Módulos de conmutación de fase de 4 estados en banda Q para radioastronomía

Abstract

Two greater than 30% relative bandwidth phase shifters with four phase states are designed to be integrated in a radio astronomy receiver at Q-band. Two different circuit topologies are presented in order to fulfil requirements. The first circuit is based on planar structures and PIN diodes, while the second design is based on waveguide phase shifters and SPDT MMICs. The planar circuit consists of two 90º out-ofphase microwave phase-shifting branches which are combined by Wilkinson power dividers; each branch is composed of a 180º phase shifter and a band-pass filter. The waveguide solution is based on cascaded 180º and 90º individual phase shifters. Both designs have been manufactured and their experimental characterization have shown significant results, making them suitable for being part of a radio astronomy receiver.