Design and simulation of a wideband on-chip terahertz spectrometer

Superconducting on-chip spectrometers have both imaging and spectroscopic capabilities. In general, the broadband signal coupled from an antenna goes through frequency dispersion via a series of filters that are connected with superconducting detectors like kinetic inductance detectors or bolometers. The filters have the same relative bandwidth, which determines the frequency resolution of the spectrometer. We here present the design and simulations on the twin-slot antenna, CPW-to-microstrip transition, and a ten-channel filter-bank of a verification-stage terahertz spectrometer chip at 350 GHz. The simulation results of the antenna and transition showed low return loss, and the simulation results of the ten-channel filter-bank show that each channel has good readout independence and coupling strength. These designs and simulations can provide assistance for the future development of terahertz on-chip spectrometer.