CN219372298U

CN219372298U - Multisection impedance transformation microwave rectification circuit of diode series connection band stop

Info

Publication number: CN219372298U
Application number: CN202320010267.3U
Authority: CN
Inventors: 黄艳虎; 梁家军; 何鹏; 陈谦; 冯林平; 覃江坡; 林宗晟
Original assignee: Yulin Normal University
Current assignee: Yulin Normal University
Priority date: 2023-01-04
Filing date: 2023-01-04
Publication date: 2023-07-18
Anticipated expiration: 2033-01-04

Abstract

The utility model belongs to the technical field of rectifier circuits, and particularly relates to a multi-section impedance transformation microwave rectifier circuit with diodes connected in series and with resistors, which comprises the following components: a low-pass filter with wide stop band, a Schottky diode, a terminal short-circuit microstrip line and a DC filter matching circuit; the input end of the low-pass filter is connected with the signal source output, and the output end of the low-pass filter is connected with 1 blocking capacitor; the output end of the blocking capacitor is connected with the Schottky diode; the Schottky diode is of the type HSMS-286C and consists of two parallel HSMS-2860 diodes; one of the HSMS-2860 diodes is connected with the direct current filtering matching circuit, and the other HSMS-2860 diode is connected with the terminal short-circuit microstrip line; and a harmonic suppression network is also arranged between the direct current filtering matching circuit and the load at the rectifying output end. The utility model can realize miniaturization and high conversion efficiency and has better market application prospect.

Description

Multisection impedance transformation microwave rectification circuit of diode series connection band stop

Technical Field

The utility model belongs to the technical field of rectifying circuits, and particularly relates to a multi-section impedance transformation microwave rectifying circuit with diodes connected in series and provided with resistors.

Background

The intelligent home and the intelligent city are intelligent, informationized and interconnected with any person and any object by depending on a large number of electronic devices. These electronic devices are limited by the size and weight, and a battery having a large capacity cannot be built in the body, and the battery cannot provide a long-term use of the device because of the use of a battery having a small capacity has been a problem. Self-powered systems are an alternative method of extracting energy from a Radio Frequency (RF) environment by means of radio waves, converting it into a usable dc voltage, thus solving the key problem of the energy supply of the device.

The microwave wireless energy transmission (Microwavewireless power transmission, MWPT) technology is limited by space and environment, has the advantages of sustainability, environmental protection, wide applicability and the like, and has great application prospects in military and civil fields such as space solar power stations, wireless sensor networks, implanted medical equipment, intelligent wearable equipment, unmanned aerial vehicle aerial charging and the like. The microwave wireless energy transmission system mainly comprises four parts of a microwave source, a transmitting antenna, a receiving antenna and a rectifying circuit. The rectifying circuit is an important component in microwave wireless energy transmission, and basically comprises an input filter, a rectifying diode, a direct current filter and a direct current load as shown in fig. 1, and the rectifying circuit converts microwave energy received by an antenna into direct current energy, and the capacity of converting the direct current energy into the direct current energy is called rectifying efficiency or conversion efficiency and is defined as the ratio of output direct current power to received microwave power. The conversion rate of the existing rectifying circuit is low, and in order to improve the conversion rate of the radio frequency energy collecting system, the application provides a multi-section impedance conversion microwave rectifying circuit with a diode series band resistor having a harmonic suppression function, so that miniaturization and high conversion efficiency can be achieved.

The information disclosed in this background section is only for enhancement of understanding of the general background of the utility model and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

Disclosure of Invention

The utility model aims to provide a multisection impedance transformation microwave rectifying circuit with a diode series band resistor, which is miniaturized and has high conversion efficiency.

In order to achieve the above object, the present utility model provides the following technical solutions:

a multi-segment impedance transformation microwave rectifying circuit of diode series bandstop, comprising: a low-pass filter with wide stop band, a Schottky diode, a terminal short-circuit microstrip line and a DC filter matching circuit; the input end of the low-pass filter is connected with the signal source output, and the output end of the low-pass filter is connected with 1 blocking capacitor; the output end of the blocking capacitor is connected with the Schottky diode; the Schottky diode is of the type HSMS-286C and consists of two parallel HSMS-2860 diodes; one of the HSMS-2860 diodes is connected with the direct current filtering matching circuit, and the other HSMS-2860 diode is connected with the terminal short-circuit microstrip line; and a harmonic suppression network is also arranged between the direct current filtering matching circuit and the load at the rectifying output end.

Preferably, the center frequency f is set to 5.8GHz.

Preferably, the signal source input impedance is matched with the diode self impedance; the output end load of the low-pass filter is matched with the impedance of the diode; the self impedance of the load plus diode at the output end of the low-pass filter is matched with the load resistance at the rectifying output end.

Compared with the prior art, the utility model has the following beneficial effects:

(1) The multi-section impedance transformation microwave rectification circuit of the diode series band resistor adopts the HSMS285 Schottky diode to be connected in series on the microstrip line, and the microstrip line compensates the capacitance impedance of the diode at the fundamental frequency to form an open circuit to block the second harmonic, thereby enhancing the power circulation and effectively improving the rectification efficiency.

(2) The improved harmonic suppression network of the direct current output end integrates the common higher harmonic suppression part of the input filter and the output filter to the diode output end, so that higher harmonic is suppressed between the diode and the harmonic filter, fundamental frequency and higher harmonic generated by diode nonlinearity are eliminated, radio frequency backflow is avoided, the whole structure is compact, the loss is smaller, and the rectifying efficiency is effectively improved.

Drawings

FIG. 1 is a schematic diagram of a specific rectifying structure of a conventional rectifying circuit;

FIG. 2 is a graph of the diode self-impedance as a function of power;

FIG. 3 is a block diagram of a rectifying circuit with multiple sections of transmission line matching according to the present utility model;

fig. 4 is a configuration diagram of a rectifying circuit of the present utility model;

FIG. 5 is a graph of rectifying efficiency versus input power for different loads;

FIG. 6 is a simulation graph of a rectifier circuit;

FIG. 7 is a schematic diagram of a rectenna conversion efficiency test system;

fig. 8 is a diagram showing a comparison between a simulation and actual measurement of the return loss of the rectifying circuit.

Detailed Description

The following description of the embodiments of the present utility model will be apparent from the description of the embodiments of the present utility model, which is provided in part, but not in whole. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, are intended to fall within the scope of the present utility model.

In the description of the present utility model, it should be noted that, as the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like are used for convenience of description and simplicity of description, only as to the orientation or positional relationship shown in the drawings, and not as an indication or suggestion that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the utility model.

In the description of the present utility model, it should be noted that unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" should be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be connected between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases to those skilled in the art.

Referring to the drawings, a multi-section impedance transformation microwave rectification circuit of diode series band-stop comprises: a low-pass filter with wide stop band, a Schottky diode, a terminal short-circuit microstrip line and a DC filter matching circuit; the input end of the low-pass filter is connected with the signal source output, and the output end of the low-pass filter is connected with 1 blocking capacitor; the output end of the blocking capacitor is connected with the Schottky diode; the Schottky diode is of the type HSMS-286C and consists of two parallel HSMS-2860 diodes; one of the HSMS-2860 diodes is connected with the direct current filtering matching circuit, and the other HSMS-2860 diode is connected with the terminal short-circuit microstrip line; and a harmonic suppression network is also arranged between the direct current filtering matching circuit and the load at the rectifying output end. Wherein the center frequency f is set to 5.8GHz; the input impedance of the signal source is matched with the impedance of the diode; the output end load of the low-pass filter is matched with the impedance of the diode; the self impedance of the load plus diode at the output end of the low-pass filter is matched with the load resistance at the rectifying output end.

In the embodiment, the HSMS-286 Schottky diode is connected in series on the microstrip line, the microstrip line compensates the capacitance impedance of the diode at the fundamental frequency to form an open circuit to block the second harmonic, and the power circulation is enhanced, so that the rectification efficiency is effectively improved. The microwave rectifying circuit in the embodiment has a compact structure, and when the input power is 17dBm and the direct current load is 680 omega, the RF-DC conversion efficiency of the circuit simulation test is 60.9%; the actual output voltage of the circuit at the position with the transmission distance of 1 meter is 1.003V after the circuit is processed, the voltage output by adjusting the communication distance correspondingly changes, and the maximum output voltage can reach 4.249V. The actual measurement result is relatively consistent with the simulation result, and the rectification efficiency is over 50% within the range of 10-20dBm of the input power.

The specific rectifying structure of the conventional rectifying circuit is shown in figure 1, and consists of an alternating current filtering matching network, a rectifying diode, a low-pass filter and a load resistor. In order to maximize the power transfer between the antenna and the rectifying circuit, a matching network is required.

The diode exhibits a nonlinear characteristic at high power inputs, and the input impedance of the diode varies with the input power. The input impedance was 50Ω at 5.8GHz for the microwave source, and the self impedance of the diode was 71.082-j4.44Ω when the input power (Pin) was 17 dBm. Consider a diode self impedance profile, a capacitive resistive load and a power profile as shown in figure 2.

In order to achieve miniaturization and high conversion efficiency, a novel multi-section transmission line rectifying circuit of the terminal short-circuit microstrip line is designed, and the multi-section transmission line rectifying circuit is shown in a figure 3. The circuit is divided into PartA, partB, partC, partD parts and consists of a low-pass filter, a terminal short-circuit microstrip line matching, a direct-current filtering matching circuit and a harmonic suppression network.

The center frequency f is set to 5.8GHz. Branch one matching: matching the input to a diode; branch and knot two matching: the load of the output end is matched with the diode, the 50 omega of the branch A is matched with 71.082-j4.44 omega, the self impedance of the 71.082-j4.44 omega plus diode is the input impedance of the branch B, and the load impedance of the rectification output end is matched with the load impedance of the rectification output end.

In order to verify the impedance matching process and the accurate matching effect, higher conversion efficiency is obtained, and schematic diagram-layout joint simulation is carried out on the circuit by using ADS2021 simulation software. The dielectric plate used in the rectifying circuit is Rogers4350b material, the dielectric constant is 3.48, the loss angle is 0.017, and the thickness is 1.524mm.

As shown in fig. 4, the rectifying circuit is composed of a blocking capacitor C1, two schottky diodes HSMS-286C connected in parallel, a direct current filter capacitor C2, a harmonic suppression network of a low-pass filter, and a load resistor. In design, capacitor C1 is 60pF and C2 is 22; the load Rload of the current output is 680 Ω. The schottky diode HSMS-286C is composed of two parallel HSMS-2860 diodes.

The rectification efficiency is an important index of the rectification circuit, and is represented by the capability of converting radio frequency energy into direct current power. The specific wireless energy transfer rectification efficiency is obtained through calculation according to the following formula:

wherein: p (P) _out Is the direct current output power; p (P) _in For radio frequency input and power; v (V) _out Is a direct current output voltage; r is R _L Is the load resistance.

To further enhance the ability of the rectifier to operate over a wide input power range, fig. 5 compares the RF-DC conversion efficiency curves under different loads.

As can be seen from the figure, the maximum RF-DC conversion efficiency of 40% occurs at an input power of 17dBm at a load of 200Ω. At a load of 600Ω, a maximum RF-DC conversion efficiency of 60.5% occurs at an input power of 17 dBm.

From the above comparison it can be concluded that the output dc power is mainly dependent on the output voltage and the output load, which is one of the key parameters affecting the overall power efficiency. The circuit load may be adjusted to increase and improve the circuit efficiency of the predefined input power range.

The simulation curve of the rectifying circuit is shown in fig. 6, and it can be seen that at the frequency of 5.8GHz, S11 reaches-24.9 dB, and the rectifying circuit is well matched with the microwave source. The bandwidth of S11< -15dB is 200MHz (5.75-5.95 GHz).

In actual processing test, converting the rectifier circuit in ADS software into a dxf file, and introducing the dxf file into aluminum design software to perform operations such as copper coating, so as to obtain a rectifier circuit real object, wherein the size of a rectifier is 60mm multiplied by 55mm.

The microwave rectifying antenna is taken as a whole, and the antenna and the rectifying circuit are required to be unified for testing. The complete microwave rectenna test system mainly comprises: the structure diagram of the conversion efficiency test of the specific rectifying circuit is shown in figure 7.

In an actual test environment, N5171B of KEYSIGHT is used as a signal source, and is connected with a 5.8G horn antenna through an SMA connector; the receiving end adopts a horn receiving antenna with the same frequency and a rectifying circuit with a complex matching network to be connected through an SMA conversion head, and the direct-current voltage is measured on a resistance load (680 omega) through a voltmeter.

The rectification circuit is tested by using an Agilent N9960A handheld microwave spectrum analyzer, the measuring result and the simulation result of the return loss of the rectification circuit are shown in figure 8, the measured return loss of the rectification circuit at the 5.8G position is 21.2dB, and the measuring result and the simulation result are well matched.

Aiming at the problems of low collection efficiency and the like of a radio frequency energy collection system under the condition of low power, the utility model designs an environment radio frequency energy collection circuit working in a 5.8GHz frequency band. In order to realize the matching of the input impedance of the antenna and the voltage doubling rectifying circuit and a load, an improved impedance compression matching network for splitting the rectifying circuit into 4 parts is provided. In the embodiment, the circuit is simulated by simulation software, and simulation results show that the maximum RF-DC conversion efficiency of the designed rectifier reaches 60.3% when the input power is 17dBm, the actual output voltage of the circuit at the position with the transmission distance of 1 meter is 1.003V after the circuit is processed, the voltage output by adjusting the communication distance correspondingly changes, and the maximum output voltage can reach 4.58V. The miniaturized rectification circuit designed by the utility model can be used for supplying energy to microsystems of miniaturized equipment such as wireless sensors, radio frequency identification cards, pipeline micro robots and the like.

The foregoing descriptions of specific exemplary embodiments of the present utility model are presented for purposes of illustration and description. It is not intended to limit the utility model to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain the specific principles of the utility model and its practical application to thereby enable one skilled in the art to make and utilize the utility model in various exemplary embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the utility model be defined by the claims and their equivalents.

Claims

1. The utility model provides a multisection impedance transformation microwave rectifier circuit of diode series band stop which characterized in that includes: a low-pass filter with wide stop band, a Schottky diode, a terminal short-circuit microstrip line and a DC filter matching circuit; the input end of the low-pass filter is connected with the signal source output, and the output end of the low-pass filter is connected with 1 blocking capacitor; the output end of the blocking capacitor is connected with the Schottky diode; the Schottky diode is of the type HSMS-286C and consists of two parallel HSMS-2860 diodes; one of the HSMS-2860 diodes is connected with the direct current filtering matching circuit, and the other HSMS-2860 diode is connected with the terminal short-circuit microstrip line; and a harmonic suppression network is also arranged between the direct current filtering matching circuit and the load at the rectifying output end.

2. The multi-segment impedance transformation microwave rectifying circuit of diode string bandstop according to claim 1, characterized in that the center frequency f is set to 5.8GHz.

3. The multi-section impedance transformation microwave rectification circuit of diode serial band elimination according to claim 1, wherein the signal source input impedance is matched with the diode self impedance; the output end load of the low-pass filter is matched with the impedance of the diode; the self impedance of the load plus diode at the output end of the low-pass filter is matched with the load resistance at the rectifying output end.