Contents I. Introduction
Phased array antennas have been predominantly used for military applications because of their extremely high cost. Emerging technologies and new microwave materials allow shifting the use of phased array antennas to the commercial market. The price of these antennas can be lowered effectively by application of phase control devices, implemented as MMIC. Nevertheless its final effectiveness this approach is long-term development process having in more cases two iterations. Successful way of mitigating this constrain is the development of low cost discrete phase shifter with acceptable dimensions. The major cost contributor in discrete and hybrid phase shifters operating in Ku band is the switching component - normally beam lead . diode. However, the diodes have relatively high power consumption, require special driving scheme and have relatively big switching time. Attractive alternative of this high quality but expensive component is a low cost discrete GaAs pHEMT FETs normally used in low noise down converters as amplifiers and active mixers. Precise measurement of cold FET two states S-parameters using TRL technique allows their use as a grounded switch in Ku band. The paper describes a patent pending discrete 5-bit phase shifter using new simplified configuration of less significant (LS) bit working in frequency range from 10.7GHz to 12.75GHz.
