JP2001086666A - Microwave supply circuit and its manufacture and mover identifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of the rectification efficiency caused by the property dispersion of a rectifying element, in a responder for a mover identification system. SOLUTION: A capacitor 105 for adjustment is connected between the anode end and the cathode end of a diode 104, and the slippage of the matching condition to the dispersion of the capacity between terminals is corrected by changing the capacity. That is, this is one which prevents the deterioration of the rectification efficiency, by constituting a matching circuit 103, using the standardized value of the capacity between terminals or the average value, and adjusting only the value of the capacitor 105 for adjustment, according to the degree of change, in the case that the capacity between terminals has changed from this value. The capacity of the capacitor 105 for adjustment is, for example, 0 pF-0.5 pF. As a result, an advantageous effect can be obtained such that it can materialize a microwave supply circuit which can easily adjust and improve the deterioration of the rectification efficiency accompanying the property dispersion of the diode 104, by adjusting only the capacity value of the capacitor 105 for adjustment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for receiving a weak microwave radiated and supplying power by a rectified DC voltage, and more particularly to a microwave power supply circuit of a transponder for a moving object identification device and the circuit. The present invention relates to a transponder for a mobile object identification device using a configuration.

[0002]

2. Description of the Related Art Conventionally, a transponder is carried by a person or attached to a mobile body, and information is previously stored in the transponder. The interrogator that has transmitted and received and demodulated the interrogation signal returns an appropriate response signal to the interrogator by radio waves, and the interrogator demodulates the received response signal by appropriate demodulation means, so that the interrogator is stored in the transponder. Devices and systems have been proposed and realized, such as obtaining information on a person and identifying a person or a moving object.

When an electronic circuit in a transponder is operated by a commercial AC power supply or a built-in battery, complicated signal processing and sufficient transmission power can be obtained. Sufficient satisfaction cannot be obtained in terms of life.
For this reason, Japanese Patent Application Laid-Open No. 63-54023 discloses a technique in which electric power of radio waves radiated from an external interrogator toward a transponder is used as driving power.

The outline of the transponder shown here is as shown in FIG. 9 in which a microstrip line 902 and a radiating element 903 selected as a half length of an interrogation signal wavelength are metallized on a substrate 901. An antenna is formed, and the microwave charged wave received by the antenna is converted into a diode 904a.
Then, the response signal is added to the diode 904b and the response signal is transmitted.

[0005]

However, in the above-mentioned conventional configuration, since the connection conditions with the antenna, including the characteristics of the matching circuit, are determined based on the standard characteristics of the diode, the diode characteristics vary. As a result, there is a problem that the energy wave of the microwave charged wave cannot be efficiently converted into DC power.

An object of the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a microwave power supply circuit capable of efficiently obtaining DC power by configuring a diode circuit as described above.

[0007]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention comprises an adjusting element in parallel with a rectifying diode, and is configured to be adjustable according to a variation in diode characteristics.

Thus, a small and inexpensive microwave power supply circuit capable of efficiently obtaining DC power can be constructed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to an antenna for receiving a microwave, a rectifying element for rectifying the received microwave, and an impedance connected in parallel with the rectifying element. An adjusting element, a matching circuit for matching the rectifying element and the antenna, and a low-pass filter for smoothing an output rectified by the rectifying element, wherein the matching circuit is connected to a feeding end of the antenna And
One end of the rectifying element is connected to the matching circuit, and the other end is connected to the low-pass filter, so that the impedance value of the impedance adjusting element is changed according to the variation of the rectifying element to keep the rectification efficiency constant. This is a microwave power supply circuit characterized in that it is maintained, and has a function of adjusting and improving the deterioration of the rectification efficiency of the microwave power supply circuit due to the characteristic variation of the rectifier diode with a simple circuit configuration.

According to a second aspect of the present invention, there is provided an antenna for receiving a microwave, a rectifier for rectifying the received microwave, and an impedance adjusting element connected in parallel with the rectifier. A matching circuit for matching the rectifying element and the antenna, and a low-pass filter for smoothing an output rectified by the rectifying element, connecting the matching circuit to a feeding end of the antenna, One end of the element is connected to the matching circuit and the low-pass filter, and the other end is grounded, so that the impedance value of the impedance adjusting element is changed according to the variation of the rectifying element and the mounting variation, thereby improving the rectification efficiency. It is a microwave power supply circuit characterized by keeping it constant, and with a simple circuit configuration, variations in the characteristics and mounting of rectifier diodes Adjust the deterioration of rectification efficiency of the microwave feed circuit by, it has the effect of brought improved.

According to a third aspect of the present invention, there is provided a substrate on which an antenna for receiving at least a microwave is formed, a rectifying element mounted on the substrate by flip-chip to rectify the received microwave, and the antenna And an IC having a matching circuit for matching the rectifying element, and an impedance adjusting element whose impedance value changes depending on the distance between the IC and the substrate, changing an impedance value of the impedance adjusting element, It is a microwave power supply circuit characterized by adjusting the rectification efficiency, and by adjusting the impedance of the impedance adjustment element according to the variation of the rectifier diode, the microwave power supply circuit due to the characteristic variation of the rectifier diode It has the effect of improving the rectification efficiency.

According to a fourth aspect of the present invention, there is provided a substrate on which at least an antenna for receiving a microwave is formed, a rectifying element mounted on the substrate by flip-chip to rectify the received microwave, and the antenna. An IC having a matching circuit for matching the rectifier element, and an impedance adjusting element formed by a first wiring formed on the IC and a second wiring formed on the substrate, wherein the first Changing the number of contacts between the second wiring and the second wiring to change the impedance value of the impedance adjusting element;
A microwave power supply circuit characterized by adjusting the rectification efficiency. By adjusting the impedance of the impedance adjustment element, the rectification efficiency of the microwave power supply circuit due to variations in the characteristics of the rectifier diode can be improved. Having.

According to a fifth aspect of the present invention, there is provided the microwave power supply circuit according to the first, second or third aspect, wherein the capacitor is used as an impedance adjusting element. Using a capacitor as
By appropriately adjusting the capacitance value, it is possible to adjust and improve the deterioration of the rectification efficiency of the microwave power supply circuit due to the variation in characteristics of the rectifier diode and the variation in mounting with a simple circuit configuration.

According to a sixth aspect of the present invention, there is provided the microwave power supply circuit according to the first, second, third or fourth aspect, wherein the spiral inductor is used as an impedance adjusting element. By using a spiral inductor as an adjusting element and appropriately adjusting the inductance value, the simple circuit configuration has the effect of adjusting and improving the deterioration of the rectification efficiency of the microwave power supply circuit due to the characteristic variation of the rectifier diode and the mounting variation. .

According to a seventh aspect of the present invention, there is provided a moving object identification apparatus characterized by using the microwave power supply circuit according to the first to sixth aspects. Also has a microwave power supply circuit with high rectification efficiency,
The transponder has a function of realizing a small and light transponder capable of obtaining sufficient power from a signal from the interrogator, and a mobile identification device capable of communicating in a wide area using the transponder.

According to an eighth aspect of the present invention, there is provided a method of manufacturing the microwave power supply circuit according to the third aspect,
Adjustment of the distance between the IC and the substrate is performed by the IC and the substrate.
And a method for manufacturing a microwave power supply circuit, characterized in that the method is carried out by applying pressure when mounting the device.
It is an easy method to control the impedance of the impedance adjustment element by the pressing strength at the time of C mounting.
In addition, it has the effect of adjusting and improving the deterioration of the rectification efficiency of the microwave power supply circuit due to the characteristic variation at the time of mounting.

According to a ninth aspect of the present invention, there is provided a method of manufacturing the microwave power supply circuit according to the fourth aspect, comprising:
The method of manufacturing a microwave power supply circuit according to claim 1, wherein the number of contacts between the first wiring and the second wiring is adjusted by a pressing strength when mounting the IC.
An easy method of controlling the impedance of the impedance adjusting element by the applied pressure during mounting has the effect of adjusting and improving the deterioration of the rectification efficiency of the microwave power supply circuit due to variations in the characteristics of the IC and the mounting.

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG.

(Embodiment 1) Hereinafter, Embodiment 1 will be described with reference to FIG. FIG. 1 is a circuit diagram of a microwave power supply circuit according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 102 denotes a microwave receiving antenna; 103, a matching circuit connected to the antenna 102; 108, a rectifying circuit for performing half-wave rectification; It comprises an adjustment capacitor 105 arranged. 106 is a low-pass filter unit, and 107 is an output terminal of the microwave power supply circuit.

For example, the antenna 102 has a microstrip structure in which a pattern is formed on the substrate 101.
The matching circuit unit 103 includes the antenna 102 and the rectifier circuit unit 10.
8, and is composed of a distributed constant line or an inductor 103a or a capacitor 103b of a chip component. The low-pass filter 106 smoothes the signal rectified by the diode 104.

In the above configuration, the antenna 102 receives a radio wave radiated from a device not shown, for example, an interrogator, and supplies the radio wave to the rectifier circuit unit 108 via the matching circuit unit 103. In the rectifier circuit unit 108, the microwave is rectified by the diode 104 and passed through the low-pass filter unit 106 so that DC power can be obtained at the output terminal 107.

In order to improve the efficiency of the microwave power supply circuit, a matching circuit 1 corresponding to the characteristics of the diode 104 is required.
It is necessary to input the radio wave received by the antenna 102 to the rectifier circuit unit 108 with low loss. However, the capacitance between the terminals of the diode 104 has large variations among the individual elements. FIG.
This is an analysis of the rectification efficiency of a microwave power supply circuit in which the matching circuit unit 103 is adjusted assuming a half-wave rectifier circuit using a 1 pF diode 104 when the inter-terminal capacitance is varied. From FIG. 2, it can be seen that the rectification efficiency is greatly deteriorated due to a variation of ± 0.05 pF with respect to the terminal capacitance of 0.1 pF. The reason for this is that the matching with the antenna 102 shifts due to the fluctuation of the inter-terminal capacitance, and the mismatch loss increases.

As a countermeasure, the inductor 1 of the matching circuit 103 responds to the variation in the capacitance between the terminals of the diode 104.
03a and capacitor 103b need to be adjusted,
Depending on the characteristics of the individual diode 104, the inductor 103
It is not easy to adjust the two values of “a” and the capacitor 103b, which is a cause that sufficient characteristics cannot be obtained at the time of mass production as well as at the time of small-scale trial production.

The adjustment capacitor 105 is a diode 1
The capacitor is connected between the anode terminal and the cathode terminal of the transistor 04, and the capacitance is changed to correct the deviation of the matching state with respect to the variation in the capacitance between terminals. That is, the matching circuit unit 103 is configured with the standard value or the average value of the inter-terminal capacitance, and when the inter-terminal capacitance changes with respect to this value, only the value of the adjustment capacitor 105 is adjusted according to the degree of the change. This prevents deterioration of the rectification efficiency. The capacitance of the adjustment capacitor 105 is
For example, it is 0 pF to 0.5 pF.

As described above, the adjusting capacitor 10 connected between the anode terminal and the cathode terminal of the rectifying diode 104
5 is provided, and only the capacitance value is adjusted, thereby providing a microwave power supply circuit capable of easily adjusting and improving the deterioration of the rectification efficiency due to the characteristic variation of the diode 4. Is obtained.

(Embodiment 2) Hereinafter, Embodiment 2 will be described with reference to FIG. FIG. 3 is a circuit diagram of a microwave power supply circuit according to Embodiment 2 of the present invention.

In FIG. 3, the rectifier circuit unit 308 includes a rectifier diode 304 having an anode grounded, and an adjusting capacitor 305 disposed in parallel with the diode 304. This embodiment differs from the first embodiment in that the anode end of the rectifier diode 304 is grounded, thereby eliminating the conversion loss due to the series resistance component of the rectifier diode 304.

Conventionally, the rectifier circuit 303 according to this configuration is
Not only variations in the capacitance between the terminals, but also variations in the mounting state of the ground-side terminal of the diode 304 and the influence of the ground pattern shape change the characteristics of the diode 304, and the matching circuit 303 needs to be adjusted after the diode 304 is mounted. was there. However, it is not easy to adjust the two values of the inductor 303a and the capacitor 303b for each individual substrate, and this is a cause that sufficient characteristics cannot be obtained at the time of mass production as well as at the time of trial production.

Therefore, in the present configuration, the adjusting capacitor 305 is connected in parallel with the diode 304, and by changing this capacitance, the deviation of the matching state due to the influence of the capacitance between the terminals and the mounting state and the shape of the ground pattern is corrected. By adjusting only the value of the adjustment capacitor 305, the rectification efficiency is prevented from deteriorating. The capacitance of the adjusting capacitor 305 is, for example, 0 pF to 0.5 pF.

As described above, by providing the adjusting capacitor 305 in parallel with the diode 304 and adjusting only the capacitance value, a microwave power supply circuit capable of easily adjusting and improving the deterioration of the rectification efficiency is realized. This has the advantageous effect of being able to do so.

(Embodiment 3) Hereinafter, Embodiment 3 will be described with reference to FIGS. FIG. 4 is a sectional structural view of a transponder for a moving object identification device according to a fourth embodiment of the present invention, and FIG. 5 is a schematic mounting diagram.

4 and 5, reference numeral 401 denotes an IC,
2 is a transponder board, 403 is a capacitor for adjustment, and IC
The electrode 404 is provided on the side of the transponder and the electrode 405 is provided on the transponder substrate side. Reference numeral 406 denotes a test terminal used for adjustment, and 408 denotes a bump. The difference between the third embodiment and the first embodiment is that the method of adjusting the adjustment capacitor 403 is described by showing a specific structure. Other configurations and functions are the same as those described in the first embodiment.

The IC 401 is flip-chip mounted on the transponder substrate 402, and a parallel plate type capacitor 403 for adjustment is constituted by the IC side electrode 404 and the substrate side electrode 405. At the time of mounting / adjustment, a signal is input from a test terminal 509, and a matching state of the rectifier circuit is determined from an output terminal 507 based on a test signal, for example, rectified DC power.
The capacitance of the adjustment capacitor 403 is adjusted by changing the height of the bump 408 by changing the pressing state of No. 1 to adjust and improve the deterioration of the conversion efficiency due to the deviation of the matching state. For example, if the electrodes 404 and 405 are 250 μm square and the dielectric constant of the sealing material is 5, the bump height is changed from 60 to 20 μm so that the capacitance of the adjustment capacitor 403 is 0.2 μm.
It can be from 0.05 pF to 0.15 pF.

As described above, by changing the capacitance of the adjusting capacitor 403 according to the pressurized state when the IC 401 is mounted, a microwave power supply circuit capable of easily adjusting and improving the deterioration of the rectification efficiency can be realized. The advantageous effect that it can be obtained is obtained.

In the above description, the adjustment capacitor 403 is formed by providing electrodes on the IC 401 and the transponder substrate 402. However, the adjustment capacitor 403 is installed on either the IC 401 or the transponder substrate 402. Alternatively, the capacitance value of the adjusting capacitor may be changed by changing the interval between the adjusting unit and the electrode, for example, the electrode depending on the pressurized state at the time of mounting the IC.

Although the above description has been made for use in individual adjustment, the diode whose characteristics have been extracted in advance may be used to absorb the influence of variation between lots.

Embodiment 4 Hereinafter, Embodiment 4 will be described with reference to FIG. FIG. 6 is a sectional structural view of a transponder for a moving object identification device according to Embodiment 4 of the present invention.

In FIG. 6, 601 is an IC, 602 is a transponder board, 603 is an adjustment wiring, and 605 is an adjustment spiral inductor. The difference between the fourth embodiment and the first embodiment is that a spiral inductor 605 and a plurality of bumps 604 having different heights are used for adjustment, and a specific structure is shown and described for the adjustment method. It is a point. Other configurations and functions are the same as those described in the first embodiment.

The IC 601 is flip-chip mounted on the transponder board 602. At this time, a signal is input from the test terminal 709, and a test signal from the output terminal 707, for example, the rectifier circuit 703 is supplied based on the rectified DC power. Determine the matching state. To reduce inductance 605, use IC60
1 is pressed to crush the bumps 608, and the adjustment wiring 6
By connecting the bump 604a of 03 to the spiral inductor 605, a part of the wiring of the inductor 605 can be short-circuited. In order to further reduce the pressure, if the pressure is continued and the bump 604b is also connected, the inductance value is adjusted, and the deterioration of the conversion efficiency due to the deviation of the matching state is adjusted and improved.

As described above, by changing the inductance value of the spiral inductor 605 depending on the pressurized state when the IC 601 is mounted, a microwave power supply circuit capable of easily adjusting and improving the deterioration of the rectification efficiency is realized. This has the advantageous effect of being able to do so.

Although bumps 604 having different heights are used in FIG. 6, a plurality of bumps having the same height may be used.

Embodiment 5 Hereinafter, Embodiment 3 will be described with reference to FIG. FIG. 8 is a schematic block diagram of a moving object identification device according to Embodiment 5 of the present invention.

In FIG. 8, 820 is an interrogator, and 815 is a transponder. A first antenna 802 of the transponder 830,
Matching circuit section 803, diode 804, adjustment capacitor 805, and low-pass filter section 806 have the same configuration and function as the microwave power supply circuit described in the first embodiment of FIG. 810 is a second antenna that reflects the radio wave radiated from the interrogator 820, and 811 is the second antenna 81.
Modulator 812 connected to the low-pass filter unit 8
Transponder control unit that operates by obtaining power supply power from the output of
Reference numeral 813 denotes a memory connected to the transponder control unit 812.

Reference numeral 821 denotes a transmitting / receiving antenna that radiates radio waves from the interrogator 820 and receives reflected radio waves from the transponder 815, 822 denotes a circulator connected to the transmitting / receiving antenna, and 823 denotes a transmitting unit that outputs a transmission signal to the transmitting / receiving antenna. , 824 is a synthesizer unit that generates a signal corresponding to the carrier frequency of the transmission unit composed of a VCO or the like, 8
25 is a transponder 815 connected to the circulator 822
A demodulation unit 826 demodulates a reflected signal from the transmission unit 826.
3, an interrogator control unit connected to the demodulation unit 825 and the synthesizer unit 824.

The operation of the above configuration will be described below. The transponder 815 is carried by a person or attached to a mobile object. In this transponder 815, information of a person or a moving body possessed in advance is stored in the memory 813. The interrogator 820 is fixedly installed. For example, when the interrogator 820 is started, the interrogator control unit 826 controls the synthesizer unit 824.
, And a signal of a predetermined frequency is
Output more. Upon receiving this signal, the transmitting unit 823 radiates an unmodulated radio wave in the microwave band amplified to a predetermined output from the transmitting / receiving antenna 821 via the circulator 822.

Transponder 815 that has moved in the vicinity of transmitting / receiving antenna 821 receives the radio wave radiated from interrogator 820, and obtains DC power efficiently by the microwave power supply circuit described in the first embodiment. With this power, the transponder control unit 81
2 and the like start operating. The transponder control unit 12 modulates the modulator 811 according to information stored in the memory 813 in advance.
Is operated to modulate and reflect the unmodulated wave radio wave radiated from the interrogator 820 by the second antenna 10. This modulation operation is performed, for example, according to the information in the memory 813.
By changing the matching condition of the second antenna 810 and changing the intensity and phase of the reflected signal, this can be realized.

The modulated reflected signal from transponder 815 is received by transmission / reception antenna 821 of interrogator 820, demodulated by demodulator 825 via circulator 822, and stored in memory 813 of transponder 815 by interrogator controller 826. Obtain information stored in advance.

By using the microwave power supply circuit described in Embodiment 1 for the transponder 815, for example, the first antenna 80
The diode 804 operates even at a weak input power of about 1 mW as the reception electric field strength of No. 2 and the DC power can be obtained with high efficiency by the adjusting capacitor 805. If the transmission power of the interrogator 820 is 300 mW and the antenna gain of the transmission / reception antenna 821 is about 15 dBi, the reception power of 1 mW is located at a position about 1 m away from the interrogator 20.

For example, in a system in which such a transponder 815 is arranged on articles of various shapes moving on a belt conveyor and is identified from the interrogator 820, the transponder 815 is also used.
Since the operating range of the object is as long as about 1 m, it is possible to realize an easy-to-use moving object identification device that can follow a change in the distance between the interrogator 820 and the responder 815 according to the size of the article.

In the above configuration, the transponder 815 is the interrogator 8
Although it is a configuration in which information from the device 20 cannot be obtained, a demodulation circuit is connected to the first antenna 802 or the second antenna 810, and an operation control function according to the demodulated signal is added to the transponder control unit 812. Is also good. Further, although a configuration having two antennas, the first antenna 802 and the second antenna 810, is illustrated as the transponder 815, one antenna may be shared. Conversely, a configuration having a transmission / reception antenna 821 for both transmission and reception is shown as the interrogator 820 antenna, but separate configurations may be used.

As described above, the transponder 815 and the interrogator 820 provided with the microwave power supply circuit described in the first to fourth embodiments.
And the interrogator 82
It is possible to supply the power required to operate the electronic circuit in the transponder 815 to the transponder 8150 away from 0, and it is possible to lengthen the reading distance of the information of the transponder 815 by the interrogator 820. This has an advantageous effect that a mobile object identification device that is easier to use can be realized.

[0053]

As described above, according to the present invention, by adjusting only the value of the adjusting capacitor connected in parallel with the diode, the deterioration of the rectification efficiency according to the characteristic variation of the diode can be easily improved. The advantageous effect that a wave feeding circuit can be realized is obtained.

Further, by configuring a transponder using this microwave power supply circuit configuration, it is possible to extend the readout distance of the information of the transponder by the interrogator, and to realize a more easy-to-use mobile object identification device. The advantageous effect described above can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a microwave power supply circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing an effect of the microwave power supply circuit according to the embodiment of the present invention;

FIG. 3 is a circuit diagram of a microwave power supply circuit according to an embodiment of the present invention.

FIG. 4 is a sectional view of a mounting portion of the microwave power supply circuit according to the embodiment of the present invention;

FIG. 5 is a circuit diagram of a microwave power supply circuit according to an embodiment of the present invention.

FIG. 6 is a sectional view of a mounting portion of the microwave power supply circuit according to the embodiment of the present invention;

FIG. 7 is a circuit diagram of a microwave power supply circuit according to an embodiment of the present invention.

FIG. 8 is a schematic block diagram of a moving object identification device according to an embodiment of the present invention.

FIG. 9 is a circuit diagram of a main part of a conventional transponder for a moving object identification device

[Explanation of symbols]

 101 Substrate 102 Antenna 103 Matching Circuit 104 Diode 105 Adjustment Capacitor 106 Low Pass Filter 107 Output Terminal 108 Matching Circuit 401 IC 402 Substrate 403 Adjustment Capacitor 404 IC Side Electrode 405 Board Side Electrode 408 Bump 509 Test End 603 Adjustment Wiring for adjustment 605 Spiral inductor for adjustment 802 First antenna 803 Matching circuit section 804 Rectification circuit section 806 Low-pass filter 810 Second antenna 811 Modulator 812 Transponder control section 813 Memory 814 Power line 815 Transponder 820 Interrogator 821 Transmitting / receiving antenna 822 Circulator 823 Transmitter 824 Synthesizer 825 Demodulator 826 Interrogator controller 901 Substrate 902 Microstrip line 903 Radiating element 904a Dio 904b diode

Claims (9)

[Claims] An antenna for receiving microwaves, a rectifying element for rectifying the received microwaves, an impedance adjusting element connected in parallel with the rectifying element, and matching the rectifying element and the antenna. A matching circuit, having a low-pass filter for smoothing the output rectified by the rectifying element, connecting the matching circuit to a feeding end of the antenna, and connecting one end of the rectifying element to the matching circuit;
A microwave power supply circuit configured to connect the other end to the low-pass filter, to change an impedance value of the impedance adjusting element according to a variation in the rectifying element, and to keep rectification efficiency constant. . 2. An antenna for receiving a microwave, a rectifying element for rectifying the received microwave, an impedance adjusting element connected in parallel with the rectifying element, and matching the rectifying element and the antenna. A matching circuit, and a low-pass filter for smoothing the output rectified by the rectifying element, connecting the matching circuit to a feeding end of the antenna, and connecting one end of the rectifying element to the matching circuit and the low-pass filter. A microwave connected to a pass filter and grounded at the other end, wherein the rectifying efficiency is kept constant by changing the impedance value of the impedance adjusting element according to the variation and the mounting variation of the rectifier element. Power supply circuit. 3. A substrate on which at least an antenna for receiving a microwave is formed, a rectifying element mounted on the substrate by flip-chip and rectifying the received microwave, and a matching circuit for matching the antenna with the rectifying element. And an impedance-adjusting element whose impedance value changes depending on the distance between the IC and the substrate, wherein the rectification efficiency is adjusted by changing the impedance value of the impedance-adjusting element. Microwave power supply circuit. 4. A substrate on which at least an antenna for receiving a microwave is formed, a rectifying element mounted on the substrate by flip-chip and rectifying the received microwave, and a matching circuit for matching the antenna with the rectifying element. And an impedance adjustment element formed by a first wiring formed on the IC and a second wiring formed on the substrate, wherein the connection between the first wiring and the second wiring is provided. A microwave power supply circuit, wherein the rectification efficiency is adjusted by changing the score to change the impedance value of the impedance adjusting element. 5. The microwave power supply circuit according to claim 1, wherein a capacitor is used as an impedance adjusting element. 6. The method according to claim 1, wherein the spiral inductor is used as an impedance adjusting element.
The microwave power supply circuit according to 2, 3, or 4. 7. A moving object identification device using the microwave power supply circuit according to claim 1. 8. The method of manufacturing a microwave power supply circuit according to claim 3, wherein the distance between the IC and the substrate is adjusted.
A method for manufacturing a microwave power supply circuit, wherein the method is performed by applying a pressure to the IC and the substrate when the IC is mounted. 9. The method of manufacturing a microwave power supply circuit according to claim 4, wherein the number of contacts between the first wiring and the second wiring is adjusted by a pressing strength when the IC is mounted. A method of manufacturing a microwave power supply circuit.