A W band superconducting heterodyne receiver with log-periodic antenna

A low noise superconducting Josephson junction heterodyne receiver (JJHR) with log-periodic antenna is proposed in this paper. The JJHR is designed working in the W band and the central frequency is 94 GHz. The Ansoft HFSS software is used to numerically calculate the performance index and it shows that the S ₁₁ parameter could be averagely less than -4 dB in the W band. At 94 GHz, the S ₁₁ value is decreased to -21.8 dB and the VSWR is 1.18, indicating good frequency response and impedance match at this atmospheric window frequency. The S ₁₁ parameter in the frequency range of 75 GHz to 300 GHz is also discussed and it performs that all the designed resonant frequencies of the log-periodic antenna are excited, confirmed by the E field distribution in the log-periodic antenna. The farfield pattern shows that the log-periodic antenna beam is perpendicular to the dielectric substrate and the main lobe is very broad, which could contribute to the wide airspace receiving.