Oral Presentation

Local Oscillator Power Distributor for sub-mm Wave Receiver Based on SiNx/Si Membrane Technology

Author(s): Yan-Jun Wang1,2, Yen-Ping Chang2, Wei-Chun Lu2, Jia-Ruei Nian2, Yau-De Huang2, Tse-Jun Chen2, Ming-Jye Wang2 1 Graduate Institute of Astrophysics, NTU 2 Institute of Astronomy and Astrophysics, AS

Presenter: Yan-Jun Wang (Graduate Institute of Astrophysics, National Taiwan University, Taipei 10617, Taiwan)

Observation time of world-class radio telescope gets more and more precious in this pursuing diverse object and high-resolution era. Multi-pixel receiver is one of the ways to increase the current radio telescope’s mapping speed and reduce the observation time of each target. A compact and easy to be scaled up multi-pixel receiver module is crucial. In this poster, we will present our study on LO (local oscillator) power distributers work at the frequency from 200GHz to 240GHz, which is based on SiNx/Si membrane structure.
We designed a 1-to-2 LO power divider as our starting point. A 1-to-1 LO power coupler is also designed as the baseline. The LO power divider include a transition probe (emitter) on SiNx/Si membrane in waveguide, the CPW, and Wilkinson power divider in CPW form. The design of these elements was simulated by an EM simulator, HFSS®. The calculated S11 and S21 (S31) of power divider would be below -22dB and higher than -5dB respectively. To realize the SiNx/Si membrane structure, we performed Si wet-etching process in KOH solvent. The preliminary result follows our expectation. However, how to protect the frontside circuit (Nb film) is still under investigation.