JP2007166255A - High frequency transmitter-receiver and base station transmitter-receiver communicating with the high frequency transmitter-receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency transmitter-receiver capable of attaining a compact transceiver and a base station transmitter-receiver for communicating with the high frequency transmitter-receiver. <P>SOLUTION: In the high frequency transmitter-receiver in which a voltage controlled oscillator 21 modulates a signal input to a transmission data input terminal 28 and transmits the signal from an oscillating coil 22, a lowpass filter 46 for receiving an output of a loop filter 27 of a PLL loop and a reception data output terminal 47 with an output of the lowpass filter 46 connected thereto are provided, and a changeover switch 41 for selectively switching a signal received by a receiving antenna 42 and a signal from a crystal oscillator 25 and outputting the switched signal to a frequency divider 26 is inserted between the crystal oscillator 25 and the frequency divider 26. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high frequency transmission / reception apparatus and a base station transmission / reception apparatus communicating with the high frequency transmission / reception apparatus.

  An endoscope is a useful examination device for the early detection of visceral diseases in the digestive system. However, with a fiber-type endoscope, the fiber is inserted during the examination, which causes pain to the subject. In addition, the fiber type endoscope has a problem that the small intestine cannot be examined.

  FIG. 6 is a cross-sectional view of a capsule endoscope 1 recently proposed in order to alleviate this pain and to enable examination of the small intestine. As shown in FIG. 6, in the capsule 2 made of resin of the capsule endoscope 1, in addition to the light emitting means 3 and the imaging means 4, a transmitter 5 and a control circuit 6 for controlling these circuits, and each of these A battery 7 for operating the circuit is accommodated. The capsule 2 has a diameter of about 11 mm and a length of about 25 mm.

  FIG. 7 is an explanatory diagram of an inspection method in the capsule endoscope 1. In FIG. 7, the capsule endoscope 1 takes a photograph of the stomach or intestine when the subject 11 drinks, and transmits the digital photograph data (used as an example of a transmission signal) from the transmitter 5 to the outside of the body wirelessly. To do. Photo data sent from the transmitter 5 is received by the external antenna 12 attached to the body. A signal received by the extracorporeal antenna 12 is input to the extracorporeal unit 13. The extracorporeal unit 13 demodulates the signal received by the antenna into the original digital photo data and stores it in a memory or the like.

  Next, FIG. 8 is a circuit block diagram of a conventional transmitter 5 used in the conventional capsule endoscope 1. In FIG. 8, the voltage-controlled oscillator 21 changes its oscillation frequency according to the voltage supplied to the oscillation frequency control terminal 21a. The output of the voltage controlled oscillator 21 is input to the frequency divider 23, divided by a predetermined frequency dividing ratio, and supplied to one input 24a of the phase comparator 24. On the other hand, the other input 24 b of the phase comparator 24 is supplied with a signal from a crystal oscillator 25 (used as an example of a reference frequency oscillator) via a frequency divider 26. The phase comparator 24 outputs a pulse signal having a voltage corresponding to the phase difference between the signals input to the inputs 24a and 24b.

  A loop filter 27 is inserted between the output of the phase comparator 24 and the oscillation frequency control terminal 21a. The oscillation frequency of the voltage controlled oscillator 21 changes in accordance with the signal output from the loop filter 27. That is, this is a so-called PLL circuit.

  Here, the transmission data input terminal 28 is connected to the oscillation frequency control terminal 21a. When the photographed digital photograph data is input to the transmission data input terminal 28, the oscillation frequency of the voltage controlled oscillator 21 is changed by the digital photograph data. Here, the oscillation coil 22 also operates as a transmission antenna, and digital photographic data is transmitted from the oscillation coil 22.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2001-104241 A

  However, in the capsule endoscope 1 using such a conventional transmitter 5, the posture of the capsule endoscope 1 cannot be controlled in the body, and the imaging region cannot be indicated. Therefore, in order to perform posture control of the capsule endoscope 1 in the body, a configuration for transmitting a signal for controlling the posture from the external antenna 12 to the capsule endoscope 1 is necessary. That is, it is necessary to separately provide a transmitter (not shown) on the external unit 13 side and a receiver (not shown) on the capsule endoscope 1 side. However, in particular, providing a separate receiver in the capsule endoscope 1 has a problem that the capsule 2 becomes large and the pain when the subject swallows becomes large.

  Accordingly, the present invention has been made to solve this problem, and an object of the present invention is to provide a small high-frequency transceiver.

  In order to achieve this object, a high-frequency transceiver according to the present invention includes a low-pass filter to which an output of a loop filter is supplied and a reception data output terminal to which the output of the low-pass filter is connected. The first switching means for selectively switching the signal received by the receiving antenna and the signal from the reference frequency oscillator and outputting to the second frequency divider is inserted between the frequency divider and the frequency divider. It is a thing. Thereby, the intended purpose can be achieved.

  As described above, according to the present invention, the voltage controlled oscillator whose oscillation frequency changes according to the voltage supplied to the oscillation frequency control terminal, the first frequency divider to which the output of the voltage controlled oscillator is connected, A phase comparator in which an output of the first frequency divider is connected to one input and a signal output from a reference frequency oscillator is connected to the other input via a second frequency divider; A loop filter inserted between the output of the phase comparator and the oscillation frequency control terminal, a transmission data input terminal connected to the oscillation frequency control terminal, and a first transmission connected to the voltage controlled oscillator. A low-pass filter having a credit antenna, to which the output of the loop filter is supplied, and a reception data output terminal to which the output of the low-pass filter is connected, between the reference frequency oscillator and the second frequency divider Is selectively switch between the signals from the received signal and the reference frequency oscillator in the receiving antenna, an RF transceiver device first switching means for outputting to the second frequency divider is inserted.

  As a result, the phase comparator, the voltage controlled oscillator, the first frequency divider, and the like can be shared and used during reception. That is, there is no need to provide a separate receiver, and the high-frequency transmitter / receiver can be reduced in size.

(Embodiment 1)
Hereinafter, the present embodiment will be described with reference to the drawings. FIG. 2 is an explanatory diagram of an inspection method using the capsule endoscope 32 using the transceiver 31 according to the present embodiment. In FIG. 2, the same components as those in FIG. In the capsule endoscope 32 in the present embodiment, the transmitter 5 in the conventional capsule endoscope 1 shown in FIG. 6 is replaced with a transmitter / receiver 31, and the control circuit 6 also performs control during reception.

  First, an inspection method using the capsule endoscope 32 in the present embodiment will be described with reference to FIG. When the subject 11 drinks the capsule endoscope 32, the imaging means 4 of the capsule endoscope 32 takes pictures of the stomach and intestines at intervals of two per second, and the digital photograph data (as an example of a transmission signal) Used) is transmitted from the transceiver 31 to the outside of the body by radio. Photo data sent from the transceiver 31 is received by an extracorporeal antenna 33 (used as an example of a base station receiving antenna and a base station transmitting antenna) attached to the body. A signal received by the extracorporeal antenna 33 is input to the extracorporeal unit 34. This extracorporeal unit 34 is also the same as the conventional capsule endoscope 1 in that the signal received by the antenna is demodulated into the original digital photographic data and stored in a memory or the like.

  In general, photographing inside the body is performed in this state. Therefore, the test subject 11 can acquire the test data while living normally. However, when the doctor 35 inspects in a hospital or the like, the doctor 35 inspects the state of the affected part on the display 36a of the inspection device 36 while controlling the posture of the capsule endoscope 32 in order to confirm the state of the affected part in detail. To do. For this purpose, the extracorporeal device 34 and the inspection device 36 are connected, and a posture control command for controlling the posture of the capsule endoscope 32 is input from the input means 36b (keyboard, mouse, operation switch, etc.) of the inspection device 36. . The command input in this way is sent to the capsule endoscope 32 through the extracorporeal antenna 33 as a posture control signal. Then, the vibration element 50 (shown in FIG. 1) housed in the capsule endoscope 32 is vibrated to change to an arbitrary posture. Thereby, since the doctor 35 can inspect the affected part which he wants to see firmly, it becomes difficult to miss a fine affected part.

  Next, the capsule endoscope 32 in the present embodiment will be described below with reference to the drawings. FIG. 1 is a circuit block diagram of a capsule endoscope 32 using a transceiver 31 in the present embodiment. 1, the same components as those in FIG. 8 are denoted by the same reference numerals, and the description thereof is simplified.

  First, the transceiver 31 will be described with reference to FIG. The oscillation frequency of the voltage controlled oscillator 21 changes according to the voltage supplied to the oscillation frequency control terminal 21a. This is achieved by connecting the oscillation coil 22 to the voltage controlled oscillator 21 and a capacitance diode (not shown) connected in parallel to the oscillation coil 22 and changing the voltage applied to the oscillation frequency control terminal 21a. The oscillation frequency is changed by changing the capacitance of the variable capacitance diode.

  The output of the voltage controlled oscillator 21 is input to the frequency divider 23, divided by a predetermined frequency dividing ratio, and supplied to one input 24a of the phase comparator 24. On the other hand, the other input 24 b of the phase comparator 24 is supplied with a signal from a crystal oscillator 25 (used as an example of a reference frequency oscillator) via a frequency divider 26. The phase comparator 24 outputs a pulse signal having a voltage corresponding to the phase difference between the signals input to the inputs 24a and 24b. While the oscillation frequency of the voltage controlled oscillator 21 is 315 MHz and the oscillation frequency of the crystal oscillator 25 is 26 MHz, the frequencies after frequency division by the frequency dividers 23 and 26 are substantially the same. In this manner, the frequency division ratio between the frequency divider 23 and the frequency divider 26 is set.

  A loop filter 27 is inserted between the output of the phase comparator 24 and the oscillation frequency control terminal 21a. The pulse signal output from the phase comparator 24 passes through the loop filter 27 and becomes a substantially DC signal. The oscillation frequency of the voltage controlled oscillator 21 changes according to the voltage value of the DC signal output from the loop filter 27. That is, this is a so-called PLL circuit, and the voltage controlled oscillator 21 is locked to a frequency of about 315 MHz.

  A transmission data input terminal 28 is connected to the oscillation frequency control terminal 21a, and digital photo data input from the transmission data input terminal 28 is supplied. The oscillation frequency of the voltage controlled oscillator 21 changes according to the voltage output from the loop filter 27 and the voltage of the digital photo data. That is, the digital photo data is directly FSK modulated by the voltage controlled oscillator 21. In the present embodiment, the oscillation coil 22 also operates as a transmission antenna, and modulated digital photo data is transmitted from the oscillation coil 22. Therefore, there is no need to provide a separate transmission antenna, and the transceiver 31 can be downsized.

  Here, a changeover switch 41 is inserted between the crystal oscillator 25 and the frequency divider 26. Specifically, the crystal oscillator 25 is connected to one terminal of the changeover switch 41, and the attitude control signal received by the receiving antenna 42 is supplied to the other terminal via the amplifier 43. The common terminal of the changeover switch 41 is connected to the input of the frequency divider 26. Here, the carrier frequency of the attitude control signal input to the receiving antenna 42 is set to be the same as the oscillation frequency of the crystal oscillator 25. By doing so, it is not necessary to change the frequency dividing ratio in the frequency divider 26, so that the circuit configuration is facilitated.

  What is important here is that the carrier frequency of the attitude control signal is lower than the oscillation frequency of the voltage controlled oscillator 21. As the high frequency signal passing through the human body has a lower frequency, loss due to passage through the human body becomes smaller. Here, the level of the signal transmitted from the extracorporeal device 34 and the level of the signal transmitted from the capsule endoscope 32 and released to the outside through the human body are strictly determined by laws and regulations. However, since the signal transmitted from the capsule endoscope 32 side is lost by the human body, it can be transmitted at a large level corresponding to the loss. On the other hand, since the signal transmitted from the extracorporeal device 34 is directly released into the air, it must be transmitted at a level smaller than the level of the signal transmitted from the capsule endoscope 32 side. Therefore, by setting the frequency of the signal transmitted from the external unit 34 to a low frequency, the loss of the signal due to the passage of the human body is reduced, and the posture control signal transmitted from the external unit 34 by the transceiver 31 of the capsule endoscope 32. Can be received reliably.

  Further, in the present embodiment, a changeover switch 44 is inserted between the loop filter 27 and the oscillation frequency control terminal 21a. A signal input to the loop filter 27 and the transmission data input terminal 28 is supplied to one terminal of the changeover switch 44. The other terminal of the changeover switch 44 is connected to a power supply circuit 45 that generates a specified voltage. In the present embodiment, when the changeover switch 44 is connected to the power supply circuit 45 side, the voltage controlled oscillator 21 is set to a frequency different from the frequency of the carrier wave at the time of transmission (315 MHz). This is to prevent the external unit 34 from mistaking this signal for photographic data when the voltage-controlled oscillator 21 oscillates at the same frequency as at the time of transmission.

  The output of the phase comparator 24 is connected to the reception data output terminal 47 through the low pass filter 46. As a result, the pulse signal having a narrow pulse width output from the phase comparator 24 is shaped so that the level can be determined by the comparator 48 described later.

  The control circuit 6 is connected to the transmission data input terminal 28 and the reception data output terminal 47 of the transceiver 31 configured as described above. As a result, the digital photo data input from the imaging unit 4 is supplied to the transmission data input terminal 28. On the other hand, the output of the reception data output terminal 47 is supplied via a comparator 48 inserted between the reception data output terminal 47 and the control circuit 6. The comparator 48 uses the voltage of the reference voltage 49 as a threshold value, and compares the threshold value with the signal level output from the low-pass filter 46 to reproduce the attitude control signal. The control circuit 6 to which this posture control signal is input vibrates the vibration element 50 and changes the posture of the capsule endoscope 32. The output of the control circuit 6 is also connected to both the changeover switch 41 and the changeover switch 44, and the control circuit 6 also controls switching between transmission and reception.

  In the present embodiment, the changeover switch 44 is inserted between the loop filter 27 and the oscillation frequency control terminal 21a, but this may be after the branch point of the reception data output terminal 47.

  Next, operations of transmission and reception of the transceiver 31 in the present embodiment will be described with reference to the drawings. FIG. 3 is a time chart of the transceiver 31 in the present embodiment. The imaging means 4 periodically takes two photos per second. That is, the digital photo data 61 is sent at a constant cycle 62 of about every 0.5 seconds. The digital photo data 61 in the present embodiment has a transmission rate of about 4.5 Mbit / sec. On the other hand, the attitude control signal 63 is switched so as to be received after the maximum data transmission time 64 in the digital photo data 61 has elapsed.

  The control circuit 6 reproduces the synchronous clock 65 by detecting the first rising edge of the digital photo data 61 sent periodically. The control circuit 6 detects the rising edge of the synchronous clock 65 and operates the transmitter / receiver 31 as a transmitter. That is, at the rise of the synchronous clock 65, the changeover switch 41 is connected to the crystal oscillator 25 side, and the changeover switch 44 is switched to the loop filter 27 side. As a result, the circuit operates as a PLL circuit, and the phase comparator 24 compares the phase of the signal output from the voltage controlled oscillator 21 with the phase of the signal output from the crystal oscillator 25, and a voltage corresponding to the phase shift oscillates. It is supplied to the frequency control terminal 21a. At this time, the voltage controlled oscillator 21 is locked to a frequency of 315 MHz. In this state, when digital photograph data is input, the voltage of the oscillation frequency control terminal 21a is increased by the data voltage during the high period, so that the frequency of the voltage controlled oscillator 21 is shifted and FSK modulation is performed. The data modulated in this way is transmitted from the oscillation coil 22. Here, it is important that the high time 66 in the synchronous clock 65 is longer than the maximum data transmission time 64. By doing so, it is possible to reliably switch between transmission and reception.

  Next, the control circuit 6 switches the transceiver 31 to the reception operation at the falling edge of the synchronous clock 65. That is, the control circuit 6 switches the changeover switch 41 to the receiving antenna 42 side and switches the changeover switch 44 to the reference voltage 49 side. Thus, the phase comparator 24 compares the phase of the signal input from the receiving antenna 42 with the phase of the output signal from the voltage controlled oscillator 21 and outputs a pulse signal corresponding to the phase difference. Here, since the pulse signal output from the phase comparator 24 is a spike-like pulse signal with a very short ON time, passing the low-pass filter 46 allows the comparator 48 to detect the high time. Shape into a waveform like this.

  The comparator 48 compares the threshold value (voltage value of the reference voltage 49) with the output level from the low-pass filter 46 to detect high / low, and the attitude control signal is reproduced. When this attitude control signal is input, the control circuit 6 vibrates the vibration element 50. The transmission speed of the attitude control signal is as slow as about 10 Kbit / sec. However, since it is a command of several bits, the reception time 67 is completed in a very short time. Therefore, the attitude control signal can be sufficiently received even during the short non-transmission time 68 of the transmission data.

  With the configuration as described above, the transmitter / receiver 31 in the present embodiment is configured to switch between transmission and reception by switching the changeover switch at predetermined time intervals, so that transmission and reception are performed. There is no need to construct a circuit for each. Specifically, the voltage-controlled oscillator 21, the oscillation coil 22, the frequency divider 23, the frequency divider 26, the phase comparator 24, the loop filter 27, and the like can be shared for transmission and reception. 31 can be realized.

  In this embodiment, the changeover switch 44 changes the oscillation frequency of the voltage-controlled oscillator 21 for transmission and reception. However, the same frequency may be used. In this case, since the changeover switch 44 is not necessary, there is no loss in the changeover switch 44 of the oscillation frequency signal, so that C / N is good. However, in such a case, when the transmitter / receiver 31 receives the attitude control signal, a transmission signal of 315 MHz is transmitted from the oscillation coil 22. Therefore, in such a case, erroneous data is transferred from the output terminal 72 to the inspection device 36 by turning off the operation of the base station receiver 71 housed in the extracorporeal unit 34 (used as an example of the base station transceiver). It is only necessary to prevent it from being sent out.

  In this case, for example, as shown in FIG. 4, the extracorporeal antenna 33 is used as an extracorporeal antenna 33a for reception (used as an example of a reception antenna for a base station) and an extracorporeal antenna 33b for transmission (used as an example of a transmission antenna for a base station). For example). Furthermore, the extracorporeal unit 34 is provided with a base station receiver 71 and a base station transmitter 73 connected to the extracorporeal antennas 33a and 33b, and outputs from the base station receiver 71 and the base station transmitter 73 are transmitted to the base station. Input to the station control circuit 74. Further, by connecting the output of the base station control circuit 74 to the drive circuit 75, the base station control circuit 74 outputs a command to turn on and off the base station receiver 71 and the base station transmitter 73 to the drive circuit 75. .

  Specifically, the base station receiver 71 is turned on and the base station transmitter 73 is turned off at the rising edge of the digital photo data 61 in the same manner as the timing of FIG. Then, the synchronous clock 65 is reproduced, and the base station transmitter 73 is turned on and the base station receiver 71 is turned off by the fall of the synchronous clock 65. By doing so, the extracorporeal unit 34 can be reliably switched between transmission and reception.

  In both the transmitter / receiver 31 and the external unit 34, the synchronous clock 65 is reproduced based on the signal of the digital photo data 61, and transmission / reception is switched based on the synchronous clock 65. Synchronization can be ensured. Therefore, it is not necessary to provide a large margin for the time for operating the transceiver 31 as reception with respect to the time of the attitude control signal. Accordingly, since the time during which the transceiver 31 operates as reception can be shortened, there is less possibility of noise and the like, and reliable attitude control can be performed.

  Here, in the base station control circuit 74, when the inspection device 36 is connected, the reproduced digital photograph data is output from the output terminal 72 to the inspection device 36. On the other hand, when the inspection device 36 is not connected, the reproduced digital photo data is stored in a memory (not shown).

  In such a case, the oscillation frequency of the voltage controlled oscillator 21 at the time of transmission and reception at the transceiver 31 is the same. Further, if the frequency of the attitude control signal input to the receiving antenna 42 is the same as the frequency of the crystal oscillator 25, it is not necessary to change the frequency dividing ratio of the frequency divider 23 or frequency divider 26. The configuration can be simplified. Therefore, the transceiver 31 can be reduced in size.

  Furthermore, in the present embodiment, the extracorporeal unit 34 is connected to the inspection device 36, but this may connect the extracorporeal antenna 33 directly to the inspection device 36. However, in this case, it is necessary to provide the inspection device 36 with a base station receiver 71, a base station transmitter 73, a base station control circuit 74, and the like.

(Embodiment 2)
The present embodiment will be described below with reference to the drawings. FIG. 5 is a circuit block diagram of the transceiver 81 in the present embodiment. 5, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is simplified.

  In FIG. 5, the difference from the first embodiment is that the changeover switch 44 and the power supply circuit 45 are not provided, and the output of the loop filter 27 is directly connected to the oscillation frequency control terminal 21a. This is a point constituted by two frequency dividers 23a and 23b, and a point where a changeover switch 82 is inserted between the receiving antenna 42 and the frequency divider 23b. Here, the output of the frequency divider 23a is connected to one input of the changeover switch 82, and the output of the amplifier 43 is supplied to the other input. The common terminal of the changeover switch 82 is connected to the input of the frequency divider 23b. Here, the frequency division ratio of the frequency divider 23 b is the same as the frequency division ratio of the frequency divider 26.

  An amplifier 83 is inserted between the amplifier 43 and the changeover switch 82. This is because the signal level output from the voltage controlled oscillator 21 is about 0 dBm, while the level of the signal received by the receiving antenna 42 is −40 dBm. Since the frequency divider 23b operates normally at the level of the voltage controlled oscillator 21, the frequency divider 23b may not operate normally with a signal of a level input from the receiving antenna 42. Therefore, in this embodiment, by inserting the amplifier 83, even if the changeover switch 82 is switched, the fluctuation in the level of the signal input to the frequency divider 23b can be reduced.

  With this configuration, when the receiving operation is performed by the transmitter / receiver 81, the phase comparator 24 can be configured by setting the changeover switch 41 to the crystal oscillator 25 side and the changeover switch 82 to the reception antenna 42 side. The phases of these signals are compared, and a voltage corresponding to the phase difference is output. In this case, since the phase comparator 24 performs phase comparison based on the frequency of the crystal oscillator 25, an accurate phase difference can be detected. In this case, the power supply of the voltage controlled oscillator 21 can be turned off. In particular, in the case of such a configuration, a crystal oscillator 25 in which frequency fluctuations hardly occur with respect to temperature or the like is used as a reference signal for phase comparison. Thereby, since the reference frequency due to fluctuations in body temperature or the like is not easily changed, stable accuracy can be obtained. Therefore, for example, the transmitter / receiver 81 with good signal determination accuracy can be realized even in the case where an examination has to be performed on a patient with high heat.

  The high-frequency transmitter / receiver according to the present invention has an effect that a small transmitter / receiver can be obtained, and is useful as a transmitter / receiver that is desired to be downsized, such as a capsule endoscope.

1 is a circuit block diagram of a capsule endoscope according to a first embodiment of the present invention. Explanatory drawing of inspection method with capsule endoscope Same as above, time chart in base station transceiver Circuit block diagram of base station transceiver Block diagram of a transceiver according to Embodiment 2 of the present invention Cross section of capsule endoscope Explanatory drawing of the inspection method with the conventional capsule endoscope Same as above, high-frequency transceiver circuit block diagram

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Voltage control oscillator 22 Oscillation coil 23 Frequency divider 24 Phase comparator 25 Crystal oscillator 26 Frequency divider 27 Loop filter 28 Transmission data input terminal 41 Changeover switch 42 Reception antenna 46 Low pass filter 47 Reception data output terminal

Claims (9)

A voltage controlled oscillator whose oscillation frequency changes according to a voltage supplied to the oscillation frequency control terminal, a first frequency divider to which an output of the voltage controlled oscillator is connected, and an output of the first frequency divider are A phase comparator connected to one input and a signal output from a reference frequency oscillator connected to the other input via a second frequency divider, an output of the phase comparator and the oscillation frequency A loop filter inserted between the control terminal, a transmission data input terminal connected to the oscillation frequency control terminal, a first transmission antenna connected to the voltage controlled oscillator, and an output of the loop filter And a reception data output terminal to which the output of the low-pass filter is connected, and a reception antenna receives between the reference frequency oscillator and the second frequency divider. By switching the signals from the signal and the reference frequency oscillator selectively, high-frequency transceiver device first switching means for outputting to the second frequency divider is inserted. The high-frequency transmitting / receiving apparatus according to claim 1, further comprising an oscillation coil connected to a voltage controlled oscillator, wherein the oscillation coil is used as a transmission antenna. The high frequency transmission / reception apparatus according to claim 1, wherein the frequency of the reception signal received by the reception antenna is the same as the frequency of the signal generated by the reference frequency oscillator. The high-frequency transmission / reception apparatus according to claim 1, wherein a frequency of a reception signal received by the first reception antenna is lower than a frequency of a transmission signal transmitted from the transmission antenna. Between the voltage controlled oscillator and the first frequency divider, a second switch is provided in which the output of the voltage controlled oscillator is supplied to one input and the signal received by the receiving antenna is supplied to the other input. The high frequency transmission / reception apparatus according to claim 1, comprising means. 6. The third frequency divider is provided between one input of the second switching means and the voltage controlled oscillator, and the frequency division ratio of the first frequency divider and the second frequency divider is the same. High frequency transmitter / receiver. 2. The high frequency device according to claim 1, further comprising a third switching unit that is connected to the loop filter and selectively supplies one of the signal output from the phase comparator and the DC power source to the oscillation frequency control terminal. Transmitter / receiver. A base station receiving antenna for receiving a transmission signal transmitted by the high frequency transmitting / receiving apparatus according to claim 1, a base station receiver to which a signal received by the base station receiving antenna is supplied, and a base station receiver A base station control circuit to which an output signal is supplied, a base station transmitter to which a signal output from the base station control circuit is supplied, and a base station transmission antenna to which the output of the base station transmitter is connected And the base station control circuit has a nullifying means for invalidating data input from the receiving antenna for the base station after a predetermined time has elapsed since the signal was sent to the transmitter. apparatus. 8. The base station transmission / reception apparatus according to claim 7, wherein the invalidating means is a power supply circuit that controls at least on / off of the base station receiver in accordance with a control signal output from the base station control circuit.

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