Improved THz Reception by Non-Conventional Structure of Planar Dipole Antenna with Superconducting Josephson Junction Detector

Intensity and frequency of THz RF radiation are easily derived from superconducting Josephson junctions detectors I-V characteristics. The RF radiation generates current steps, correlated to intensity. The voltage at the steps renders accurately the RF frequency. DC measurements simplify significantly the detection systems. Implementing junctions in high temperature superconductors, requiring liquid nitrogen cooling only, reduces drastically operating complexity and cost. System efficiency is highly sensitive to impedance mismatch between antenna and low impedance junction. We propose improved planar dipole antenna structure, where the junction is placed between the ends of two strips, removed from the dipole. Theoretical RF analysis of the influence of junction parameters on input impedance was carried out. Extensive simulations of detection system were performed. High impedance matching was obtained for 195 to 215GHz, show high directivity, with radiation gain of 5. 22dB and low return losses of 35dB.