Ka-Band AFSIW Circuit-on-Substrate for Satellite Applications

This paper presents the demonstration of a circuit on substrate utilizing high-performance passive components based on the air-filled substrate-integrated waveguide (AFSIW) technology. A receiver module, designed for space applications and operating in the satellite Ka-band frequency range (27.5 to 30.2 GHz), is introduced. This module integrates both passive and active functions on a single multilayer PCB. The passive functions include rectangular waveguide-to-AFSIW transitions, circulators, loads, GCPW to AFSIW transitions for interconnecting surface-mount low noise amplifier (LNA), and a bent 8th-order bandpass filter for compactness. The design of each passive component is introduced, followed by the integration and fabrication on a demonstrator. Experimental results validate the circuit's performance, with an achieved gain of 35.1 ± 1.76 dB, a return loss better than 14.7 dB, and a noise figure (NF) of 4.97 ± 0.64 dB within the frequency band of interest.