High-temperature superconducting materials has demonstrated great potential of major performance breakthrough in microwave and millimeter wave (mm-wave) components and subsystems for fast growing wireless communication, sensing and space industries.  In particular, the surface resistance of HTS material is about 100-1000 times less than conventional metals such as copper and silver at microwave frequencies, and therefore they are the ideal materials to develop “super filters” with ultra-high performance, typically low insertion loss, narrow bandwidth, high stopband rejection, and steep skirt slopes. Additionally, the low-noise Josephson junctions made from HTS thin films features extreme nonlinearity of the current-voltage (I-V) relationship, which is highly attractive for applications in active microwave devices, such as oscillators, amplifiers and mixers. Such superconducting active devices feature extremely low noise, broad band, and high frequency operation (microwave to THz range), and low power consumption.

Major research efforts and achievements have been made on HTS passive circuits in the past two decades, resulting in the application of HTS receivers for various wireless systems, including mobile communications, space communications and radar systems. However, the full benefit of HTS circuits cannot be realized if only HTS filters are implemented in the receiver systems. An all-HTS circuit with HTS passive and active components integrated monolithically would greatly improve the receiver performance due to more efficient signal coupling, the low loss of HTS transmission lines, and low noise of Josephson junctions. Additionally, Josephson mixers feature low power consumption due to the low DC biasing current at μA level, and low LO powers requirement (microwatt level), which, together with more compact size, would greatly reduce the overall power consumption of the cryogenic receiver front-ends.

In recent years, significant progress has been made by the authors’ group in developing various HTS high-frequency devices and circuits including HTS microwave filters, THz antennas and detectors, Josephson mixers and on-chip monolithic HTS receivers. The active devices were made using the CSIRO patented step-edge junction technology and some have demonstrated the performance superior to their kinds reported in literature. New modelling techniques have also been developed to optimize the HTS circuit designs and device performance. Very good agreements were achieved between the simulation and experimental results. These novel devices have been successfully applied to THz signal detection, THz imaging, and wireless communication front-end receivers from microwave, Ka-band to THz bands. In this talk, we will give an overview of the recent activities and achievements on developing HTS microwave, millimeter-wave and THz communication mixer and receiver technologies.