management, and the like, for example. 
     As shown in  FIG. 1 , the handy terminal  1  has a top case  2   a  and a bottom case  2   b , which are made of resin, and a battery (not shown), substrate  10  (omitted in  FIG. 1 ), and the like between the top case  2   a  and the bottom case  2   b , i.e., inside the handy terminal  1 . The substrate  10  is a PCB (printed circuit board) that has various types of circuit components mounted thereon. 
     The handy terminal  1  has a display unit  14  and keys  12   a  on the flat portion (the top) of the top case  2   a . The display unit  14  is constituted of an LCD (liquid crystal display), EL (electroluminescent) display, or the like, and displays various types of information. 
     The keys  12   a  are constituted of a plurality of keys that receive push operations from the user, such as a menu key, letter (numeral) input keys, cursor keys, trigger keys for RFID reading/writing, and the like. 
     The handy terminal  1  has an imaging unit  19  at the tip of the bottom case  2   b . The imaging unit  19  has an optical system that captures an image of an object and outputs image data, an imaging device, and a processing circuit. In particular, the imaging unit  19  captures the object as symbols, and performs imaging for reading the information of these symbols. 
     The handy terminal  1  has side keys  12   b  on both sides of the bottom case  2   b . The side keys  12   b  are trigger keys for RFID reading/writing. 
     Next, the functional configuration of the handy terminal  1  will be explained with reference to  FIG. 2 . The respective constituting elements in  FIG. 2  are mounted on the substrate  10  and connected to each other. 
     As shown in  FIG. 2 , the handy terminal  1  includes a CPU (central processing unit)  11 , operation unit  12 , RAM (random access memory)  13 , display unit  14 , ROM (read only memory)  15 , patch antenna  30 , loop antenna  40 , a GPS communication unit  16  as a first communication unit, a RFID communication unit  17  as a second communication unit, storage unit  18 , and an imaging unit  19 . 
     The respective units of the handy terminal  1  are connected by a bus  20 . An antenna device ANT has the patch antenna  30  and the loop antenna  40 . 
     The CPU  11  controls the respective units of the handy terminal  1 . The CPU  11  reads designated system programs and application programs stored in the ROM  15  and executes various types of processes in cooperation with these programs. 
     The operation unit  12  has the keys  12   a  and the side keys  12   b , which respectively receive push input from the user. The operation information from this push input is outputted to the CPU  11 . The operation unit  12  may include a touch panel integrally formed with the display unit  14 . 
     The RAM  13  is a volatile memory that has a work area for temporarily storing various types of data and programs. The display unit  14  performs various types of display in accordance with display information received from the CPU  11 . The ROM  15  is a read-only memory that stores various types of data and programs. 
     The patch antenna  30  is a receiver antenna for GPS radio waves, and has a resonant frequency f 1  of 1.5754 GHz. The GPS communication unit  16  is a reception unit that receives GPS radio waves from the GPS satellites through the patch antenna  30  and obtains the GPS signals in these GPS radio waves. 
     The GPS communication unit  16  has a GPS reception circuit  16   a.    
     The GPS reception circuit  16   a  processes GPS radio wave-induced antenna current received from the patch antenna  30 , and has a demodulating circuit, amp, signal processing circuit, and the like. 
     The CPU  11  calculates longitudinal and latitudinal position information of the handy terminal  1  in accordance with the GPS signals received from the GPS communication unit  16  via the patch antenna  30 . The CPU  11  detects positions in accordance with these calculations. 
     The loop antenna  40  is a coil antenna for RFID communication and has a resonant frequency f 2  of 13.56 MHz. 
     The RFID communication unit  17  performs short-range communication with RFID tags, RFID IC cards, and the like. 
     The RFID communication unit  17  has an RFID driver circuit  17   a.    
     The RFID driver circuit  17   a  generates antenna current to be sent to the loop antenna  40  and processes antenna current received from the loop antenna  40 . The RFID driver circuit  17   a  has a modulation/demodulation circuit, amp, signal processing circuit, and the like. 
     When reading RFID tags etc., the CPU  11  instructs the RFID communication unit  17  to communicate with the RFID tags etc. via the loop antenna  40  and receive the information stored in these RFID tags etc. 
     When writing information to the RFID tags etc., the CPU  11  causes the RFID communication unit  17  to send the information to the RFID tags etc. and causes this information to be stored. 
     The storage unit  18  is a readable/writable memory constituted of a flash memory, EEPROM (electrically erasable programmable read only memory), or the like. 
     The imaging unit  19  performs imaging and outputs image data in accordance with instructions from the CPU  11 . When reading symbols, i.e., the objects of image capture, the imaging unit  19  captures the image of the symbols and generates image data, which the CPU  11  decodes to obtain the information included in the symbols. 
     The handy terminal  1  may be provided with other antennas and communication units. The handy terminal  1  may include wireless LAN (local area network) and portable mobile communication antennas and communication units or the like, for example. 
     Next, the configuration of the patch antenna  30  will be explained using  FIG. 3 . 
     For simplicity of explanation, the patch antenna  30  and the loop antenna  40  in  FIGS. 3 to 5  are shown with an abbreviated shape. The actual shapes of the patch antenna  30  and the loop antenna  40  are shown in  FIGS. 8A and 8B . 
     The patch antenna  30  includes a surface electrode  31 , ground electrode  32 , body section  33 , and a power supply terminal  34 . The surface electrode  31  is a conductor such as silver patterning formed on the top of the body section  33 . 
     The ground electrode  32  is a conductive surface electrode such as copper foil disposed on the bottom of the body section  33 . The ground electrode  32  is grounded. The body section  33  is constituted of a dielectric or the like, and has a cuboid shape, for example. The power supply terminal  34  is a conductor that is electrically connected to the surface electrode  31  and disposed so as to penetrate the body section  33 . The GPS reception circuit  16   a  is connected to the ground electrode  32  and the power supply terminal  34 . 
     In  FIG. 3 , the direction perpendicular to the surface electrode  31  (the direction above the patch antenna  30 ) is the Z axis, the direction parallel to one side (here, in the lengthwise direction) of the top of the patch antenna  30  is the X axis, and the direction parallel to the other side (in the widthwise direction) of the top of the patch antenna  30  and perpendicular to the X axis is the Y axis. A directionality  30 A of the patch antenna  30  is represented by two directions in the ±Z direction. 
     Next, the configuration of the loop antenna  40  will be explained using  FIG. 4 . 
     The loop antenna  40  has a conductor part  41 . The conductor part  41  is constituted of a conductive (copper foil) pattern formed on an insulating film (not shown). 
     The configuration of the conductor part  41 , however, is not limited to a conductive pattern on an insulating film, and may be wound lead wiring, for example. The RFID driver circuit  17   a  is connected to two conductor terminals of the conductor part  41 . 
     The loop antenna  40  has a loop shape (coil shape) wounded three turns in a substantially rectangular shape, for example. The number of turns that the conductor part  41  is wounded, however, is configured so as to be optimal for RFID magnetism, and thus is not limited to three turns. 
     In  FIG. 4 , the axis direction of the loop portion of the conductor part  41  is the Z axis, the direction parallel to one side (here, in the lengthwise direction) of the conductor part  41  is the X axis, and the direction parallel to the other side (in the widthwise direction) of the conductor part  41  and perpendicular to the X axis is the Y axis. A directionality  40 B of the loop antenna  40  is represented by the ±X direction and ±Y direction (i.e., four directions) respectively perpendicular to the four sides of the loop portion of the conductor part  41 . 
     Due to the directionality of the loop antenna  40 , there is no dependency on the polarization plane of the radio waves, and thus radio waves can be picked up from both vertically polarized waves and horizontally polarized waves. Radio waves can also be picked up from circularly polarized waves, in which the polarization plane rotates. 
     The line length of one loop of the conductor part  41  is loop length  41 L. The loop length  41 L is set to one wavelength λ 1  of the GPS radio waves. The resonant frequency f 1  of the GPS radio waves is 1.5754 GHz; therefore, loop length  41 L=c/f 1 =0.1904 m. 
     By making the loop length  41 L correspond to one wavelength λ 1  of the GPS radio waves, standing waves can be caused to be generated at the conductor (element) at the frequency of the GPS radio waves, in a manner similar to a dipole antenna or the like, thereby generating an electric field. 
     Therefore, the loop antenna  40  can effectively pick up GPS radio waves that are right-handed circularly polarized waves by the above-mentioned loop length  41 L and the directionality. 
     Next, magnetic coupling of the patch antenna  30  and the loop antenna  40  will be explained with reference to  FIGS. 5 and 6 . 
       FIG. 5  is a perspective view of magnetic coupling when the patch antenna  30  receives GPS radio waves W 1 . 
       FIG. 6  is a perspective view of magnetic coupling when the loop antenna  40  receives GPS radio waves W 2 . 
     An arrangement will be considered in which the direction (Z direction in  FIG. 3 ) perpendicular to the surface electrode  31  of the patch antenna is parallel to the axis direction (Z direction in  FIG. 4 ) of the loop portion of the loop antenna  40 , and the patch antenna  30  and the loop antenna  40  are arranged adjacent to each other. 
     As shown in  FIG. 5 , a situation is illustrated in which the patch antenna  30  receives the GPS radio waves W 1  from the +Z direction corresponding to the directionality  30 A of the patch antenna  30 . 
     The patch antenna  30 , which is resonating at the frequency (1.5754 GHz) of the GPS radio waves W 1 , generates a magnetic field B 1 . The loop portion of the loop antenna  40  is disposed in this generated magnetic field B 1  so as to cause the patch antenna  30  and the loop antenna  40  to become magnetically coupled. The magnetic field B 1  causes antenna current I 1  to flow to the conductor part  41 . The antenna current generated by the patch antenna  30  receiving the GPS waves is sent to the GPS reception circuit  16   a.    
     Next, as shown in  FIG. 6 , the loop antenna  40  receives the GPS waves W 2  from the +X direction, −X direction, +Y direction, or −Y direction corresponding to the directionality  40 B of the loop antenna  40 . 
     The loop antenna  40  receives the GPS waves W 2  and generates standing waves in accordance with the loop length  41 L at the conductor part  41 , which causes antenna current I 2  to flow and a magnetic field B 2  to be generated. The resonant frequency f 2  of the loop antenna  40 , however, is 13.56 MHz; therefore, there will be no resonance even if the loop antenna  40  receives the GPS waves W 2 . 
     The patch antenna  30  is disposed in a position that magnetically couples with the loop antenna  40  when the GPS waves are received. In other words, the patch antenna  30  is placed in the magnetic field B 2  generated by the loop antenna  40 . The patch antenna  30  and the loop antenna  40  become magnetically coupled to each other, and thus, after the patch antenna and loop antenna are coupled, the magnetic field B 2  arrives at the GPS reception circuit  16   a  as antenna current via the patch antenna  30 . 
     In this manner, the loop antenna  40  also functions as a reception antenna for GPS radio waves. Therefore, the patch antenna  30  and the loop antenna  40  can receive GPS radio waves from the +Z direction, ±X direction, or ±Y direction. 
     Next, a resonant circuit and equivalent circuit of the loop antenna  40  will be explained with reference to  FIGS. 7A and 7B . 
       FIG. 7A  is a resonant circuit  50   a  of the loop antenna  40 . 
       FIG. 7B  is an equivalent circuit  50   b  of the loop antenna  40  and the RFID driver circuit  17   a.    
     The loop antenna  40  resonates due to an RFID electromagnetic field (radio waves). As shown in  FIG. 7A , the resonant circuit  50   a  of the loop antenna  40  has a configuration in which a coil L 1  corresponding to the loop antenna  40  and a capacitor C 1  are connected in series. The resonant circuit  50   a , which is an LC circuit, resonates at the electromagnetic frequency of the RFID, 13.56 MHz, and at this time serial impedance Z is 0Ω. 
     Calculation examples for the capacitor C 1  in an ordinary RFID circuit will be explained below. In general, an impedance L of a three turn coil is approximately lnH. In order to make this coil resonate at a frequency of 13.56 MHz, a capacitance C of the capacitor C 1  is calculated as 0.138 μF in formula (1) below.
 
1/(2 π√LC )=resonant frequency  (1)
 
     The circuit shown in  FIG. 7B  is the equivalent circuit  50   b  of the loop antenna  40  and the RFID driver circuit  17   a . The equivalent circuit  50   b  has a power source  17 E, and the coil L 1  and capacitor C 1 , which are connected in parallel to the power source  17 E. The power source  17 E and the capacitor C 1  are the equivalent circuit of the RFID driver circuit  17   a . The equivalent circuit  50   b  resonates by generating a current corresponding to a frequency of 13.56 MHz from the power source  17 E. The impedance Z is 0. 
     The qualify factor of the resonant circuit  50   a  for the resonance frequency f 1  and the resonant frequency f 2  will be considered below. The Q factor must be small when attempting to induce antenna current at a frequency that is broad enough to both cause the loop antenna  40  to resonate at the resonant frequency f 2 , thereby inducing antenna current, and to cause antenna current to be induced in the loop antenna  40  at the resonant frequency f 1 , as in the present embodiment. If the impedance of the coil L 1  is lnH, the capacity of the capacitor C 1  is 0.138 μF, and the pure resistance of the conductor is 1Ω, then Q will be 0.0851 or a similarly small value. 
     Furthermore, during reception of radio waves at the resonant frequency f 1 , there will be demand for the impedance of the loop antenna  40  to be low enough to allow the antenna current, which is induced by the standing waves generated by the loop length  41 L, to flow. In the resonant circuit  50   a , the impedance Z when inducing a current corresponding to 1.575 GHz is calculated as 9.89Ω in accordance with the formula jωL+(1/jωC). The value of this impedance Z will not hinder antenna current that will generates standing waves in the loop antenna  40 . 
     Next, the antenna directionality of the handy terminal  1  caused by the patch antenna  30  and the loop antenna  40  will be explained with reference to  FIGS. 8A and 8B . 
       FIG. 8A  is a perspective view of the directionality generated by the patch antenna  30  and the loop antenna  40  attached to the substrate  10 . 
       FIG. 8B  is a plan view of the directionality generated by the patch antenna  30  and the loop antenna  40 . 
     As shown in  FIG. 8A , the patch antenna  30  and the loop antenna  40  are attached to the tip of the substrate  10  of the handy terminal  1 . The patch antenna  30  is disposed such that the direction perpendicular to the surface electrode is the Z direction. The loop antenna  40  is disposed such that the axis direction of the loop portion is the Z direction. The loop antenna  40  is disposed such that the imaging unit  19  is positioned in the empty portion in the center of the loop. 
     As shown in  FIGS. 8A and 8B , the patch antenna  30  has the directionality  30 A in the ±Z direction, as explained in  FIG. 3 . The loop antenna  40  has the directionality  40 B in the ±X direction and the ±Y direction. The loop antenna  40  magnetically couples with the patch antenna  30  when the loop antenna  40  receives GPS radio waves, which causes antenna current to be sent to the GPS reception circuit  16   a  through the patch antenna  30 . 
     In accordance with this principle, the handy terminal  1  can combine the directionality  30 A of the patch antenna  30  and the directionality  40 B of the loop antenna  40  with respect to GPS radio waves, and has directionalities  30 A and  40 B in all directions unobstructed by the substrate  10 : the +Z direction, the ±X direction, and the ±Y direction. 
     The GPS satellites are located in the zenith direction of the earth. Therefore, GPS radio waves can be received even when facing the direction of the tip of the handy terminal  1  (+Z direction, the direction perpendicular to the plane of the case (top case  2   a , bottom case  2   b ) (±Y direction), or the direction perpendicular to the sides of the case (±Y direction). 
     According to the present embodiment, the handy terminal  1  includes the patch antenna  30 , which has a resonant frequency f 1  that is a frequency for GPS communication, and the loop antenna  40 , which has a resonant frequency f 2  that is a frequency for RFID communication. The loop length  41 L of the loop antenna  40  is long enough to generate standing waves when the loop antenna  40  receives GPS radio waves. The patch antenna  30  is disposed in a position that magnetically couples with the loop antenna  40 . 
     Therefore, the patch antenna  30  and the loop antenna  40  can be arranged close enough to magnetically couple with each other, the directionality of the patch antenna  30  can be combined with the directionality of the loop antenna  40  with respect to GPS radio waves, and the handy terminal can have directionality that corresponds to many directions, thereby making it possible to increase antenna performance. 
     Furthermore, the patch antenna  30  and the loop antenna  40  can be made to function after being caused to magnetically couple with each other, thereby making it possible to operate the two antennas, which is not possible with conventional configurations that place the antennas adjacent to each other, and allowing for the antennas inside the handy terminal  1  to be made smaller (denser). The loop length  41 L allows for generation of standing waves even without a resonant circuit, which allows for high sensitivity. 
     In addition, because the loop antenna  40  magnetically couples with the patch antenna  30 , the GPS reception circuit  16   a  does not strictly require wiring or circuits for GPS use, and GPS radio waves can be received with a simple structure. 
     The loop length  41 L is one wavelength λ 1  of GPS radio waves. Thus, the loop antenna  40  can have a suitable size that corresponds to the handy terminal  1   
     The patch antenna  30  and the loop antenna  40  are also arranged in a positional relationship whereby the Z direction, which is parallel to the surface electrode  31  of the patch antenna  30 , is parallel to the axis direction of the loop antenna  40 . This makes it possible to obtain directionality in the +Z direction, the ±X direction, and the ±Y direction. 
     Furthermore, the resonant frequency of the patch antenna  30  is a frequency for GPS communication, and the resonant frequency of the loop antenna  40  is a frequency for RFID communication. Thus, it is possible to perform RFID communication using the loop antenna  40 , and to receive GPS radio waves emitted from the GPS satellites regardless of whichever direction the antenna device ANT (handy terminal) is facing. 
     Modification Example 
     A modification example of the above-mentioned embodiment will be explained using  FIG. 9 .  FIG. 9  is a plan view of the patch antenna  30  and a loop antenna  40   c.    
     The shape of the loop antenna  40  in the above-mentioned embodiment was configured in accordance with attachment point (substrate  10 , imaging unit  19 , etc.), the shape of the patch antenna  30 , the attachment space, and the like. 
     As shown in  FIG. 8A , the patch antenna  30  has, on the loop antenna  40  side thereof, a first patch antenna side that extends in the widthwise direction of the top of the patch antenna  30  (the surface perpendicular to the Z direction), and a second patch antenna side that extends in the lengthwise direction of the patch antenna. The first patch antenna side and the second patch antenna side are adjacent to each other. 
     The loop antenna  40  has a first loop antenna side adjacent to the patch antenna  30  and extending in the Y direction, and a second loop antenna side that is adjacent to the patch antenna and that extends in the X direction. The first patch antenna side is longer than the first loop antenna side, and the first patch antenna side and the first loop antenna side only partially face each other. 
     The second patch antenna side is longer than the second loop antenna side, and the second patch antenna side and the second loop antenna side only partially face each other. 
     Therefore, the patch antenna  30  and the loop antenna  40  cause magnetic coupling primarily between the second patch antenna side and the second loop antenna side, which makes it possible to cause a significant amount of magnetic coupling, thereby allowing for antenna performance to be increased. 
     The handy terminal  1  of the present modification example does not have an imaging unit, has no constraints on the attachment space for the loop antenna, etc. Therefore, as shown in  FIG. 9 , the handy terminal  1  has the loop antenna  40   c  instead of the loop antenna  40 . 
     The two adjacent sides on a top  30   c  of the patch antenna  30  are the sides  301  and  302 . The length of the side  301  is length  301 L. The length of the side  302  is length  302 L. The loop antenna  40   c  has an “L”-loop shaped conductor part  41   c . The loop length of the conductor part  41   c  is the same as the loop length  41 L. 
     The conductor part  41   c  has sides  401  and  402  that are adjacent to each other. The length of the side  401  is length  401 L. The length of the side  402  is length  402 L. The side  401  is adjacent and parallel to the side  301  of the patch antenna  30 . The length  401 L is configured so as to be longer than the length  301 L. 
     The side  301  is arranged so as to be within the length  401 L of the side  401 . The side  402  is adjacent and parallel to the side  302  of the patch antenna  30 . The length  402 L is configured so as to be longer than the length  302 L. The side  302  is arranged so as to be within the length  401 L of the side  402 . 
     As shown by the elliptical portions in  FIG. 9 , magnetic coupling is generated between the side  301  and the side  401  and between the side  302  and the side  402 . Therefore, the magnetic field generated when the loop antenna  40   c  receives GPS radio waves is more effectively transmitted to the patch antenna  30  than the magnetic field of the loop antenna  40 . 
     Thus, the magnetic coupling of the patch antenna  30  and the loop antenna  40   c  is stronger than the magnetic coupling of the patch antenna  30  and the loop antenna  40 . 
     According to the modification example described above, the loop antenna  40   c  has the side  401 , which is longer than the length  301 L of the side  301  of the top  30   c  of the patch antenna  30  and which is adjacent and parallel to this side  301 , and the side  402 , which is longer than the length  302 L of the side adjacent to the side  301  and which is adjacent and parallel to this side  302 . Therefore, it is possible to make the magnetic coupling of the patch antenna  30  and the loop antenna  40   c  stronger than the magnetic coupling of the patch antenna  30  and the loop antenna  40 , which allows for the generated magnetic fields to be efficiently picked up by the patch antenna  30  when GPS radio waves are received by the loop antenna  40   c.    
     The descriptions of the above-mentioned embodiment and the modification example above is one example of an antenna device and a portable electronic device according to one aspect of the present invention, and the present invention is not limited to this. 
     In the above-mentioned embodiment and modification example, the handy terminal  1  was the portable electronic device, but the present invention is not limited to this, for example. 
     A smartphone, PDA (personal digital assistant), or other device may be used as the portable electronic device. 
     Furthermore, in the above-mentioned embodiment and modification example, the resonant frequency of the patch antenna  30  was a frequency used for GPS communication, and the resonant frequency of the loop antenna  40  and  40   c  was a frequency used for RFID communication, but the present invention is not limited to this. 
     The resonant frequency (first frequency) of the patch antenna and the resonant frequency (second frequency) of the loop antenna may be a different frequency. 
     The patch antenna may be an antenna for a wireless LAN communication scheme while the loop antenna is for RFID use, and the first frequency may be 2.4 GHz (band) for wireless LAN communication. Even with this configuration, the directionality of the antenna for wireless LAN communication can be broadened. 
     The impedance of the loop antenna during reception of radio waves in the first frequency, however, should be low enough to allow antenna current caused by stationary waves generated by the loop length to flow. It is necessary for the Q factor of the loop antenna to be lowered in order to allow antenna current to flow to the loop antenna within the first frequency and the second frequency. 
     In the embodiment and the modification example described above, the loop length  41 L of the loop antennas  40  and  40   c  is one wavelength of the resonant frequency of the patch antenna  30 , but the present invention is not limited to this. In accordance with installation space and the like for the patch antenna and the loop antenna, the loop length of the loop antenna may be n times or ½ m times (n, m: integers) the wavelength λ 1  of the resonant frequency of the patch antenna  30 , or preferably ½ times or ¼ times the wavelength λ 1 . 
     The detailed configuration and operation of the respective constituting elements of the handy terminal  1  in the above-mentioned embodiment and modification example can be modified as appropriate without departing from the spirit of the invention. 
     An embodiment and modification example of the present invention were described above, but the scope of the present invention is not limited to the above-mentioned embodiment and modification example, and includes the claims of the invention and equivalent claims thereof described in the section of the claims. In particular, it is explicitly contemplated that any part or whole of any two or more of the embodiments and their modifications described above can be combined and regarded within the scope of the present invention.