Wide-load radio frequency rectification circuit

Abstract

The wide-load radio frequency rectification circuit comprises an impedance matching network, a dynamic compensation network, a first rectification diode and a straight-through filter, the output end of the impedance matching network is connected with one end of the straight-through filter and one end of the first rectifier diode, the other end of the first rectifier diode is connected with the dynamic compensation network, and the output end of the straight-through filter is connected with a load; the quarter-wavelength microstrip line is connected with one end of the first wavelength-adjustable microstrip line and one end of the second wavelength-adjustable microstrip line, the other end of the second wavelength-adjustable microstrip line is connected with one end of the second rectifier diode, and the other end of the second rectifier diode is grounded. In the dynamic compensation network, a quarter-wavelength microstrip line, a first wavelength-adjustable microstrip line and a second wavelength-adjustable microstrip line form a T-shaped network to change the impedance of a second rectifier diode so as to compensate an imaginary part of a first rectifier diode, thereby suppressing impedance fluctuation caused by load change.

Description

Technical Field

[0001] The present application relates to the technical field of radio frequency circuits, and in particular to a wide load radio frequency rectifier circuit. Background Art

[0002] As more and more sensors are used in IoT applications, the power demand for these sensors is also growing. The rectifier circuit is a key component of the RF energy harvesting system. However, the energy conversion efficiency of the rectifier is affected by the load impedance.

[0003] In the related art, 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, how to make the rectifier meet a wide load range to adapt to different scenarios or dynamic loads is an urgent problem to be solved. Summary of the invention

[0004] In view of the above problems, the present application provides a wide load radio frequency rectifier circuit to at least solve the problems existing 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 comprising:

[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 respectively connected to the pass 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 pass filter is connected to a load;

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

[0008] In some embodiments, 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.

[0009] In some embodiments, a first capacitor is further provided between the third tunable wavelength microstrip line and the microwave source, and 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.

[0010] In some embodiments, the pass 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.

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

[0012] In some embodiments, 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.

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

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

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

[0016] A wide load radio frequency rectification circuit provided in an embodiment of the present application includes: an impedance matching network, a dynamic compensation network, a first rectification diode and a pass filter; the output end of the impedance matching network is respectively connected to one end of the pass filter and the first rectification diode, the other end of the first rectification diode is connected to the dynamic compensation network, and the output end of the pass filter is connected to a load; wherein the dynamic compensation network includes a quarter-wavelength microstrip line, a first adjustable wavelength microstrip line, a second adjustable wavelength microstrip line and a second rectification diode; the quarter-wavelength microstrip line is respectively connected to one end of the first adjustable wavelength microstrip line and 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, a T-type network is formed in the dynamic compensation network to convert the capacitive impedance of the second rectification diode into an inductive impedance, which can compensate for the capacitive impedance of the first rectification diode, thereby suppressing impedance fluctuations caused by load changes.

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

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

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

[0020] Figure 2A schematic diagram of impedance matching results under different input powers proposed in the embodiments of the present application is shown;

[0021] Figure 3 A schematic diagram showing measurement and simulation results of a rectifier designed using a HSMS282C diode proposed in an embodiment of the present application is shown;

[0022] Figure 4 A schematic diagram of measurement and simulation results of a rectifier designed using the HSMS2860 diode proposed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0024] As more and more sensors are used in IoT applications, the power demand for these sensors is also growing. The rectifier circuit is a key component of the RF energy harvesting system. However, the energy conversion efficiency of the rectifier is affected by the load impedance.

[0025] In the study of related technologies, it is found that 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 rectifier with a wide load range is required to adapt to different scenarios or dynamic loads.

[0026] In response to the above-mentioned problem description, the applicant proposed a wide-load RF rectifier circuit provided by an embodiment of the present application, including: 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 respectively connected to one end of the pass-through filter and 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 pass-through filter is connected to a load; wherein the dynamic compensation network includes a quarter-wavelength microstrip line, a first adjustable wavelength microstrip line, a second adjustable wavelength microstrip line and a second rectifier diode; the quarter-wavelength microstrip line is respectively connected to one end of the first adjustable wavelength microstrip line and the second adjustable wavelength microstrip line, 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, and the capacitive impedance of the second rectifier diode is converted into an inductive impedance through a T-type network formed in the dynamic compensation network, so that the capacitive impedance of the first rectifier diode can be compensated, thereby suppressing impedance fluctuations, so that the rectifier meets a wide load range to adapt to different scenarios or dynamic loads.

[0027] The wide load RF rectifier circuit provided in the embodiment of the present application is introduced below:

[0028] See also Figure 1 , Figure 1 Schematic diagram of a wide load RF rectifier circuit structure provided in an embodiment of the present application. In the figure, the wide load RF 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 respectively connected to the pass filter and one end of the first rectifier diode D1, the other end of the first rectifier diode D1 is connected to the dynamic compensation network, and the output end of the pass filter is connected to the 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 respectively connected to the first adjustable wavelength microstrip line TL4 and one end of the second adjustable wavelength microstrip line TL3, the other end of the second adjustable wavelength microstrip line TL3 is connected to one end of the second rectifier diode D2, and the other end of the second rectifier diode D2 is grounded. The T-type 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 an inductive impedance, which can compensate for the capacitive impedance of the first rectifier diode D1, thereby suppressing impedance fluctuations, so that the rectifier meets a wide load range to 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 resistance of the rectifier to avoid the diode being broken down 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 tunable wavelength microstrip line TL1 , and an input end of the third tunable wavelength microstrip line TL1 is connected to a microwave source MW to reduce reflection of radio frequency energy and improve conversion efficiency of radio frequency energy.

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

[0032] Preferably, the first capacitor C1 is a DC blocking capacitor.

[0033] In some embodiments, the straight-through filter includes: a microstrip line TL2 and a second capacitor C2, wherein one end of the second capacitor C2 is connected to the microstrip line TL2, and the other end is grounded.

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

[0035] In some embodiments, the microwave source MW is connected to an active terminal impedance Z s , source impedance Z s One end is connected to 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 this embodiment, Figure 1 The direct-pass filter consists of a quarter-wavelength microstrip line TL2 and a parallel capacitor, with an input impedance of Z in3 It is infinite for the RF fundamental signal, so it will not have a significant impact on the matching.

[0038] In this application, the load R can be connected through a multimeter L To measure the load R L of DC voltage.

[0039] The T-type network consists of TL3, TL4 and TL5, where the length of TL3 satisfies:

[0040] l3≈λ g / 4;

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

[0042] The impedance of the second rectifier diode D2 is set to R d2 -jX d2 , R d2 and X d2 For load R L Function, using the impedance formula of the transmission line, we can get the input impedance Z in8 The admittance formula of .

[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] Using the impedance formula for a quarter impedance transformer and an open transmission line, we get:

[0046]

[0047] The impedance of the first rectifier diode D1 is set to R d1 -jXd1 For load R L The function of R d1 and X d1 Where 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, θ4=βl4.

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

[0049]

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

[0051] The load range can be adjusted to satisfy the above expression by adjusting the lengths 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 and imaginary parts of Zin4 can remain stable within a wide load range.

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

[0053] Z in4 ≈A+jB;

[0054] Among them, A and B are constants.

[0055] Z in 2 can be expressed as:

[0056]

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

[0058] The expression of input impedance Zin1 is:

[0059]

[0060] Where Z1 and 1 are the selected values ​​of the Smith chart tool, and A and B are constants.

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

[0062] In the simulation of the wide load RF rectifier circuit in the application process, it is necessary to obtain the simulation file model of the rectifier diode, and then use the above formula to preliminarily design the characteristic impedance Z3, Z4, Z5 and length l3, l4, l5 of TL3, TL4 and TL5. Then, according to the resistance value of Zin2, a preliminary impedance matching design is performed to obtain the values ​​of Z1 and l1. Finally, the overall circuit parameters are simulated and optimized with the help of simulation software to improve the performance of the circuit.

[0063] In the simulation process, the wide load RF rectifier circuit optimizes the T-type network (composed of TL3, TL4 and TL5) to keep the real and imaginary parts of Zin4 relatively stable in the widest load range possible to achieve impedance matching in a wide dynamic range. The value of Zin4 needs to be obtained in Zin1 and Zin9 to determine the length and width of TL1. During the simulation process, the ultimate goal is to make Zin1 reach 50Ω in a wide load range to achieve a good impedance effect.

[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 A schematic diagram of 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 the HSMS282C diode 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 A schematic diagram of measurement and simulation results of a rectifier designed using the HSMS2860 diode provided in an embodiment of the present application.

[0071] Figure 4In the design, when the input power is 3dBm, the rectification efficiency of the designed rectifier exceeds 50% in the load range of 2.5kΩ to 32.5kΩ.

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

[0073] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from 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 filter; the output end of the impedance matching network is respectively connected to the pass 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 pass 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 respectively connected to one end of the first tunable wavelength microstrip line and the second tunable wavelength microstrip line, 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 radio frequency rectifier circuit according to claim 1, characterized in that: The impedance matching network comprises: a third tunable wavelength microstrip line, and an input end of the third tunable wavelength microstrip line is connected to a microwave source.

3. According to the wide load RF rectifier circuit of claim 2, 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 to the third adjustable 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 comprises 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 rectifying diode and the second rectifying diode include HSMS282C diodes.

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

9. The wide load radio frequency rectifier circuit according to claim 5, characterized in that: The resistance value of the source end impedance is 50 ohms.

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