A 585 GHz Quasi-Optical HEB Six-PortReflectometer Based on an Annular Slot Antenna

The 19th International Symposium on Space Terahertz Technology

R. Percy, L. Liu, H. Xu, J. Schultz, A.W. Lichtenberger, R.M. Weikle, II

Others  :  http://www.nrao.edu/meetings/isstt/papers/2008/2008550554.pdf
PID  :  3765

来源: CEUR

【 摘 要 】

— Six-port reflectometers have become a topic of interest due to the scarcity of instrumentation for measuringscattering parameters (s-parameters) at terahertz frequencies.This paper presents a quasi-optical six-port reflectometerdesigned for 585 GHz using hot-electron bolometers (HEB’s). Inthis design, a ring slot antenna couples a signal into thereflectometer creating a standing wave along a microstriptransmission line. The standing wave is sampled by three evenlyspaced HEB's. A polarization rotation resulting from the feed ofthe transmission line allows the antenna to act as both the inputand measurement ports (horizontally polarized energy iscoupled into the device and re-radiated with verticalpolarization). The reflectometer is expected to be sensitive tonanowatt power levels from 570 GHz to 640 GHz. The annularslot antenna and microstrip portion of the device have beenindependently fabricated and tested. This proof-of-concept testverifies that the polarization is rotated and provides an estimateof the power available for sampling. It was found thatapproximately 30 μW of power is available, as measured withan Erickson power meter. Simulations in conjunction with these