Affordable sub-THz band-pass mesh filters

This paper describes a design and realization of an affordable band-pass mesh filter as an element of a cheap sub-THz band spectrometer. The complete spectrometer system is to be built of a number of detectors of the THz radiation based on metal-oxide-semiconductor field-effect transistors monolithically integrated with planar narrow-band antennas fabricated on a thin substrate. The role of the filters is to precisely control the operating frequency of each pixel. Because of high number of the detectors fabricated as a tightly-spaced detecting line (or an array) many filters tuned to different frequencies are needed. The proposed solution allows to easily manufacture many such filters in a single piece of metal foil forming a filter bank without increasing the price of the element.