A wide load radio frequency rectifier circuit

Abstract

The application discloses a wide-load radio frequency rectifier circuit, which comprises an impedance matching network, a dynamic compensation network, a first rectifier diode and a pass filter; the output end of the impedance matching network is connected with one end of the pass filter and the first rectifier diode respectively, the other end of the first rectifier diode is connected with the dynamic compensation network, and the output end of the pass filter is connected with a load; a quarter-wavelength microstrip line is connected with one end of a first adjustable wavelength microstrip line and one end of a second adjustable wavelength microstrip line, the other end of the second adjustable wavelength microstrip line is connected with one end of a second rectifier diode, the other end of the second rectifier diode is grounded, and the quarter-wavelength microstrip line, the first adjustable wavelength microstrip line and the second adjustable wavelength microstrip line in the dynamic compensation network form a T-shaped network to change the impedance of the second rectifier diode, so that the imaginary part of the first rectifier diode is compensated, and the impedance fluctuation caused by the load change is inhibited.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radio frequency circuit, and particularly relates to a wide load radio frequency rectifier circuit. BACKGROUND

[0002] With more and more sensors being used in Internet of Things applications, the power supply requirements for these sensors are also growing, and the rectifier circuit is a key component of a radio frequency energy harvesting system, however, the energy conversion efficiency of the rectifier will be affected by the load impedance.

[0003] In the related art, the current rectifier usually has poor rectification efficiency under low resistance or high resistance load, and is not suitable for wide load rectification. In addition, the impedance of some loads is not fixed, such as motors, batteries, light emitting diodes and other active devices. Therefore, how to make the rectifier meet the wide load range to adapt to different scenarios or dynamic loads is an urgent problem to be solved. SUMMARY

[0004] In view of the above problems, the present application provides a wide load radio frequency rectifier circuit to at least solve the problems in the related art.

[0005] The embodiment of the present application provides a wide load radio frequency rectifier circuit, the wide load radio frequency rectifier circuit comprises:

[0006] An impedance matching network, a dynamic compensation network, a first rectifier diode and a pass filter; the output end of the impedance matching network is connected with one end of the pass filter and the first rectifier diode respectively, the other end of the first rectifier diode is connected with the dynamic compensation network, and the output end of the pass filter is connected with a load;

[0007] The dynamic compensation network comprises a quarter wavelength microstrip line, a first adjustable wavelength microstrip line, a second adjustable wavelength microstrip line and a second rectifier diode; one end of the quarter wavelength microstrip line is connected with the first adjustable wavelength microstrip line and the second adjustable wavelength microstrip line respectively, the other end of the second adjustable wavelength microstrip line is connected with one end of the second rectifier diode, and the other end of the second rectifier diode is grounded.

[0008] In some embodiments, the impedance matching network comprises a third adjustable wavelength microstrip line, and an input end of the third adjustable wavelength microstrip line is connected with a microwave source.

[0009] In some embodiments, a first capacitor is further arranged between the third adjustable wavelength microstrip line and the microwave source, one end of the first capacitor is connected with the third adjustable wavelength microstrip line, and the other end of the first capacitor is connected with the microwave source.

[0010] In some embodiments, the through filter comprises a microstrip line and a second capacitor, one end of the second capacitor being connected to the microstrip line and the other end being grounded.

[0011] In some embodiments, the microstrip line is a quarter wavelength microstrip line.

[0012] In some embodiments, the microwave source is connected with a source end impedance, one end of the source end impedance being connected to the microwave source and the other end being grounded.

[0013] In some embodiments, the first rectifier diode and the second rectifier diode comprise HSMS282C diodes.

[0014] In some embodiments, the first rectifier diode and the second rectifier diode comprise HSMS2860 diodes.

[0015] In some embodiments, the source end impedance has a resistance value of 50 ohms.

[0016] The wide load radio frequency rectification circuit provided by the embodiments of the present application comprises an impedance matching network, a dynamic compensation network, a first rectifier diode and a through filter; the output ends of the impedance matching network are respectively connected to one end of the through filter and one end of the first rectifier diode, the other end of the first rectifier diode is connected to the dynamic compensation network, and the output end of the through filter is connected to a load; wherein the dynamic compensation network comprises a quarter wavelength microstrip line, a first adjustable wavelength microstrip line, a second adjustable wavelength microstrip line and a second rectifier diode; one end of the quarter wavelength microstrip line is respectively connected to one end of the first adjustable wavelength microstrip line and one end of the second adjustable wavelength microstrip line, the other end of the second adjustable wavelength microstrip line is connected to one end of the diode, and the other end of the diode is grounded; in the present application, the T-shaped network formed by the dynamic compensation network converts the capacitive impedance of the second rectifier diode into inductive impedance, can compensate the capacitive impedance of the first rectifier diode, and thus suppresses the impedance fluctuation caused by the load change.

[0017] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0018] The present application will be described in more detail below based on embodiments and with reference to the accompanying drawings.

[0019] Figure 1 A structure schematic diagram of a wide load radio frequency rectification circuit proposed in an embodiment of the present application is shown;

[0020] Figure 2Impedance matching results under different input powers are shown.

[0021] Figure 3 Measurement and simulation results of the rectifier designed by using the HSMS282C diode are shown.

[0022] Figure 4 Measurement and simulation results of the rectifier designed by using the HSMS2860 diode are shown. DETAILED DESCRIPTION

[0023] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with embodiments and drawings, and the schematic embodiments of the present application and the description thereof are only used to explain the present application, and not as a limitation to the present application.

[0024] With more and more sensors being used in Internet of Things applications, the power supply requirements for these sensors are also growing. Rectifier circuits are key components of radio frequency energy harvesting systems. However, the energy conversion efficiency of the rectifier is affected by the load impedance.

[0025] In the research of related technologies, it is found that the current rectifiers usually have poor rectification efficiency under low resistance or high resistance loads, and are not suitable for wide load rectification. In addition, the impedance of some loads is not fixed, such as motors, batteries, light emitting diodes and other active devices. Therefore, a wide load range rectifier is needed to adapt to different scenarios or dynamic loads.

[0026] In view of the above problem, the applicant proposes a wide load radio frequency rectifier circuit provided in the embodiments of the present application, which comprises an impedance matching network, a dynamic compensation network, a first rectifier diode and a pass filter. The output end of the impedance matching network is connected to one end of the pass filter and the first rectifier diode, respectively, and the other end of the first rectifier diode is connected to the dynamic compensation network. The output end of the pass filter is connected to a load. The dynamic compensation network comprises a quarter wavelength microstrip line, a first adjustable wavelength microstrip line, a second adjustable wavelength microstrip line and a second rectifier diode. One end of the quarter wavelength microstrip line is connected to the first adjustable wavelength microstrip line and the second adjustable wavelength microstrip line, respectively. The other end of the second adjustable wavelength microstrip line is connected to one end of the second rectifier diode, and the other end of the second rectifier diode is grounded. The capacitive impedance of the second rectifier diode is converted to inductive impedance through the T-shaped network formed in the dynamic compensation network, which can compensate the capacitive impedance of the first rectifier diode, thereby suppressing the impedance fluctuation, so that the rectifier meets the wide load range to adapt to different scenarios or dynamic loads.

[0027] The wide-load radio frequency rectifier circuit provided in the embodiment of the present application is described below.

[0028] Please refer to Figure 1 , Figure 1 The wide-load radio frequency rectifier circuit structure provided in the embodiment of the present application is shown in the figure. The wide-load radio frequency rectifier circuit includes an impedance matching network, a dynamic compensation network, a first rectifier diode, and a pass filter. The output end of the impedance matching network is connected to the pass filter and one end of the first rectifier diode D1, respectively. The other end of the first rectifier diode D1 is connected to the dynamic compensation network. The output end of the pass filter is connected to a load R L The dynamic compensation network includes a quarter-wavelength microstrip line TL5, a first adjustable-wavelength microstrip line TL4, a second adjustable-wavelength microstrip line TL3, and a second rectifier diode D2. The quarter-wavelength microstrip line TL5 is connected to the first adjustable-wavelength microstrip line TL4 and one end of the second adjustable-wavelength microstrip line TL3, respectively. The other end of the second adjustable-wavelength microstrip line TL3 is connected to one end of the second rectifier diode D2. The other end of the second rectifier diode D2 is grounded. The T-shaped network composed of the quarter-wavelength microstrip line TL5, the first adjustable-wavelength microstrip line TL4, and the second adjustable-wavelength microstrip line TL3 in the dynamic compensation network converts the capacitive impedance of the second rectifier diode D2 into inductive impedance, which can compensate for the capacitive impedance of the first rectifier diode D1, thereby suppressing impedance fluctuations to make the rectifier meet the wide-load range and adapt to different scenarios or dynamic loads. In addition, the cascade connection of the second rectifier diode D2 and the first rectifier diode D1 can improve the voltage withstand capability of the rectifier to avoid diode breakdown under high voltage.

[0029] In order to improve the conversion efficiency of radio frequency energy.

[0030] In some embodiments, the impedance matching network includes a third adjustable-wavelength microstrip line TL1. The input end of the third adjustable-wavelength microstrip line TL1 is connected to a microwave source MW to reduce the reflection of radio frequency energy and improve the conversion efficiency of radio frequency energy.

[0031] In some embodiments, a first capacitor C1 is further arranged between the third adjustable-wavelength microstrip line TL1 and the microwave source MW. One end of the first capacitor C1 is connected to the third adjustable-wavelength microstrip line TL1, and the other end is connected to the microwave source MW.

[0032] Preferably, the first capacitor C1 is a direct-current isolation capacitor.

[0033] In some embodiments, the pass filter includes a microstrip line TL2 and a second capacitor C2. One end of the second capacitor C2 is connected to the microstrip line TL2, and the other end is grounded.

[0034] In the embodiment, the pass filter has a strong inhibitory effect on the radio frequency signal, only allowing direct current to pass, so that the radio frequency energy can all enter the rectification branch, thereby improving the conversion efficiency of the radio frequency energy.

[0035] In some embodiments, the microwave source MW is connected with a source impedance Z s , the source impedance Z s is connected with one end of the microwave source MW, and the other end is grounded.

[0036] In some embodiments, the microstrip line TL2 is a quarter-wavelength microstrip line.

[0037] In the embodiment, the pass filter is composed of a quarter-wavelength microstrip line TL2 and a parallel capacitor in Figure 1 , and the input impedance Z in3 is infinite for the radio frequency fundamental signal, so it will not have a great impact on matching.

[0038] In the application, the DC voltage of the load R L can be measured by connecting the load R L with a multimeter.

[0039] The T-network is composed of TL3, TL4 and TL5, wherein the length of TL3 satisfies:

[0040] l3≈λ g / 4;

[0041] In the formula, λ g is the wavelength of the waveguide.

[0042] The impedance of the second rectifier diode D2 is set as R d2 -jX d2 , R d2 and X d2 are functions of the load R L , and the admittance formula of the input impedance Z in8 can be obtained by using the impedance formula of the transmission line.

[0043]

[0044] In the formula, θ5=βl5, a is the real part of Yin8, b is the imaginary part of Yin8, j is the imaginary unit, and β is the phase constant.

[0045] By using the impedance formula of the quarter impedance transformer and the open-circuit transmission line, the following formula can be obtained:

[0046]

[0047] In the formula, the impedance of the first rectifier diode D1 is set as R d1 -jXd1 is a function of the load R L , R d1 and X d1 , a is the real part, b is the imaginary part, j is the imaginary unit, Z3 is the characteristic impedance of the transmission line TL3, Z4 is the characteristic impedance of the transmission line TL4, and θ4 = βl4.

[0048] It can be seen that the open-circuit transmission TL4 can be used to compensate for the imaginary part of the diode D1, so as to reduce the impedance value of Zin4, thereby facilitating the design of impedance matching. In order to make the real part and the imaginary part of Zin4 can be well compensated, the following conditions are met in the widest possible load range:

[0049]

[0050] wherein R L is the load, a is the real part, and b is the imaginary part.

[0051] The load range can meet the above expression by adjusting the length of Z5 and l5 (l5 is the length of the microstrip line, and Z5 is the characteristic impedance of the transmission line TL5), so that the real part and the imaginary part of Zin4 can remain stable in a wide load range.

[0052] The above operation can be completed by using the tuning function of the simulation software. Thus, the following expression can be obtained

[0053] Z in4 ≈ A + jB;

[0054] wherein A and B are constants.

[0055] Z in 2 can be expressed as:

[0056]

[0057] Therefore, only one transmission line is needed to achieve impedance matching, thereby simplifying the design of the impedance matching circuit.

[0058] The expression of the input impedance Zin1 is:

[0059]

[0060] wherein Z1, l1 are the selected values of the Smith chart tool, and A, B are constants.

[0061] The values of Z1 and l1 can be reasonably selected by using the Smith chart tool to obtain a good impedance matching effect.

[0062] When simulating a wide-load RF rectifier circuit, you need to obtain a simulation file model of the rectifier diodes. Using the above formulas, you can preliminarily design the characteristic impedances Z3, Z4, and Z5, as well as the lengths l3, l4, and l5, for TL3, TL4, and TL5. Then, based on the resistance value of Zin2, perform a preliminary impedance matching design to determine the values ​​of Z1 and l1. Finally, use simulation software to optimize the overall circuit parameters to improve circuit performance.

[0063] During simulation, the wide-load RF rectifier circuit optimizes the T-network (composed of TL3, TL4, and TL5) to maintain relatively stable real and imaginary components of Zin4 over the widest possible load range, achieving impedance matching over a wide dynamic range. The value of Zin4 is required in Zin1 and Zin9 to determine the length and width of TL1. The ultimate goal during simulation is to achieve a Zin1 impedance of 50Ω over a wide load range, ensuring optimal impedance matching.

[0064] In some embodiments, the first rectifier diode and the second rectifier diode are experimentally tested using HSMS282C diodes.

[0065] In some embodiments, the first rectifier diode and the second rectifier diode are experimentally tested using HSMS2860 diodes.

[0066] See also Figure 2 , Figure 2 This is a schematic diagram of the impedance matching results under different input powers provided in an embodiment of the present application.

[0067] exist Figure 2 In the figure, the input matching simulation results of the wide load rectifier designed using the HSMS282C diode are shown, and the results show good matching over a wide load range.

[0068] See also Figure 3 , Figure 3 Schematic diagram of measurement and simulation results of a rectifier designed using HSMS282C diodes provided in an embodiment of the present application.

[0069] Figure 3 In the case of an input power of 15dBm, the rectification efficiency exceeds 50% in the load range of 0.25kΩ to 9.5kΩ.

[0070] See also Figure 4 , Figure 4 Schematic diagram of measurement and simulation results of a rectifier designed using HSMS2860 diodes provided in an embodiment of the present application.

[0071] Figure 4When the input power is 3 dBm, the rectifier designed in this paper has a rectification efficiency of more than 50% in the load range of 2.5 kΩ to 32.5 kΩ.

[0072] The measurement results show that the proposed wide-load RF rectifier circuit can not only widen the load range of the rectifier, but also be applicable to different diode models.

[0073] The above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not drive the essence of the corresponding technical solutions out of the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A wide load radio frequency rectifier circuit, characterized in that: include: An impedance matching network, a dynamic compensation network, a first rectifier diode, and a pass-through filter; the output end of the impedance matching network is connected to the pass-through filter and one end of the first rectifier diode, respectively, the other end of the first rectifier diode is connected to the dynamic compensation network, and the output end of the pass-through filter is connected to a load; Wherein, the dynamic compensation network includes a quarter-wavelength microstrip line, a first tunable wavelength microstrip line, a second tunable wavelength microstrip line and a second rectifier diode; The quarter-wavelength microstrip line is connected to one end of the first tunable wavelength microstrip line and one end of the second tunable wavelength microstrip line respectively, the other end of the second tunable wavelength microstrip line is connected to one end of the second rectifier diode, and the other end of the second rectifier diode is grounded.

2. The wide load RF rectifier circuit according to claim 1, characterized in that: The impedance matching network includes: a third tunable wavelength microstrip line, and an input end of the third tunable wavelength microstrip line is connected to a microwave source.

3. The wide-load RF rectifier circuit according to claim 2, wherein a first capacitor is further provided between the third tunable wavelength microstrip line and the microwave source, wherein one end of the first capacitor is connected to the third tunable wavelength microstrip line, and the other end is connected to the microwave source.

4. The wide load radio frequency rectifier circuit according to claim 1, characterized in that: The straight-through filter includes a microstrip line and a second capacitor, wherein one end of the second capacitor is connected to the microstrip line and the other end is grounded.

5. The wide load radio frequency rectifier circuit according to claim 4, characterized in that: The microstrip line is a quarter-wavelength microstrip line.

6. The wide load radio frequency rectifier circuit according to claim 2, characterized in that: The microwave source is connected to a source end impedance, one end of the source end impedance is connected to the microwave source, and the other end is grounded.

7. The wide load radio frequency rectifier circuit according to claim 1, characterized in that: The first rectifier diode and the second rectifier diode include HSMS282C diodes.

8. The wide load radio frequency rectifier circuit according to claim 1, characterized in that: The first rectifier diode and the second rectifier diode include HSMS2860 diodes.

9. The wide load radio frequency rectifier circuit according to claim 6, characterized in that: The resistance value of the source end impedance is 50 ohms.

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