CN-121984466-A - Tunable high-temperature superconducting limiter based on voltage regulation

CN121984466ACN 121984466 ACN121984466 ACN 121984466ACN-121984466-A

Abstract

The invention relates to the technical field of anti-interference receiving and discloses a voltage-regulation-based tunable high-temperature superconducting amplitude limiter, which comprises a radio frequency signal input end P1, a first impedance transformation section component, a superconducting amplitude limiting section L4, a direct-current bias regulation circuit for introducing bias current into the superconducting amplitude limiting section L4, a second impedance transformation section component and a radio frequency signal output end P2, wherein the first impedance transformation section component and the second impedance transformation section component have the same structure and comprise a section of superconducting microstrip transmission line, a series-arranged direct-current blocking capacitor and an impedance transformation section. The invention can change the working current density of the high-temperature superconductive amplitude limiting section in the range close to or far from the critical current density of the superconductive material by adjusting the magnitude of the bias current on the premise of not changing the geometric parameters of the high-temperature superconductive amplitude limiting section, thereby realizing the tuning of the amplitude limiting threshold and the power bearing capacity of the amplitude limiter.

Inventors

Ying Huanghao
ZHANG HUIYU
ZHANG XIAOLE
Cheng Huafei
LI XIANG
LIAO RUOCHEN
ZHANG ZHONGHAI

Assignees

杭州电子科技大学

Dates

Publication Date: 20260505
Application Date: 20260121

Claims (9)

1. The tunable high-temperature superconducting limiter based on voltage regulation is characterized by comprising a radio frequency signal input end P1, a first impedance transformation node assembly, a superconducting limiting node L4, a direct-current bias regulation circuit for introducing bias current into the superconducting limiting node L4, a second impedance transformation node assembly and a radio frequency signal output end P2 which are electrically connected in sequence, so that impedance matching of the device in a normal working state is ensured; The first impedance transformation node assembly and the second impedance transformation node assembly have the same structure and comprise a section of superconducting microstrip transmission line, a DC blocking capacitor and an impedance transformation node, wherein the DC blocking capacitor and the impedance transformation node are arranged in series and are used for realizing impedance transition in a radio frequency working frequency band and blocking leakage of DC signals to the direction of a port.
2. The voltage-regulation-based tunable high-temperature superconducting limiter according to claim 1, wherein the superconducting microstrip transmission line is a microwave input end, and the direct-current blocking capacitor is a variable reactance.
3. The voltage regulation-based tunable high temperature superconducting limiter of claim 2, wherein the first impedance transformation section assembly comprises a microwave input terminal L1, an input terminal variable reactance C1 and an input impedance transformation section L3 electrically connected in sequence; The second impedance transformation node assembly comprises an output impedance transformation node L5, an output end variable reactance C2 and a microwave output end L2 which are electrically connected in sequence; The input end variable reactance C1 and the output end variable reactance C2 are used for blocking direct current signals and finely adjusting current density values on the superconducting limiting section L4, and only microwave signals are allowed to pass through.
4. The voltage-regulation-based tunable high-temperature superconducting limiter of claim 3 wherein the superconducting limiter section L4 is located intermediate the input impedance transformation section L3 and the output impedance transformation section L5, the superconducting limiter section L4 being a region of high-temperature superconducting conductor narrowed with respect to the transmission line widths on both sides thereof, extending in the microwave signal transmission direction, and being integrally formed with the input impedance transformation section L3 and the output impedance transformation section L5.
5. The voltage-adjustment-based tunable high-temperature superconductor amplitude limiter of claim 4, wherein the superconductor amplitude limiter L4 is formed by a section of high-temperature superconductor microstrip transmission line with a fixed geometric dimension, and the width and length of the superconductor amplitude limiter are determined in the design and preparation stages of the device, so that a high-current density region is formed under the action of high-power microwave signals.
6. The voltage-adjustment-based tunable high-temperature superconducting limiter of claim 1, wherein the voltage-adjustment-based tunable high-temperature superconducting limiter is arranged on the surface of a dielectric substrate and is formed by processing a high-temperature superconducting film.
7. The voltage-regulation based tunable high-temperature superconducting limiter of claim 4 wherein the superconducting limiter L4 has a width of 50 ohm microstrip.
8. The voltage-regulation-based tunable high-temperature superconductor limiter of any one of claims 1 to 5, wherein the DC bias regulation circuit comprises a DC power supply Vcc, a radio-frequency isolation signal large inductor L1, a radio-frequency isolation signal large inductor L2, a voltage dividing resistor R and a grounding end GND, one end of the superconductor limiter L4 is connected with the DC power supply Vcc through the radio-frequency isolation signal large inductor L1, the other end of the superconductor limiter L4 is connected with the grounding end GND sequentially through the radio-frequency isolation signal large inductor L2 and the voltage dividing resistor R, and the DC bias regulation circuit is used for introducing an adjustable bias current into the superconductor limiter L4 so as to regulate the current density in the superconductor limiter L4.
9. The voltage-regulating-based tunable high-temperature superconducting limiter of claim 8, wherein the divider resistor R is 3-10Ω.

Description

Tunable high-temperature superconducting limiter based on voltage regulation Technical Field The invention relates to the technical field of anti-interference receiving, in particular to a tunable high-temperature superconductive amplitude limiter based on voltage regulation. Background Since the discovery of high temperature superconductors (High Temperature Superconductor, HTS) in 1986, devices based on HTS materials have been widely and intensively studied in the fields of mobile communication systems, satellite communications, radio astronomy, and radar. The superconductor has a meissner effect, i.e. when the current density on the superconducting transmission line is below the critical current density value of the superconductor, the superconducting transmission line is in a superconducting state of very low resistance, and when the current density on the superconducting transmission line exceeds the critical current density value of the superconductor, the superconducting transmission line loses superconductivity and is converted into a high-resistance state. HTS limiters based on the superconducting meissner effect also have very low insertion loss due to the very low sheet resistance of the HTS film. The limiter can greatly reduce the influence on the sensitivity of a receiver system on the premise of realizing effective protection of a receiving circuit, thereby having important application value in a high-performance radio frequency front end. By utilizing the characteristic that the superconducting material has critical current density (Jc), when the input power received by the device is gradually increased, the current flowing on the superconducting film is also continuously increased, and along with the increase of the current density on the superconducting film, until the critical current density of the superconducting film is reached, the high-temperature superconducting film is quenched, the device loses zero resistance, the loss is increased, and the limiter starts to play a role. For high temperature superconductive microwave limiter, there are two main schemes, one of which is realized by adding microbridge structure (high temperature superconductive limiter) to uniform microstrip transmission line, its typical structure is shown in figure 1, and the other is realized by coplanar waveguide structure with micro-scale 50The transmission line is used for clipping purposes, and its typical structure is shown in fig. 2. However, the two limiter structures realize the limitation of the microwave signal through the microstrip width of the limiter section, and the limitation characteristic of the limiter structure is closely related to the width and length parameters of the superconductive limiter section. When the width and length of the high temperature superconductive limiter are determined in the design and preparation stages, the corresponding critical current density and power carrying capacity are fixed, for example, the critical current density of the YBCO superconductive film material at 77K is 10 6A/cm2-107A/cm2, so that the power capacity of the device cannot be adjusted after the structure is formed. Therefore, after the design of the high-temperature superconductive microwave limiter in the prior art is finished, the limiting threshold and the maximum bearable input power of the high-temperature superconductive microwave limiter are difficult to flexibly adjust according to different application scenes, and when the actual input power is not matched with the design power, the problem that the limiting effect is insufficient or the high-temperature superconductive microwave limiter enters a quench state too early easily occurs, so that the application range and the engineering application flexibility of the superconductive limiter are limited. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a voltage-adjustment-based tunable high-temperature superconductive amplitude limiter, which can enable an amplitude limiting threshold to be continuously adjustable within a small range near critical current density on the premise of not changing geometric parameters of a high-temperature superconductive amplitude limiting section, adapt to different input power levels and application scenes, and improve the reliability and application range of the device. According to the voltage-adjustment-based tunable high-temperature superconducting limiter, the direct-current bias is introduced into the limiter to roughly adjust the current density on the superconducting transmission line, and then the variable reactance values at two ends of the limiting circuit are adjusted to finely adjust the current density on the superconducting transmission line, so that the current density in the high-temperature superconducting limiting section is precisely adjusted by superposition of the current densities generated by the two schemes. The scheme can enable t