High-power microwave rectifying circuit based on 1*4 power divider

Abstract

The invention discloses a high-power microwave rectifying circuit based on a 1 * 4 power divider. Firstly, a Si-based Schottky diode HSMS-270C (BV = 25V) with relatively high reverse breakdown voltage is selected, and one diode packaging chip comprises two tube cores instead of one tube core, so that the input power capacity of a single packaging chip is improved by two times. And secondly, a 1 * 4 microstrip power divider is connected with the four sub-rectification circuits, so that the radio frequency input power is increased by 4 times (6dB), and the high-power input of 40dBm (10W) is achieved. And the urgent demand of people on high-power wireless charging in nowadays society is finally met.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave energy transmission, and in particular relates to a high-power microwave rectification circuit based on a 1×4 power divider. Background Art

[0002] In recent years, with the continuous development of new energy technologies, people have an increasing demand for cable-free charging and high-power charging. Microwave Wireless Power Transmission (WMPT) technology is one of the research directions of wireless energy transmission. The system performs wireless charging by transmitting microwave energy. As one of the key circuits in the WMPT system, the microwave rectifier circuit can convert the microwave energy received at the antenna end into DC energy to charge the subsequent devices. The performance of the microwave rectifier circuit determines the transmission performance of the entire WMPT system, so the research on the microwave rectifier circuit is crucial. However, with the development of today's society, we can personally feel that people's demand for high-power charging is becoming more and more intense, especially the charging speed of smart phones and new energy vehicles. Large charging power can reduce charging time and bring convenience to people's lives. Therefore, it is necessary to study the high-power performance indicators of the rectifier circuit.

[0003] In the patent [CN117155142A], a GaN Schottky diode is used to design a high-power microwave rectifier circuit. Due to the advanced technology, a 5.8GHz high-power microwave rectifier circuit designed with a GaN diode has a maximum rectification efficiency of 78.9% when the input power is 31dBm, which has very good performance. However, this series of homemade diodes are not widely used commercially and cannot be purchased directly under normal circumstances, so they have no reference value. In the patent [CN110401362A], a GaN field effect transistor CGH40010F is used to design a 1.7GHz high-power microwave rectifier circuit. When the input power is 40dBm, the maximum rectification efficiency is 73.2%, which has good high power and high efficiency performance. However, the rectifier circuit designed with a transistor requires additional power supply at the gate to work properly, which increases the complexity of the rectifier circuit and is insufficient in the actual application of microwave wireless energy transmission.

[0004] In order to overcome the above shortcomings, this paper proposes a high-power microwave rectifier circuit based on a 1×4 power divider. First, this paper selects the Si-based Schottky diode HSMS-270C (BV=25V) with a higher reverse breakdown voltage, and a diode package chip contains two tube cores instead of one tube core, and the input power capacity of a single package chip is increased by 2 times. Secondly, a 1×4 microstrip power divider is used to connect four sub-rectifier circuits, which increases the RF input power by 4 times (6dB) to a high-power input of 40dBm (10 watts). Ultimately, it meets the urgent needs of people in today's society for high-power wireless charging. Summary of the invention

[0005] In order to overcome the problem of insufficient input power in traditional microwave rectifier circuits, the present invention combines the principles of increasing power capacity with large reverse breakdown voltage diodes and increasing power capacity with external power dividers, and proposes a high-power microwave rectifier circuit based on a 1×4 power divider.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A high-power microwave rectifier circuit based on a 1×4 power divider is characterized by comprising a dielectric substrate, a microstrip circuit arranged on the upper surface of the dielectric substrate, and a metal ground arranged on the lower surface of the dielectric substrate. The circuit structure includes a 1×4 power divider, four sub-rectifier circuits, a load resistor, and a metal ground.

[0008] The 1×4 power divider is composed of a metal microstrip line, located on the upper surface of the dielectric substrate, and has an RF input port and four RF output ports. The single RF input port is connected to the externally supplied RF energy, and the four RF output ports are respectively connected to the input ends of the four sub-rectifier circuits to supply energy to each sub-rectifier circuit. The main function of the 1×4 power divider is to expand the power capacity of the entire rectifier circuit, and to expand the small input power of the four sub-rectifier circuits by 4 times to become a rectifier circuit with a large input power, thereby meeting the 40dBm (10 watts) high power input proposed in this patent.

[0009] The four sub-rectifier circuits are four completely identical sub-rectifier circuits. This patent takes a single sub-rectifier circuit as an example, and the other sub-rectifier circuits are analogous. A single sub-rectifier circuit is composed of a metal microstrip line, a lumped capacitor and inductor, and a Schottky diode. Among them, the metal microstrip line is used to connect devices and impedance matching. The metal microstrip lines at the RF input and DC output ends of the sub-rectifier circuit are used to connect various devices, such as RF coaxial connectors, lumped capacitors and inductors; of course, the microstrip lines at both ends of the Schottky diode are not only used to connect diodes, but also for impedance matching of the rectifier circuit. One of the two microstrip lines is a grounded series diode, and the other is an open circuit parallel diode. Among them, the lumped capacitor and inductor include a DC capacitor, a filter capacitor, and a filter inductor. The DC capacitor is placed at the RF input end of the sub-rectifier circuit to block the DC from entering the input end, causing external device damage and DC loss; the filter capacitor and filter inductor are placed at the output end of the sub-rectifier circuit to filter out the RF signal and smooth the DC ripple, which is essentially a low-pass filter. Among them, the HSMS-270C Schottky diode is connected to two sections of metal microstrip lines for impedance matching. The Schottky diode is the core component of the rectifier circuit, which can make the voltage forward conduct and reverse cut off, thereby generating a half-sine wave, which is then filtered and smoothed by the filter at the output end to finally generate the desired DC signal.

[0010] One end of the load resistor is connected to the DC output end of two of the sub-rectifier circuits, and the other end of the resistor is connected to the DC output end of the remaining two sub-rectifier circuits, and its function is to receive the DC output energy of the four sub-rectifiers. The metal ground is used as the zero potential voltage reference ground of the entire rectifier circuit.

[0011] In the present invention,

[0012] 1. The structure of 1×4 power divider plus sub-rectifier circuit is adopted to improve the maximum power capacity of the whole microwave rectifier circuit. The 1×4 power divider increases the small input power of the four sub-rectifier circuits by 4 times, turning it into a rectifier circuit with high input power, thereby meeting the 40dBm (10 watts) high power input proposed by this patent.

[0013] 2. The Schottky diode HSMS-270C with a higher reverse breakdown voltage is used. The diode consists of two tube cores. The reverse breakdown voltage of a single tube core reaches 25V, and the reverse breakdown voltage of two series-connected tube cores can reach 50V, which greatly improves the maximum power capacity of the rectifier circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the high-power rectifier circuit structure.

[0015] Figure 2 This is the circuit schematic of a 1×4 power divider.

[0016] Figure 3 This is the equivalent model diagram of the HSMS-270C Schottky diode.

[0017] Figure 4 This is the simulation result diagram of the high-power rectifier circuit. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0019] A high-power microwave rectifier circuit based on a 1×4 power divider, with an operating center frequency of 2.45 GHz, includes a dielectric substrate, a microstrip circuit arranged on the upper surface of the dielectric substrate, and a metal ground arranged on the lower surface of the dielectric substrate. The size of the entire circuit is 64.7 mm×48.5 mm. The circuit structure includes a 1×4 power divider, 4 sub-rectifier circuits, a load resistor, and a metal ground. The dielectric substrate model is Rogers RO4003C, with a thickness of 0.508 mm, a relative dielectric constant of 3.55, and a loss tangent of 0.0027.

[0020] Figure 1 This is a schematic diagram of the high-power rectifier circuit structure of this patent. The size of the entire circuit is 64.7mm×48.5mm. It includes an RF input source Pin, a 1×4 power divider PD, a load resistor RL=94Ω, and four identical sub-rectifier circuits. Among them, it can be seen that each sub-rectifier circuit contains a DC blocking capacitor Cin=24pF, a filter capacitor Cout=68pF, a filter inductor Lout=56nH, a Schottky diode chip HSMS-270C, and two matching microstrip lines TL1 and TL2. The packages used for the DC blocking capacitor Cin, the filter capacitor Cout, and the filter inductor Lout are all Murata capacitors and inductors in 0402 packages, and the Schottky diode HSMS-270C uses AVAGO's silicon-based diode in SOT-323 packages. The two microstrip lines TL1 and TL2 are used for impedance matching, matching the input impedance of each sub-rectifier to 50Ω to reduce the return loss of the rectifier circuit and increase the rectification conversion efficiency. The length and width of TL1 are 2mm×8mm, and the length and width of TL2 are 9mm×5mm.

[0021] in, Figure 2The structure diagram of the 1×4 power divider is shown in Figure 1. The size of the entire circuit is 60.4mm×19.1mm. The center frequency of the power divider is 2.45GHz, and it is used to connect four sub-rectifier circuits to expand the RF energy at the input end by 4 times. The design process of the 1×4 power divider is as follows: first design a 1×2 power divider, and then connect three 1×2 power dividers to form a 1×4 power divider. The 1×2 power divider is also composed of a 50Ω microstrip line and two λ / 4 microstrip lines, and the 50Ω microstrip line is connected to the input end, the two λ / 4 microstrip lines are connected to the output end, and the 50Ω microstrip line and the λ / 4 microstrip line are connected to each other. Because the characteristic impedance of the microstrip line at the RF input end is 50Ω, and the characteristic impedance of the two parallel λ / 4 microstrip lines is the same, it can be seen from the parallel relationship that the input impedance looking into the λ / 4 microstrip line is 100Ω. According to the λ / 4 transmission line theory, the characteristic impedance of the λ / 4 microstrip line can be obtained as Finally, connect the three completed 1×2 power dividers together to complete the design of a 1×4 power divider.

[0022] in, Figure 3 This is the equivalent model diagram of the HSMS-270C Schottky diode. The equivalent model of the Schottky diode is built in the ADS (Advanced Design System) simulation software according to the data sheet provided on its official website. The reverse breakdown voltage of the diode Bv = 25V, the series parasitic resistance Rs = 0.65Ω, the junction capacitance Cjo = 6.7pF, the saturation current Is = 0.14uA, the ideal factor N = 1.04, the reverse leakage current Ibv = 0.1mA, the capacitance coefficient M = 0.5 and the band gap Eg = 0.55 are all constants, and the capacitance Cp = 0.09pF and the inductance LB = 0.86nH are the equivalent circuits of the chip peripheral package. The larger the reverse breakdown voltage Bv of the diode, the larger the rated power withstand value of the diode. The Bv of the HSMS-270C Schottky diode is 25V, which is much larger than the Bv of the HSMS-2820 Schottky diode is 15V. Moreover, an HSMS-270C diode chip contains two tube cores, which is twice as large as the power capacity of a single-tube diode chip. Therefore, the HSMS-270C has a larger rated power withstand value, and the power capacity of the rectifier circuit will also be larger.

[0023] in, Figure 4 The following is a simulation result of the rectification efficiency of the high-power rectifier circuit. The high-power microwave rectifier circuit of the 1×4 power divider of this patent is simulated and designed in the ADS software. From the simulation curve, it can be seen that when the input power is 40dBm, the rectification efficiency is 66%, and the corresponding DC load output voltage is 25V. It has a relatively good high-power performance and a higher DC output voltage.

[0024] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high-power microwave rectifier circuit based on a 1×4 power divider, characterized in that: It includes a dielectric substrate, a microstrip circuit arranged on the upper surface of the dielectric substrate, and a metal ground arranged on the lower surface of the dielectric substrate. The circuit structure includes a 1×4 power divider, 4 sub-rectifier circuits, a load resistor, and a metal ground; The main function of the 1×4 power divider is to expand the power capacity of the entire rectifier circuit, and to expand the small input power of the four sub-rectifier circuits by four times to become a rectifier circuit with a large input power; The four sub-rectifier circuits are four completely identical sub-rectifier circuits, and each sub-rectifier circuit is used to convert radio frequency energy into direct current energy; wherein, the HSMS-270C Schottky diode in the sub-rectifier circuit can make the voltage forward conduction and reverse cutoff, thereby generating a half-sine wave, which is then filtered and smoothed by the filter at the output end, and finally generates the desired direct current signal. The load resistor is used to receive the DC output energy of the four sub-rectifiers. The metal ground is used as a zero potential voltage reference ground for the entire rectifier circuit.

2. A high efficiency rectifier circuit and design method according to claim 1, characterized in that: The 1×4 power divider includes: a 1×4 power divider PD. The 1×4 power divider is composed of a metal microstrip line, located on the upper surface of a dielectric substrate, and has an RF input port and four RF output ports. The single RF input port is connected to externally supplied RF energy, and the four RF output ports are respectively connected to the input ends of four sub-rectifier circuits to supply energy to each sub-rectifier circuit.

3. A high efficiency rectifier circuit and design method according to claim 1, characterized in that: The four sub-rectifier circuits include: metal microstrip lines, lumped capacitors and inductors, and Schottky diodes; The metal microstrip line is used to connect devices and for impedance matching, such as for connecting RF coaxial connectors and lumped capacitors and inductors. The microstrip lines at both ends of the Schottky diode are not only used to connect the diodes, but also for impedance matching of the rectifier circuit. One of the two microstrip lines is a grounded series diode, and the other is an open circuit parallel diode. The lumped capacitor and inductor include a DC-stack capacitor, a filter capacitor, and a filter inductor, wherein the DC-stack capacitor is placed at the radio frequency input end of the sub-rectifier circuit, and the filter capacitor and the filter inductor are placed at the output end of the sub-rectifier circuit. The Schottky diode is connected to two sections of metal microstrip lines for impedance matching.

4. A high efficiency rectifier circuit and design method according to claim 1, characterized in that: The load resistor and the metal floor include: a load resistor RL and a metal floor; One end of the load resistor is connected to the DC output ends of two of the sub-rectifier circuits, and the other end of the resistor is connected to the DC output ends of the remaining two sub-rectifier circuits; the metal floor is placed on the lower surface of the entire dielectric substrate.

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