Дослідження резонансних властивостей пристроїв перемикання на основі високотемпературного надпровідника

Abstract

The results of experimental studies showed that in a hightemperature superconductor under the action of the input microwave signal, when a magnetic field is created whose level exceeds the threshold (H>Hcr2) there is a phase transition of the superconductor from superconducting S to normal (resistive) state N (so-called process-switching (switching)).
It has been established that it is possible to control the amplitude-frequency characteristic of a superconductor by a flowing voltage or current. That is, it is possible to build switches based on superconductors, which will be used in antennas, input circuits of cooled high-frequency paths and so on. The most practical are devices based on high-temperature superconductors, because their operating temperature is the temperature of liquid nitrogen, and the switching speed is less than 1 nanosecond. However, the use of guide systems requires consideration of their compatibility with standard devices and taking into account another number of features of the structure of microwave systems. That is, it makes sense to first separately analyze the operation of such switches, and then in the structure of the microwave system. The article studies the properties of only individual switches (phase shifters and limiters) on the basis of high-temperature superconducting thin films in order to develop principles and criteria that can be the basis for automated design of the considered high-speed superconducting microwave devices. To solve the calculation problem, the algorithm of analysis of resonant switching systems is used and the corresponding parameters and criteria are determined: transmission coefficients, modulations, attenuation, quality parameter, resonant characteristics (frequency, band, quality factor).
The results of calculations indicate the need for use in modern microwave systems of high-temperature superconducting high-speed broadband devices (phase shifters, limiters, delay lines, switches) that will reduce energy loses in the transceiver path, increase the speed of control of the antenna beam in space, increase noise, will increase the protective properties of the receiving tract from electromagnetic damage.
The article presents the results of calculations of the characteristics of switches made on the basis of superconducting microstrip transmission lines. The possibility of constructing high-speed (operating time less than nanosecond units) switches based on  superconductivity of films in the frequency range of 1−10 GHz with time (operating speed, recovery time), energy parameters (switching energy 10-10 J) and resonant characteristics (frequency, band, quality factor), which significantly outweigh the corresponding parameters of similar devices based on semiconductors.