WAVEGUIDE COMPONENTS DEVELOPMENT FOR APEX 1.32 THz RECEIVER
D. MELEDIN, A. PAVOLOTSKY, M. PANTALEEV, C. RISACHER, V. BELITSKY

Abstract. We develop a waveguide balanced Terahertz mixer for 1 250–
1 390 GHz operation frequency range as a part of the Atacama Pathfinder Experiment (APEX) Project. The proposed mixer employs balanced scheme with two identical mixers chips fabricated on two separate crystalline quartz substrates with dimensions of 1 000 µm x 67 µm x 17 µm each with integrated RF choke filters, DC-bias and IF circuitry. We have designed a 3 dB quadrature waveguide directional coupler to achieve the required frequency band, low insertion loss and symmetrical division of the RF and local oscillator (LO) power within the band of interest. In order to achieve best performance, fabrication of the directional coupler for the waveguide THz balanced receiver has been done using micromachining approach combined with electroplating.