Reflection microwave energy recovery method and device

Abstract

The invention discloses a method and device for recovering reflected microwave energy, and relates to the technical field of microwave energy recovery, and the device is used for replacing a traditional water load in a high-power microwave system so as to recover the reflected microwave energy. The microwave energy utilization system comprises a circulator, a microwave source connected with a first port of the circulator and load equipment connected with a second port of the circulator, and the recycling device comprises a multi-path power divider and a plurality of dynamic rectifying circuits which are connected to a third port of the circulator. The multi-path power divider comprises a plurality of output ports, the number of the output ports is the same as that of the dynamic rectification circuits, and the output ports are matched with the dynamic rectification circuits one by one. Reflected microwave energy is converted into direct-current energy to be stored or used by other equipment; the device consists of a multi-path power divider and a plurality of rectifying circuits, and can effectively collect reflected microwave energy in a wide dynamic range so as to improve the utilization efficiency of the energy.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave energy recovery, and more specifically to the technical field of a method and device for recovering reflected microwave energy. Background Art

[0002] With the rapid development of technology, microwave energy has currently been widely applied in many important fields and plays an irreplaceable role. For example, in microwave heating, it has the characteristics of efficient and uniform heating and is widely used in food processing and industrial material preparation; in microwave plasma, it is used for semiconductor etching and material surface modification; in microwave medical treatment, tumors can be accurately targeted through ablation technology, and medical equipment can also be disinfected; in the communication field, microwave is relied on to achieve information transmission between satellite communications and base stations, realizing global information interaction.

[0003] However, during the utilization of microwave, the load impedance may change greatly. For example, an increase in temperature will cause a change in the dielectric constant of the load. Therefore, in traditional microwave systems, in order to prevent high-power reflection caused by impedance mismatch from damaging the microwave source, a water load is generally used to absorb the reflected microwave energy. However, all these reflected energies are absorbed by water and converted into heat, without being effectively utilized, thus causing energy waste. Summary of the Invention

[0004] The purpose of the present invention is to solve the technical problem that in the existing microwave system, a water load is used to absorb the reflected microwave energy, and the reflected energy is not effectively utilized, resulting in energy waste. The present invention provides a method and device for recovering reflected microwave energy. It is used to replace the water load and convert the reflected microwave energy into direct current energy for storage or use by other devices. The device is composed of a multi-way power divider and a plurality of rectification circuits, and can effectively collect the reflected microwave energy within a wide dynamic range.

[0005] The present invention specifically adopts the following technical solutions to achieve the above purpose:

[0006] One aspect of the present invention provides a device for reflecting microwave energy, which is used in a microwave energy utilization system. The microwave energy utilization system includes a circulator, a microwave source connected to the first port of the circulator, and a load device connected to the second port of the circulator. The recovery device includes a multi-way power divider and a plurality of dynamic rectification circuits connected to the third port of the circulator. The multi-way power divider includes a plurality of output ports, and the number of the output ports is the same as the number of the dynamic rectification circuits and they are in one-to-one correspondence.

[0007] Specifically, in order to replace the water load and improve the energy utilization rate, a recovery device of the usage scheme is used. The dynamic range of the recovery device depends on the number of port outputs of the power divider and the dynamic range capability of the rectifier circuit.

[0008] A circulator is a multi-port device with the characteristic of unidirectional transmission of high-frequency signal energy. It usually has three ports. Signals can be transmitted from the first port to the second port, then from the second port to the third port, and finally from the third port back to the first port. Conversely, it is isolated. The circulator plays an isolation role between the output end of the high-frequency power amplifier and the load, protecting the high-power microwave source from the influence of load changes.

[0009] A power divider is a device that divides the energy of an input signal into two or more outputs with equal or unequal energy. It can also combine the energy of multiple signals into one output, and in this case, it can also be called a combiner. A power divider is a passive power splitter, and a waveguide power divider or a microstrip power divider is used according to the power size.

[0010] In one embodiment, the dynamic rectifier circuit is a wide-power rectifier circuit structure, and the wide-power rectifier circuit structure includes an input part, a microwave rectification part, and a DC output part;

[0011] The microwave rectification part includes two rectification branches arranged in parallel. The two rectification branches are the first rectification branch and the second rectification branch respectively. The first rectification branch is used for rectification, and the second rectification branch is used to compensate the dynamic impedance of the second rectification branch to improve the matching performance of the circuit. The first rectification branch and the second rectification branch are connected to the main transmission line between the output end of the microwave input part and the input end of the DC output part.

[0012] Specifically, the designed wide-power rectifier circuit structure is as Figure 2 shown. The wide-power rectifier circuit structure has two parallel rectification branches. Among them, the first rectification branch plays a key rectification role in the entire power range, and the second rectification branch is mainly used to compensate the dynamic impedance of the second rectification branch to improve the matching performance of the circuit. In addition, by paralleling the two branches, the power capacity of the circuit can also be improved, and to a certain extent, the applicable range of the circuit at high power can be broadened.

[0013] The design purpose of the wide-power rectifier circuit structure is that the impedance of the load device may change dynamically during the process of absorbing microwaves. Therefore, the reflected microwave energy is also uncertain, which may be high-power energy or low-power energy. In order to ensure that the entire recovery device has good stability in a wide power range, a wide-power rectifier circuit structure that can be used for high power is designed.

[0014] In one embodiment, the first rectifier branch includes a high-power rectifier diode D 1 , and the high-power rectifier diode D 1 is grounded through a ground transmission line TL3;

[0015] The second rectifier branch includes a high-power rectifier diode D 2 , and the high-power rectifier diode D 2 is grounded through a ground transmission line TL4. The first rectifier branch and the second rectifier branch are connected in parallel;

[0016] The ground transmission line TL3 and the ground transmission line TL4 are used to compensate the imaginary part of the diode and can suppress even harmonics; TL5 is a section of series transmission line for impedance transformation. By adjusting its length and width, the impedance of the second rectifier branch can compensate the impedance of the first rectifier branch.

[0017] Specifically, both TL3 and TL4 are ground transmission lines and can be equivalent to an inductor. They are mainly used to compensate the imaginary part of the diode and also have the function of suppressing even harmonics. TL5 is a section of series transmission line for impedance transformation. By adjusting its length and width, the impedance of the second rectifier branch can compensate the impedance of the first rectifier branch, so that the real part and the imaginary part of the overall impedance after the two branches are connected in parallel can be more stable within a wide power range, thereby achieving a good impedance matching effect within a wide dynamic range.

[0018] In one embodiment, the input part performs a DC blocking process on the received microwave energy signal through a DC blocking capacitor C1 to prevent the rectified DC signal from flowing back (backfeeding) into the microwave source. An impedance matching network is provided on the input part.

[0019] In one embodiment, the impedance matching network includes a series transmission line TL1 and a parallel transmission line TL2. The series transmission line TL1 is connected in series in the input part and is located between the microwave source and the DC blocking capacitor C1. The parallel transmission line TL2 is connected in parallel between the DC blocking capacitor C1 and the series transmission line TL1. The series transmission line TL1 and the parallel transmission line TL2 form an L-shaped network for impedance matching.

[0020] In one embodiment, the DC output part includes a series transmission line TL6 and a load. One end of the series transmission line TL6 is connected to the output end of the microwave rectification part, and the other end is connected to the load. The other end of the load is grounded.

[0021] In one embodiment, a filter capacitor C 2 is further included. The filter capacitor C 2 is connected in parallel with the load. The end of the filter capacitor C 2 is grounded. The series transmission line TL6 is connected to the filter capacitor C 2Together, they form a direct-through filter circuit, which is connected to the output terminal of the filter rectification part through the filter capacitor C2 to filter out the fundamental wave and then output DC energy.

[0022] Specifically, the series transmission line TL6 and the filter capacitor C 2 Together form a direct-through filter circuit, so that the load R L can obtain a stable output voltage. The load resistance R L has a resistance value of 110 Ω.

[0023] In one embodiment, the high-power rectifier diode D 1 and the high-power rectifier diode D 1 are both high-power rectifier diodes of model HSMS270C.

[0024] The second aspect of the present invention provides a method for recovering reflected microwave energy. Using the above-mentioned device for reflecting microwave energy, it includes the following steps:

[0025] S1. Connect a multi-way power divider to the third port of the circulator to evenly divide the reflected microwave energy into several parts and output it;

[0026] S2. Then connect a rectification circuit to each output port of the power divider to convert the microwave energy into DC energy to supply power to the load or store it. The overall system device is as Figure 1 shown;

[0027] S3. The number of output ports of the power divider is determined by the peak value of the reflected power. The greater the reflected power, the more output ports should be, to ensure that the rectification circuit can work properly.

[0028] The beneficial effects of the present invention are as follows:

[0029] 1. The present invention converts the reflected microwave energy into DC energy for storage or use by other devices. The device consists of a multi-way power divider and multiple rectification circuits, and can effectively absorb the reflected high-power microwave.

[0030] 2. This device replaces the traditional water load device, avoiding all the reflected microwave energy being converted into heat, thereby improving the energy utilization rate.

[0031] 3. In the wide - power rectifier circuit structure, TL3 and TL4 are both ground transmission lines and can be equivalent to an inductor. They are mainly used to compensate for the imaginary part of the diode and also have the function of suppressing even - order harmonics. TL5 is a section of series transmission line for impedance transformation. By adjusting its length and width, the impedance of the second rectifier branch can compensate for the impedance of the first rectifier branch, so that the real and imaginary parts of the overall impedance after the two branches are connected in parallel can be more stable within a wide power range, thereby achieving a good impedance matching effect within a wide dynamic range.

[0032] 4. The proposed rectifier circuit is applicable to a higher power range compared to other rectifier circuits and can be combined with a multi - way power divider to achieve microwave energy harvesting at high power. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0034] Figure 1 It is a schematic structural diagram of the present invention.

[0035] Figure 2 It is a schematic diagram of the principle of the wide - dynamic rectifier circuit.

[0036] Figure 3 It is a layout of the wide - dynamic rectifier circuit.

[0037] Figure 4 It is a schematic diagram of the simulation result of the efficiency of the wide - dynamic rectifier circuit layout varying with the input power.

[0038] Figure 5 It is a schematic diagram of the simulation result of S11 of the wide - dynamic rectifier circuit layout varying with the input power. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] To make the technical problems, technical solutions, and technical effects of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0040] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0041] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings. In addition, the terms "first", "second", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0042] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "inner", "outer", "upper", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0043] Embodiment 1

[0044] As Figure 1 shown, this embodiment provides a device for reflecting microwave energy for a microwave energy utilization system. The microwave energy utilization system includes a circulator, a microwave source connected to the first port of the circulator, and a load device connected to the second port of the circulator. The recovery device includes a multi-way power divider connected to the third port of the circulator and a plurality of dynamic rectifier circuits. The multi-way power divider includes a plurality of output ports, and the number of output ports is the same as the number of dynamic rectifier circuits and they are in one-to-one correspondence.

[0045] Specifically, in order to replace the water load and improve the energy utilization rate, the recovery device of the proposed solution is used. The dynamic range of the recovery device depends on the number of port outputs of the power divider and the dynamic range ability of the rectifier circuit.

[0046] A circulator is a multi-port device with the characteristic of unidirectional transmission of high-frequency signal energy. It usually has three ports. Signals can be transmitted from the first port to the second port, then from the second port to the third port, and finally from the third port back to the first port. Conversely, it is isolated. The circulator plays an isolation role between the output end of the high-frequency power amplifier and the load, protecting the power amplifier from the influence of load changes.

[0047] A power divider is a device that divides the energy of an input signal into two or more output signals with equal or unequal energy, or conversely, combines the energy of multiple input signals into one output signal, in which case it can also be called a combiner.

[0048] Embodiment 2

[0049] As Figure 1 shown, this embodiment provides a device for reflecting microwave energy for a microwave energy utilization system. The microwave energy utilization system includes a circulator, a microwave source connected to the first port of the circulator, and a load device connected to the second port of the circulator. The recovery device includes a multi-way power divider connected to the third port of the circulator and a plurality of dynamic rectifier circuits. The multi-way power divider includes a plurality of output ports, and the number of output ports is the same as the number of dynamic rectifier circuits and they are in one-to-one correspondence.

[0050] The dynamic rectifier circuit is a wide-power rectifier circuit structure, which includes an input part, a microwave rectification part, and a DC output part;

[0051] The microwave rectification part includes two rectification branches connected in parallel. The two rectification branches are the first rectification branch and the second rectification branch respectively. The first rectification branch is used for rectification, and the second rectification branch is used to compensate the dynamic impedance of the second rectification branch to improve the matching performance of the circuit. The first rectification branch and the second rectification branch are connected to the main transmission line between the output end of the microwave input part and the input end of the DC output part.

[0052] Specifically, the designed wide-power rectifier circuit structure is as Figure 2 shown. The wide-power rectifier circuit structure has two parallel rectification branches. Among them, the first rectification branch plays a key rectification role in the entire power range, and the second rectification branch is mainly used to compensate the dynamic impedance of the second rectification branch to improve the matching performance of the circuit. In addition, by paralleling the two branches, the power capacity of the circuit can also be increased, and to a certain extent, the applicable range of the circuit at high power can be broadened.

[0053] The design purpose of the wide-power rectifier circuit structure: Since the change of the load impedance cannot be determined, the reflected microwave energy cannot be determined either. It may be high-power energy or low-power energy. In order to ensure that the entire recovery device has good stability in a wide power range, a wide-power rectifier circuit structure that can be used for high power is designed.

[0054] Embodiment 3

[0055] This embodiment is a further optimization based on Embodiment 2. Specifically:

[0056] The first rectification branch includes a high-power rectifier diode D 1 , and the high-power rectifier diode D 1 is grounded through a ground transmission line TL3;

[0057] The second rectification branch includes a high-power rectifier diode D 2 , and the high-power rectifier diode D 2 is grounded through a ground transmission line TL4. The first rectification branch and the second rectification branch are connected in parallel;

[0058] The ground transmission line TL3 and the ground transmission line TL4 are used to compensate for the imaginary part of the diode and can suppress even harmonics; TL5 is a section of series transmission line for impedance transformation. Adjust its length and width so that the impedance of the second rectification branch can compensate for the impedance of the first rectification branch.

[0059] Specifically, TL3 and TL4 are both ground transmission lines and can be equivalent to an inductor. They are mainly used to compensate for the imaginary part of the diode and also have the function of suppressing even harmonics. TL5 is a section of series transmission line for impedance transformation. Adjust its length and width so that the impedance of the second rectification branch can compensate for the impedance of the first rectification branch, making the real part and the imaginary part of the overall impedance more stable within a wide power range after the two branches are connected in parallel, so as to achieve a good impedance matching effect within a wide dynamic range.

[0060] Embodiment 4

[0061] This embodiment is further optimized on the basis of Embodiment 3. Specifically:

[0062] The input part performs a DC blocking process on the received microwave energy signal through a DC blocking capacitor C1 to prevent the rectified DC signal from flowing back (backfeeding) into the microwave source. An impedance matching network is provided on the input part.

[0063] The impedance matching network includes a series transmission line TL1 and a parallel transmission line TL2. The series transmission line TL1 is connected in series in the input part and is located between the microwave source and the DC blocking capacitor C1. The parallel transmission line TL2 is connected in parallel between the DC blocking capacitor C1 and the series transmission line TL1. The series transmission line TL1 and the parallel transmission line TL2 form an L-shaped network for impedance matching.

[0064] The DC output part includes a series transmission line TL6 and a load. One end of the series transmission line TL6 is connected to the output end of the microwave rectification part, and the other end is connected to the load. The other end of the load is grounded.

[0065] It also includes a filter capacitor C 2 , and the filter capacitor C 2 is connected in parallel with the load. The end of the filter capacitor C 2 is grounded. The series transmission line TL6 and the filter capacitor C2 They together form a direct-through filter circuit, which is connected to the output terminal of the filter rectification part through the filter capacitor C2 to filter out the fundamental wave and then output DC energy.

[0066] Specifically, the series transmission line TL6 and the filter capacitor C 2 together form a direct-through filter circuit, so that the load RL can obtain a stable output voltage. The resistance value of the load resistor RL is 110 Ω.

[0067] Experimental results:

[0068] A Rogers 4003C board with a thickness of 0.813 mm was selected to design a wide-power rectifier circuit structure that can operate at a frequency of 2.45 GHz. The designed layout is as Figure 3 shown. Figure 4 is the simulation result of the efficiency of the rectifier circuit varying with the input power. It can be seen that in the input power range of 24 - 42 dBm, the rectification efficiency is greater than 60%. In the input power range of 19 - 43 dBm, the rectification efficiency exceeds 50%, and the highest efficiency reaches 78%, indicating that the circuit has the ability to work efficiently in a wide power range. Figure 5 is the simulation result of the S 11 of the rectifier circuit varying with the input power. It can be seen that in the input power range of 18 - 43 dBm, S 11 is less than -10 dB, reflecting the good impedance matching performance of the rectifier circuit.

[0069] Embodiment 5

[0070] This embodiment provides a method for recovering reflected microwave energy. Using the above-mentioned device for reflecting microwave energy, it includes the following steps:

[0071] S1. Connect a multi-way power divider to the third port of the circulator to evenly divide the reflected microwave energy into several parts and output it;

[0072] S2. Then connect a rectifier circuit to each output port of the power divider to convert the microwave energy into DC energy to supply power to the load or store it. The overall system device is as Figure 1 shown;

[0073] S3. The number of output ports of the power divider is determined by the peak value of the reflected power. The greater the reflected power, the more output ports should be, to ensure the normal operation of the rectifier circuit.

Claims

1. A device for reflecting microwave energy, used in a microwave energy utilization system, the microwave energy utilization system comprising a circulator, a microwave source connected to a first port of the circulator, and a load device connected to a second port of the circulator, characterized in that: The recovery device includes a multi-way power distributor connected to the third port of the circulator and a plurality of dynamic rectification circuits. The multi-way power distributor includes a plurality of output ports, the number of the output ports is the same as the number of the dynamic rectification circuits, and they are matched one by one.

2. A device for reflecting microwave energy according to claim 1, characterized in that: The dynamic rectification circuit is a wide power rectification circuit structure, which includes an input part, a microwave rectification part and a DC output part; The microwave rectification part includes two rectification branches arranged in parallel, the two rectification branches are respectively a first rectification branch and a second rectification branch, the first rectification branch is used for rectification, and the second rectification branch is used to compensate for the dynamic impedance of the second rectification branch to improve the matching performance of the circuit, and the first rectification branch and the second rectification branch are connected to the main transmission line between the output end of the microwave input part and the input end of the DC output part.

3. A device for reflecting microwave energy according to claim 2, characterized in that: The first rectifying branch includes a high-power rectifying diode D1, and the high-power rectifying diode D1 is grounded through a grounding transmission line TL3; The second rectifying branch includes a high-power rectifying diode D2, the high-power rectifying diode D2 is grounded through a grounding transmission line TL4, and the first rectifying branch and the second rectifying branch are connected in parallel; The grounded transmission line TL3 and the grounded transmission line TL4 are used to compensate for the imaginary part of the diode and can suppress even harmonics; TL5 is a series transmission line for impedance transformation, and its length and width are adjusted so that the impedance of the second rectifying branch can compensate for the impedance of the first rectifying branch.

4. A device for reflecting microwave energy according to claim 3, characterized in that: The input part performs direct current isolation processing on the received microwave energy signal through the direct current isolation capacitor C1 to prevent the rectified direct current signal from flowing into or backflowing into the microwave source. An impedance matching network is provided on the input part.

5. A device for reflecting microwave energy according to claim 4, characterized in that: The impedance matching network includes a series transmission line TL1 and a parallel transmission line TL2. The series transmission line TL1 is connected in series at the input part and is located between the microwave source and the DC blocking capacitor C1. The parallel transmission line TL2 is connected in parallel between the DC blocking capacitor C1 and the series transmission line TL1. The series transmission line TL1 and the parallel transmission line TL2 form an L-type network for impedance matching.

6. A device for reflecting microwave energy according to claim 5, characterized in that: The DC output part includes a series transmission line TL6 and a load. One end of the series transmission line TL6 is connected to the output end of the microwave rectifying part, and the other end is connected to the load. The other end of the load is grounded.

7. A device for reflecting microwave energy according to claim 6, characterized in that: It also includes a filter capacitor C2, which is connected in parallel with the load, and the end of the filter capacitor C2 is grounded. The series transmission line TL6 and the filter capacitor C2 together form a through filter circuit, which is connected to the output end of the filter and rectifier part through the filter capacitor C2, and outputs DC energy after filtering the fundamental wave.

8. A method for recovering reflected microwave energy according to claim 7, characterized in that: The high-power rectifier diode D1 and the high-power rectifier diode D1 are both high-power rectifier diodes with model HSMS270C.

9. A method for recovering reflected microwave energy, characterized in that: Use the device for reflecting microwave energy as claimed in claim 1.

10. A method for recovering reflected microwave energy according to claim 9, characterized in that: The steps include: S1. Connect a multi-way power divider to the third port of the circulator to evenly divide the reflected microwave energy into several outputs; S2, then connect a rectifier circuit to each output port of the power divider to convert microwave energy into DC energy to power the load or store it; S3. The number of output ports of the power divider is determined by the peak value of the reflected power. The greater the reflected power, the greater the number of output ports should be to ensure that the rectifier circuit can work normally.

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