Hysteresis effect in microwave power transmission of high temperature superconducting coplanar transmission lines

Abstract

We have observed an unusual hysteresis loop in rf power dependence of high-temperature superconductor (HTS) coplanar transmission lines. At 77 K and 1 GHz, the signal transmission was linear (insertion loss <0.1 dB) until the input power (Pin) reached a critical value of Pc=0.4 W. An abrupt drop by ∼37 dB in the transmitted power (Pout) was observed at Pin=Pc followed by a slow increase (Pout∝Pin0.62) for Pin≳ Pc. As Pm was then decreased, it retraced the previous curve only until Pin=Pc. However, as Pin was reduced further Pout did not rise until Pin=158 mW, at which Pout started to increase rapidly and returned to the linear regime for Pin<71 mW. Such a sharp transition and a strong hysteresis effect were unique to the HTS line whereas a gold line with an identical structure did not exhibit these characteristics. This behavior may be utilized for potential applications of new HTS microwave power (current) limiters and switches. Several possible origins for the hysteresis effect are proposed and discussed.

Numerical computation of the interaction between electromagnetic waves and nonlinear superconducting materials

“…It should be mentioned that the proposed model does not take into account the hysteresis effect, which has been recently experimentally shown for HTSs [37].…”

Measurement of dielectric loss tangent at cryogenic temperature using superconducting film resonator

“…The resonator is then placed inside a small cavity made of oxygen free high-conductivity copper (OFHC) which is gold (purity [99.9 %) plated to minimize the radiation loss. The details of this device are well described in some references [15][16][17][18][19][20] [10][11][12][13][14]. The ceramic was sintered by traditional powder processing method [1][2][3].…”

“…Because only the value of the quality factor is sufficient to infer the loss tangent, a calibrated measurement is not required. The input source power should be chosen neither too large in case of the nonlinear effect [16,20], nor too small to get a good signal to noise ratio of the S 12 or S 21 signal intensity. It should be kept above 10-15 db to measure an accurate 3-db bandwidth of the transmission coefficient.…”

“…Superconducting parallel plate resonator (PPR), a parallel plate capacitor structure with two superconducting films back to back and a dielectric spacer between them was first introduced by Taber [15] to measure the RF surface resistance of superconductor films. This method was then extensively utilized in research studies [16][17][18][19][20][21][22]. In this manuscript, we, in another point of view, will demonstrate that this device can also be used to measure microwave loss tangent of any dielectric materials at cryogenic temperature range with great advantages over the commonly used TE 01d metal cavity method [1,2].…”

The study and simulation on superconducting parallel plate resonator

“…The incident microwave power was chosen at 1 mW to avoid the high-power nonlinear effect [8]. Optimum coupling was obtained in the undercoupled regime so that the loaded and unloaded Q were essentially indistinguishable.…”