JP4715757B2 - Communications system - Google Patents

Description

  In the present invention, an electromagnetic wave radiated from a communication base station such as a radar or RF-ID (Radio Frequency Identification) is scattered by an unspecified object or a terminal station and arrives at the base station again. The present invention relates to a communication system that a station receives and identifies unspecified objects or information unique to a terminal station.

  The technology for remotely identifying an unspecified number of objects is expected to be useful in abundance in recent years as the quantity of physical distribution increases and the distribution speed increases. In order to identify objects in such a large amount and at high speed, it is indispensable to apply information transmission means that infiltrate the objects because the positional relationship between these objects cannot be specified. Wireless technology is suitable for such applications, and in particular, a system for detecting an object using electromagnetic waves and a system for transmitting information held by the object have already been realized, for example, as a radar system or a wireless tag system. I am serving.

  However, with the increase in logistics speed and capacity, it has become a universal social requirement to improve the ability of object detection and information transmission using electromagnetic waves, in other words, the distance that electromagnetic waves can reach in the system. Yes. The electromagnetic wave attenuates in proportion to the distance to the power of 2 to 3 along with the transmission distance. Therefore, when the transmission distance of the electromagnetic wave increases, when the electromagnetic wave radiated from the base station arrives at the base station again, its power decreases remarkably. Therefore, it is extremely resistant to various disturbance factors. In such a system, in order to re-radiate the energy of the electromagnetic wave arriving from the base station to the base station with as little conversion loss as possible, generally a method of using the scattered electromagnetic field itself from the object to be identified as a carrier wave for information transmission Is common. In order to generate a new carrier wave by some means, it is necessary to convert the high-frequency power of the electromagnetic wave into power supply power for some means, and in that case, a conversion loss always occurs in reality. In wireless transmission using electromagnetic waves, the reach of electromagnetic waves is limited by the power to be applied to the carrier, so maximizing the power efficiency of carrier generation is the reach of electromagnetic waves in the system, in other words, the application limit of the system Leads to maximizing

  In a system that uses scattered waves directly as a carrier wave, the transmission power itself radiated from the base station is the largest disturbance factor of the electromagnetic waves that re-enter the base station. This is because the disturbance factor cannot be removed using a general-purpose technique such as a filter because the frequencies of both are the same. In general, in a radio communication system, frequency division duplex (frequency division duplex: FDD) or time division duplex (time division duplex: TDD) is used to duplex a transmission wave and a reception wave (duplex). A technique called reception and transmission at different frequencies or different time timings, which is equivalently duplexed between a transmission wave and a reception wave, is used. In the case of using a scattered wave directly as a carrier wave, a conventional technique that can be called direction division duplex (DDD) is known. In this technique, a circulator is used to exit from a base station. The transmission wave and the reception wave are equivalently duplicated by using the difference in directionality between the electromagnetic wave and the electromagnetic wave entering the base station (see, for example, Non-Patent Document 1).

  FIG. 14 is a circuit diagram showing a configuration of a conventional communication base station. As shown in FIG. 14, the communication base station includes a carrier wave generator 61 that is a source of electromagnetic waves, an antenna 68 that radiates the electromagnetic waves to the outside (for example, toward the terminal station), and a received wave at the antenna 68. A receiving circuit 62 for receiving, a carrier wave generator 61, an antenna 68, and a circulator 64 for connecting the receiving circuit 62 are provided.

  In the communication base station of FIG. 14, a circulator 64 is used as a directional coupler, and an electromagnetic wave generated by the carrier wave generator 61 is radiated from an antenna 68 via the circulator 64. The electromagnetic wave rearriving at the base station is guided from the antenna 68 to the circulator 64 and is transmitted not to the carrier wave generator 61 but to the receiving circuit 62 due to the nonreciprocity of the circulator 64.

JP 2006-203469 A Klaus Finkenzellar, Translated by Software Engineering Laboratory "RFID Handbook 2nd Edition", May 2004, Nikkan Kogyo Shimbun, p. 45

  However, according to the conventional communication base station, in the circulator 64, electromagnetic energy wraparound in the reverse rotation direction, which cannot be generated in principle, actually occurs at about -20 to -30 dB. On the other hand, as the distance between the base station and the target object or between the base station and the terminal station increases, the electromagnetic wave re-arriving at the base station attenuates in proportion to the power of the distance to the second to third power and becomes weak. There is a problem that the degree of transmission wave (noise) from the device 61 to the receiving circuit 62 via the circulator 64 increases, and the distance between the base station and the target object or the base station and the terminal station cannot be increased. there were.

  Accordingly, an object of the present invention is to solve the above-described problems and suppress the electromagnetic wave itself generated at the base station from becoming a disturbance to the electromagnetic wave rearriving at the base station. As a result, the base station and the target object or terminal station It is an object of the present invention to provide a communication system that makes it possible to take a large distance.

To achieve the above object, the present invention is a communication system including a base station and a terminal station, the base station comprises a transmitting circuit and the receiving circuit, the transmission circuit a first base station 90 ° bind to port 1 of the hybrid coupler, the first base station 90 ° port 2 of the hybrid coupler are terminated by a resistor above the ports 3 and 4 of the first base station 90 ° hybrid coupler respectively first And the first circulator port 1 is coupled, and the first and second circulator ports 2 are coupled to the first and second base station circularly polarized antennas having different swirl polarization directions, respectively. Port 1 and port 2 of the second base station 90 ° hybrid coupler are coupled to port 3 of the first and second circulators, respectively, and port 3 of the second base station 90 ° hybrid coupler is connected. Is terminated with the resistor, the second the receiver circuit to the port 4 of the base station 90 ° hybrid coupler are combined, and the terminal station a first and a second terminal station circular polarization each of the turning direction of polarization different The terminal station 90 ° hybrid coupler port 3 and port 4 are coupled to the first and second terminal station circularly polarized antennas, and the terminal station 90 ° hybrid coupler port 2 is terminated with a resistor. A modulator is coupled to port 1 of the terminal station 90 ° hybrid coupler.

  The modulator may switch an input impedance of the antenna.

  The transmission circuit may be a carrier wave generation circuit.

The base station is formed using a single multilayer board, components other than the base station circular polarization antenna is mounted on the surface of the multilayer substrate, two base stations circular polarization turning the polarization direction are different An antenna may be mounted on the back surface of the multilayer substrate. The two base station circularly polarized antennas may be realized by a series of plane structures including two feeding points.

The terminal station is formed using a single multilayer board, components other than the terminal station circular polarization antenna is mounted on the surface of the multilayer substrate, two terminal stations circular polarization turning the polarization direction are different antenna may be mounted on the rear surface of the multilayer substrate.

The two terminal-station circularly polarized antennas may be realized by a series of plane structures including two feeding points.

The terminal station comprises a rectifier circuit and a microprocessor with memory circuits and the changeover switch, the rectifier circuit energy of the input electromagnetic wave from the two terminal station circular polarization antenna is supplied to the microprocessor, the microsensor The processor may switch the input impedances of the two terminal-station circularly polarized antennas by turning on / off the change-over switch according to a certain rule based on information stored in the storage circuit.

  There may be a plurality of the terminal stations, and the transmission timings of the modulation signals transmitted by the terminal stations may be different from each other.

According to the above configuration, square using countercurrent division duplex circularly polarized wave antenna pairwise with different turning the polarization direction of the leakage of the transmission power to the reception circuit which generates through the circulator base station faced by Therefore, the distance between the base station and the target object or the terminal station can be increased.

  According to the present invention, since the disturbance due to the transmission wave of the base station itself can be greatly suppressed with respect to the reception wave received by the base station antenna, the signal-to-noise ratio of the information contained in the reception wave can be improved. it can. As a result, it is possible to increase the distance between the base station and the target object or the terminal station, and the excellent effect of expanding the application range (region) of the communication system having the communication base station is exhibited.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

FIG. 1 is a circuit diagram showing a configuration of a communication system (polarization division duplex PDD communication system) according to a first embodiment of the present invention.
As shown in FIG. 1, the communication system includes a base station (BS in the figure) 10 and a terminal station (TS in the figure) 20.

  The base station 10 includes a transmitting circuit 1, a receiving circuit 2, a base station in-phase two distributor 3 and a 180-degree phase shifter 4, which is a combination of a base station anti-phase two distributor, a first circulator 5, and a second circulator. 6. A first base station circular polarization antenna 7 and a second base station circular polarization antenna 8 are provided.

  The input of the transmission circuit 1 is coupled to the input port of the base station in-phase bi-distributor 3, and the first output and the second output of the base station in-phase bi-distributor 3 are shifted to the ports 1 and 180 of the first circulator 5, respectively. A port 1 of the second circulator 6 via the phaser 4 is coupled, and the first base station circularly polarized antenna 7 and the second circulator having different rotational polarization directions are connected to the ports 2 of the first and second circulators. A second base station circularly polarized antenna 8 is coupled, and the first and second input ports of the base station in-phase two combiner 9 are coupled to the port 3 of the first and second circulators. The receiving circuit 2 is coupled to the output port of the in-phase two synthesizer.

  The terminal station 20 includes a terminal 21, an in-phase two synthesizer 23, and a 180-degree phase shifter 24 connected to (or a combination of) a terminal station anti-phase two-distribution coupling means, and a first terminal. A local circularly polarized antenna 27 and a second terminal circularly polarized antenna 28 are provided.

  The first terminal station circularly polarized antenna 27 and the second terminal station circularly polarized antenna 28 having different swirl polarization directions have a first input port and a 180 degree phase shifter of the terminal station in-phase / two-synthesizer 23, respectively. The second input port via 24 is coupled, and the modulator 21 is coupled to the output port of the terminal station in-phase two-synthesizer 23.

  The operation of the communication system of the present embodiment will be described.

  The electromagnetic wave (transmission wave signal) output from the transmission circuit 1 is distributed into two transmission waves (signals) in phase with each other by the base station in-phase two distributor 3. One of the transmitted waves is radiated from the first base station circularly polarized antenna 7 to the external space via the first circulator 5. The other of the transmitted waves has its phase changed by 180 degrees (π / 2) by the second circulator 6 and the 180-degree phase shifter 4 and is radiated from the second base station circularly polarized antenna 8 to the external space. That is, the transmitted waves radiated from both base station circularly polarized antennas 7 and 8 are radiated with almost no loss at different polarizations (reverse phases). Actually, loss is caused by copper loss, iron loss, radiation loss, etc. of each element, but it is about -1 dB or less, which is not a problem in practice.

  On the other hand, the electromagnetic waves input from the first base station circularly polarized antenna 7 and the second base station circularly polarized antenna 8 are respectively transmitted to the base station in-phase two-synthesizer 9 via the first and second circulators 5 and 6. Are combined in phase and transmitted to the receiving circuit 2 with almost no loss.

  Here, in the base station 10, a part of the power output from the transmission circuit 1 and distributed in two by the base station in-phase two distributor 3 is reversely rotated (received) in the first circulator 5 and the second circulator 6. Leak (turn around) in the direction of circuit 2). However, in the present embodiment, the electromagnetic wave that leaks in the second circulator 6 is out of phase with the electromagnetic wave that leaks in the first circulator 5 due to the action of the 180-degree phase shifter 4. Accordingly, electromagnetic waves having opposite phases to each other are combined by the base station in-phase two synthesizer 9 and are canceled out, and hardly reach the receiving circuit 2.

  The terminal station 20 receives electromagnetic waves (reception waves) having different polarizations from the first terminal station circular polarization antenna 27 and the second terminal station circular polarization antenna 28, respectively. The received electromagnetic waves have opposite phases, but the electromagnetic wave received by the second terminal station circularly polarized antenna 28 is phase-shifted by the 180-degree phase shifter 24. Therefore, the two electromagnetic waves are in phase with each other, and these electromagnetic waves are synthesized in phase by the terminal station in-phase two synthesizer 23 and transmitted to the modulator 21.

  Conversely, the electromagnetic wave transmitted from the modulator 21 passes through the above-mentioned path in the reverse direction, and electromagnetic waves having different polarizations are radiated from the first and second terminal station circularly polarized antennas 27 and 28.

  A pair of circularly polarized antennas having different swirl polarization directions of the base station 10 and the terminal station 20 exhibit high isolation characteristics due to the orthogonality of the polarization of electromagnetic waves. Actually, some leakage occurs between the antennas due to an antenna manufacturing error or the like, but the leakage can be canceled out by the same principle as described above.

  Therefore, according to the communication system of the present embodiment, leakage of transmission power to the receiving circuit generated via the circulator of the base station that the conventional direction division duplex system has has two different circular polarization directions. Since it can be suppressed by using a pair of circularly polarized antennas, signal-to-noise is improved, and the distance between the base station and the target object or terminal station is increased.

  Next, a second preferred embodiment according to the present invention will be described with reference to FIG.

  As shown in FIG. 2, the communication system of this embodiment includes a combination of the base station in-phase two distributor 3 and the 180-degree phase shifter 4 and the terminal station in-phase two synthesizer 23 and the 180-degree phase shifter 24 shown in FIG. 1 is different from the communication system of FIG. 1 in that the combination of is replaced with a base station rat race circuit 13 and a terminal station rat race circuit 33 that perform equivalent operations.

  In the base station rat race circuit 13, the electromagnetic waves (transmission waves) input from the transmission circuit 1 are output from the first circulator 5 and the second circulator 6, respectively. Since the electrical length from the transmission circuit 1 side to each output port (the first circulator 5 side and the second circulator 6 side) is ½ wavelength different, the distributed electromagnetic waves are out of phase with each other.

  Next, a third embodiment will be described based on FIG.

  As shown in FIG. 3, in this embodiment, in the communication system of the second embodiment, the base station in-phase two combiner 9 of the base station 10 is replaced with 14 Wilkinson two combining circuits.

  The Wilkinson two-synthesizing circuit 14 synthesizes two input electromagnetic waves in phase, as in the base station in-phase two synthesizer 9 of FIG.

  In this embodiment, since the in-phase two synthesizer 9 is replaced with a Wilkinson two synthesizer circuit 14 that can be realized with a simple circuit configuration, it is effective in reducing the size of the base station and terminal station of the communication system.

  An example of the communication system according to this embodiment will be described. FIG. 4 shows the structure of the base station 10 of FIG. 3, and FIG. 5 is a transparent perspective view showing the structure of the terminal station 20 of FIG.

  As shown in FIG. 4, the base station includes a multilayer substrate having a three-layer structure of a surface layer 101, an intermediate ground layer 105, and a back layer 102. A first dielectric layer 103 is formed between the surface layer 101 and the intermediate ground layer 105, a second dielectric layer 104 is formed between the back layer 102 and the intermediate ground layer 105, and the first dielectric layer 103 is formed on the back layer 102. A base station circularly polarized antenna 47 and a second base station circularly polarized antenna 48 are formed. The surface layer 101 has a transmission circuit 41, a base station rat race circuit 43, a termination resistor 59, a first circulator 45, and a second circulator 45. A circulator 46, a Wilkinson two synthesis circuit 44, and a reception circuit 42 are formed. Transmitter circuit 41, receiver circuit 42, first and second circulators 45 and 46, base station rat race circuit 43, Wilkinson two synthesis circuit 44, termination resistor 59, first and second base station circularly polarized antenna 47, The electrical connection relationship of 48 is the same as that of the base station of FIG. One end of the terminating resistor 59 is electrically coupled to the intermediate ground layer 105 through the through-hole 114, and the electrical coupling between the first and second circulators and the first and second base station circularly polarized antennas is determined by the intermediate ground layer. The through-hole 115 provided in the layer 105 is contactlessly penetrated and is formed by the second through-hole 116.

  Further, as shown in FIG. 5, the terminal station is composed of a multilayer substrate having a three-layer structure of a surface layer 101, an intermediate ground layer 105, and a back layer 102, and the first layer is between the surface layer 101 and the intermediate ground layer 105. A dielectric layer 103 is formed, a second dielectric layer 104 is formed between the back layer 102 and the intermediate ground layer 105, and the first terminal station circularly polarized antenna 67 and the second terminal station are formed on the back layer 102. A circularly polarized antenna 68 is formed, and a modulation circuit 61, a terminal station rat race circuit 73, and a termination resistor 69 are formed on the surface layer 101. The electrical connection relationship of the modulation circuit 61, the terminal station rat race circuit 73, the termination resistor 69, and the first and second terminal station circularly polarized antennas 67 and 68 is the same as that of the terminal station 20 of FIG. One end of the terminating resistor 69 is electrically coupled to the intermediate ground layer 105 through the through-hole 114, and electrical coupling between the terminal station rat race circuit and the first and second base station circularly polarized antennas is performed by the intermediate ground layer 105. The second through hole 116 is formed in a non-contact manner through the through hole 115 provided in the second through hole 116.

  According to the present embodiment, the base station 10 and the terminal station 20 of the embodiment of FIG. 3 can be formed with an integrated thin plate structure using a general-purpose printed multilayer board process, and can be realized in a small size and at low cost.

  Next, a fourth embodiment will be described based on FIG.

  As shown in FIG. 6, the communication system according to the present embodiment includes a base station 10 and a terminal station 20, and the base station 10 includes a transmission circuit 1, a reception circuit 2, a first base station 90 ° hybrid coupler 15. A second base station 90 ° hybrid coupler 16, a first circulator 5, a second circulator 6, a first base station circularly polarized antenna 7 and a second base station circularly polarized antenna 8, 20 includes a modulator 21, a terminal station 90 ° hybrid coupler 35, a first terminal station circular polarization antenna 27, and a second terminal station circular polarization antenna 28.

  The circuit configuration (electrical connection relationship) of the base station 10 is such that the base station rat race circuit 13 in FIG. 3 is replaced with a first base station 90 ° hybrid coupler 15, and the Wilkinson two synthesis circuit 14 is replaced with the second base station 90. Equivalent to the one replaced by the hybrid coupler 16.

  Specifically, the input of the transmission circuit 1 is coupled to the port 1 of the first base station 90 ° hybrid coupler 15, and the port 2 of the first base station 90 ° hybrid coupler 15 is terminated with a resistor. Port 3 and port 4 of base station 90 ° hybrid coupler 15 are coupled to port 1 of first circulator 5 and second circulator 6, respectively, and port 2 of the first and second circulators is connected to each swivel bias. A first base station circularly polarized antenna 7 and a second base station circularly polarized antenna 8 having different wave directions are combined, and a second base station 90 ° hybrid coupler is connected to port 3 of the first and second circulators. Port 1 and port 2 of 16 respectively, and the port 3 of the second base station 90 ° hybrid coupler 16 is terminated with a resistor, and the second base station 90 ° hybrid coupler Reception circuit 2 to 16 port 4 is coupled.

  The circuit configuration of the terminal station 20 is equivalent to that obtained by replacing the terminal station rat race circuit 33 in FIG. 3 with a terminal station 90 ° hybrid coupler 35.

  Specifically, the terminal station 20 includes a first terminal station circularly polarized antenna 27 and a second terminal station circularly polarized antenna 28 having different directions of swirl polarization, and the first and second terminal stations Port 3 and port 4 of terminal station 90 ° hybrid coupler 35 are coupled to the circularly polarized antenna, port 2 of terminal station 90 ° hybrid coupler 35 is terminated with a resistor, and port 1 of terminal station 90 ° hybrid coupler 35 is terminated. The modulator 21 is coupled to the above.

  An electromagnetic wave (transmission wave) generated from the transmission circuit 1 of the base station 10 is divided into two by the first base station 90 ° hybrid coupler 15, and the first base station via the first circulator 5 and the second circulator 6. The light is radiated from the circularly polarized antenna 7 and the second base station circularly polarized antenna 8 to the external space substantially losslessly.

Here, the transmission wave will be described. When the transmission wave is input from the port 1 in the first base station 90 ° hybrid coupler 15, the transmission wave output from the port 3 is output from the port 4. The transmitted wave is output with a phase delay of π / 4. Therefore, the transmission waves radiated from the first and second base station circular polarization antennas 7 and 8 have a phase difference of π / 4.

  A received wave re-radiated from the terminal station 20 and coming from the outside is input from the first base station circularly polarized antenna 7 and the second base station circularly polarized antenna 8, and the first and second circulators 5 and 6 Via the second base station 90 ° hybrid coupler 16 and is transmitted to the receiving circuit 2 with almost no loss.

  Here, the received wave will be described. The phase of the received wave from the first base station circularly polarized antenna 7 is delayed by π / 4 with respect to the received wave from the second base station circularly polarized antenna 8. (Refer to the description of the terminal station 20 described later). In the second base station 90 ° hybrid coupler 16, the phase of the received wave input from port 2 is delayed by π / 4 with respect to the received wave input from port 1. Therefore, the received wave that passes through the first base station circularly polarized antenna 7 and the first circulator 5 and is input to the port 1 of the second base station 90 ° hybrid coupler 16 and the second base station circularly polarized wave The received wave that has passed through the antenna 8 and the second circulator 6 and is input to the port 2 of the second base station 90 ° hybrid coupler 16 has a phase difference at the port 4 of the second base station 90 ° hybrid coupler 16. In-phase synthesis.

  On the other hand, a part of the output of the transmission circuit 1 that has been divided into two by the first base station 90 ° hybrid coupler 15 leaks in the first and second circulators 5 and 6 (around wave), and the second base Propagates to the station 90 ° hybrid coupler 16. However, these sneak waves are subjected to reverse phase synthesis by the second base station 90 ° hybrid coupler 16, so transmission to the receiving circuit 2 is substantially blocked.

  Here, the reverse phase synthesis will be described. A sneak wave that wraps around at the first circulator 5 and is input to the port 1 of the second base station hybrid coupler 16 wraps around at the second circulator 6 to the second base station. The phase of the sneak wave input to port 2 of the station hybrid coupler 16 is advanced by π / 2. As described above, in the second base station 90 ° hybrid coupler 16, the phase of the received wave input from port 2 is delayed by π / 4 with respect to the received wave input from port 1.

  Accordingly, the first circulator 5 wraps around the received wave input to the port 1 of the second base station 90 ° hybrid coupler 16 and the second circulator 6 wraps around the second base station 90 ° hybrid coupler 16. The received wave input to port 2 is subjected to reverse phase synthesis (cancelled) at port 4 of second base station 90 ° hybrid coupler 16 with a phase difference of π / 2.

  In the terminal station 20, the first terminal station circularly polarized antenna 27 receives the electromagnetic wave radiated from the first base station circularly polarized antenna 7, and the second terminal station circularly polarized antenna 28 receives The electromagnetic wave radiated from the first base station circularly polarized antenna 8 is received.

Therefore, the received wave of the first terminal station circularly polarized antenna 27 is advanced in phase π / 4 with respect to the received wave of the received antenna 28 of the second terminal station polarized antenna 28. These received waves are input to the port 3 and the port 4 of the terminal station 90 ° hybrid coupler 35, respectively, and the phase difference disappears at the port 1 of the terminal station 90 ° hybrid coupler 35, and the signals are combined in phase and output.

Conversely, the electromagnetic wave from the modulator 21, the terminal station 90 ° hybrid coupler 35, the electromagnetic wave output from the port 3, the phase [pi / 4 delayed with respect to the electromagnetic waves output from the port 4. Therefore, the phase of the electromagnetic wave radiated from the first terminal station circularly polarized antenna 27 is delayed by π / 4 with respect to the electromagnetic wave radiated from the second terminal station circularly polarized antenna 28.

  According to the communication system of the present embodiment, as in the communication system of FIG. 1, the disturbance of the power of the carrier wave generated by the transmission circuit 1 to the electromagnetic wave rearriving at the base station can be suppressed. It has the same effect as the communication system.

  Further, compared to the communication system of FIG. 1, the 180 degree phase shifter 4 can be omitted, so that the number of components of the base station 10 and the terminal station 20 can be reduced, and the manufacture of the base station 10 and the terminal station 20 can be reduced. This has the effect of reducing costs.

  An example of the communication system according to this embodiment will be described. FIG. 7 shows the structure of the base station 10 of FIG. 6, and FIG. 8 is a transparent perspective view showing the structure of the terminal station 20 of FIG.

  As shown in FIG. 7, the base station includes a multilayer board having a three-layer structure of a surface layer 101, an intermediate ground layer 105, and a back layer 102. A first dielectric layer 103 is formed between the surface layer 101 and the intermediate ground layer 105, a second dielectric layer 104 is formed between the back layer 102 and the intermediate ground layer 105, and the first dielectric layer 103 is formed on the back layer 102. A base station circularly polarized antenna 47 and a second base station circularly polarized antenna 48 are formed. The surface layer 101 has a transmitter circuit 41, a first base station 90 ° hybrid coupler circuit 55, and a second base station 90 ° hybrid. A coupler circuit 56, a terminating resistor 59, a first circulator 45, a second circulator 46, and a receiving circuit 42 are formed. Transmitter circuit 41, receiver circuit 42, first and second circulators 45 and 46, first and second base station 90 ° hybrid coupler circuits 55 and 56, termination resistor 59, first and second base station circular bias The electrical connection relationship between the wave antennas 47 and 48 is the same as that of the base station 10 of FIG. One end of the terminating resistor 59 is electrically coupled to the intermediate ground layer 105 through the through-hole 114, and the electrical coupling between the first and second circulators and the first and second base station circularly polarized antennas is determined by the intermediate ground layer. The through-hole 115 provided in the layer 105 is contactlessly penetrated and is formed by the second through-hole 116.

  Further, as shown in FIG. 8, the terminal station includes a multilayer substrate having a three-layer structure of a surface layer 101, an intermediate ground layer 105, and a back layer 102. A first dielectric layer 103 is formed between the surface layer 101 and the intermediate ground layer 105, a second dielectric layer 104 is formed between the back layer 102 and the intermediate ground layer 105, and the first dielectric layer 103 is formed on the back layer 102. A terminal base station circular polarization antenna 67 and a second terminal station circular polarization antenna 68 are formed, and a modulation circuit 61, a terminal station 90 ° hybrid coupler circuit 75, and a termination resistor 69 are formed on the surface layer 101. The electrical connection relationship of the modulation circuit 61, the terminal station 90 ° hybrid coupler circuit 75, the termination resistor 69, and the first and second terminal base station circularly polarized antennas 67 and 68 is the same as that of the terminal station 20 in FIG. One end of the terminating resistor 69 is electrically coupled to the intermediate ground layer 105 through the through hole 114, and electrical coupling between the terminal station 90 ° hybrid coupler circuit and the first and second base station circularly polarized antennas The through-hole 115 provided in the layer 105 is contactlessly penetrated and is formed by the second through-hole 116.

  According to the present embodiment, the base station 10 and the terminal station 20 of the embodiment of FIG. 4 can be formed with an integrated thin plate structure using a general-purpose printed multilayer substrate process, and can be realized in a small size and at a low cost.

  Next, a fifth embodiment will be described based on FIG.

  As shown in FIG. 9, the communication system of the present embodiment is different from the communication system of FIG. 3 in that the modulator 21 is replaced with a changeover switch 36 terminated with a load resistor 37.

  By opening and closing the changeover switch 36, the input impedances of the first terminal station circularly polarized antenna 27 and the second terminal station circularly polarized antenna 28 change, so the terminal station 20 of the electromagnetic waves radiated from the base station 10 is changed. The reflection coefficient at can be changed. Therefore, the amplitude of the re-radiated electromagnetic wave to the base station 10 can be modulated. Since the changeover switch 36 and the load resistor 37 can be realized in small size with inexpensive parts, it is effective in reducing the size and cost of the terminal station of the communication system.

  Next, a sixth embodiment will be described based on FIG.

  As shown in FIG. 10, the communication system of the present embodiment uses a carrier wave generation circuit 19 as the transmission circuit 1 in the communication system of FIG. 9.

  In the present embodiment, since the carrier wave generator 19 that can be realized with a simple circuit configuration is used as the transmission circuit 1, it is effective in reducing the size of the base station of the communication system.

  In general, the first and second circulators 5 and 6 and the base station rat race circuit 13 are practically difficult to maintain the same performance in a wide frequency range. In the present embodiment, by using the carrier wave generator 19 that generates a transmission wave having a very narrow frequency band, only the single frequency (there is almost no phase shift) that minimizes the occupied frequency band is used for the circulators 5 and 6. As a result, it is possible to increase the canceling effect by the reverse phase synthesis of the leaking wave.

  Next, a seventh embodiment will be described based on FIG.

  As shown in FIG. 11, the communication system of this embodiment is different from the base station of FIG. 4 that is an example of the embodiment of FIG. The difference is that instead of the local circularly polarized antenna 48, a left-right and right-side polarized wave generating antenna 49 having two feeding points is replaced.

  According to the present embodiment, the maximum size of the left and right polarized antennas can be increased as compared with the base station of the embodiment of FIG. 4, so that the antenna gain of the base station of the PDD communication system can be increased. This is effective in extending the communication distance of the communication system.

  Next, an eighth embodiment will be described with reference to FIG.

  As shown in FIG. 10, the communication system according to the present embodiment includes the terminal station 20 and the base station 10 according to the above-described embodiment as constituent elements.

  For the sake of simplicity of understanding, a pair of base station and terminal station, each representing a circularly polarized antenna with a different direction of polarization, is represented by one symbol, the base station side is represented by antenna 17, and the terminal station side is represented by antenna 18. Yes.

  The terminal station 20 includes a changeover switch 92, a matching circuit 93, a rectifier circuit 94, a smoothing circuit 95, a microprocessor 96, and a memory 97. The changeover switch 92 is connected in parallel to the antenna 18, and the input power of the antenna 18 is equal to the matching circuit. 93 is input to the rectifier circuit 94 through the smoothing circuit 95 and becomes the power source of the microprocessor 96. The microprocessor 96 refers to the information stored in the memory 97 in advance and changes the input impedance of the antenna 18 by opening and closing the switch 92 to change the single frequency electromagnetic wave 81 radiated from the base station antenna 17. Is subjected to amplitude modulation.

  According to the present embodiment, since the electromagnetic wave received by the antenna 18 is used as the power of the terminal station 11, remote communication can be realized without using an internal power source such as a battery. As a result, it is possible to realize wireless information transmission in an environment where it is difficult to use a battery in a terminal station due to environment, maintenance, lifespan, and the like.

  Next, a ninth embodiment will be described based on FIG.

  As shown in FIG. 13, the communication system of this embodiment has a plurality of terminal stations in the communication system of the previous embodiment. In the drawing, as in the previous embodiment, each set of circularly polarized antennas having different turning directions in a set of base stations and terminal stations is represented by one symbol.

  In the present embodiment, there are three terminal stations 200, 201, and 202, and the base station 10 needs to identify and recognize each of the terminal stations 200, 201, and 202. The terminal stations 200, 201, and 202 are provided with antennas 180, 181, and 182 respectively, and the on / off pattern of the changeover switch is different in time series according to the contents of the internal memory.

  According to this configuration, it is possible to shift the transmission timing of scattered electromagnetic waves from the antennas 180, 181, and 182 in a certain period, and the base station 10 detects these timings, whereby these three terminal stations 200 and 201 are detected. , 202 can be identified.

  According to the communication system of the present embodiment, since the base station can identify a plurality of terminal stations, there is an effect of increasing the communication capacity of the entire communication system.

It is a circuit diagram which shows the structure of the communication system of suitable 1st embodiment which concerns on this invention. It is a circuit diagram which shows the structure of the communication system of suitable 2nd embodiment which concerns on this invention. It is a circuit diagram which shows the structure of the communication system of suitable 3rd embodiment which concerns on this invention. It is a transparent perspective view which shows the detailed structure of the base station of the communication system of FIG. It is a transparent perspective view which shows the detailed structure of the base terminal of the communication system of FIG. It is a circuit diagram which shows the structure of the communication system of suitable 4th embodiment which concerns on this invention. It is a transparent perspective view which shows the detailed structure of the base station of the communication system of FIG. It is a transparent perspective view which shows the detailed structure of the base terminal of the communication system of FIG. It is a circuit diagram which shows the structure of the communication system of suitable 5th embodiment which concerns on this invention. It is a circuit diagram which shows the structure of the communication system of suitable 6th Embodiment which concerns on this invention. It is a transparent perspective view which shows the structure of the communication system of suitable 7th embodiment which concerns on this invention. It is a circuit diagram which shows the structure of the communication system of suitable 8th embodiment which concerns on this invention. It is a circuit diagram which shows the structure of the communication system of suitable 9th embodiment which concerns on this invention. It is a block diagram which shows the conventional communication system.

DESCRIPTION OF SYMBOLS 1 Transmission circuit 2 Reception circuit 3 In-phase two divider | distributor 4 180 degree | times phase shifter 5 1st circulator 6 2nd circulator 7 1st base station circularly polarized antenna 8 2nd base station circularly polarized antenna 9 In-phase 2 Synthesizer 10 Base station 13 Rat race circuit 14 Wilkinson two synthesis circuit 15 First base station 90 ° hybrid coupler 16 Second base station 90 ° hybrid coupler 17 Base station antenna 18 Terminal station antenna 19 Carrier generation circuit 20 Terminal station 21 Modulator 23 In-phase two-combiner 24 180-degree phase shifter 27 First terminal station circularly polarized antenna 28 Second terminal station circularly polarized antenna

Claims (9)

A communication system comprising a base station and a terminal station,
The base station comprises a transmit and receive circuits,
Coupling the transmitter circuit to port 1 of the first base station 90 ° hybrid coupler;
Port 2 of the first base station 90 ° hybrid coupler is terminated with a resistor,
It said port 1 of the respective first and second circulator is coupled to the ports 3 and 4 of the first base station 90 ° hybrid coupler,
First and second base station circularly polarized antennas having different swirl polarization directions are coupled to port 2 of the first and second circulators,
Port 1 and port 2 of the second base station 90 ° hybrid coupler are coupled to port 3 of the first and second circulators, respectively.
Port 3 of the second base station 90 ° hybrid coupler is terminated with a resistor,
The receiving circuit is coupled to port 4 of the second base station 90 ° hybrid coupler,
The terminal station comprises first and second terminal station circularly polarized antennas each having different swirl polarization directions,
Ports 3 and 4 of the terminal station 90 ° hybrid coupler are coupled to the first and second terminal station circularly polarized antennas, and port 2 of the terminal station 90 ° hybrid coupler is terminated with a resistor.
A communication system, wherein a modulator is coupled to port 1 of the terminal station 90 ° hybrid coupler. The communication system according to claim 1 , wherein the modulator switches an input impedance of an antenna. The communication system according to claim 1 or 2, wherein the transmission circuit is a carrier wave generation circuit. The base station is formed using a single multilayer board, components other than the base station circular polarization antenna is mounted on the surface of the multilayer substrate, two base stations circular polarization turning the polarization direction are different antenna communication system according to any one of claims 1 to 3 which is mounted on the rear surface of the multilayer substrate. The communication system according to claim 4, wherein the two base station circularly polarized antennas are realized by a series of plane structures including two feeding points. The terminal station is formed using a single multilayer board, components other than the terminal station circular polarization antenna is mounted on the surface of the multilayer substrate, two terminal stations circular polarization turning the polarization direction are different antenna communication system according to any one of claims 1 to 5 is mounted on the rear surface of the multilayer substrate. The communication system according to claim 6 , wherein the two terminal-station circularly polarized antennas are realized by a series of plane structures including two feeding points. The terminal station comprises a rectifier circuit and a microprocessor with memory circuits and the changeover switch, the rectifier circuit energy of the input electromagnetic wave from the two terminal station circular polarization antenna is supplied to the microprocessor, the microsensor the processor according to any one of claims 1 to 7 to switch the input impedance of the two terminal stations circularly polarized antenna by turning on and off the changeover switch based on the information stored in the storage circuit at a constant rule Communication system. The terminal station there are a plurality of communication system according to the transmission timing is different from each other claims 1-8 or of the modulation signal to be transmitted of each terminal station.

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