Electronically reconfigurable reflective phase shifter for circularly polarized reflectarray systems

摘要

This letter presents the design of a two-port electronically reconfigurable phase shifter for circularly polarized reflectarray systems at microwave frequencies. The phase shifter is based on 3 dB/90? couplers combined with reflective circuits that introduce sequentially the phase variation. Each reflective circuit, formed by printed elements (L) and tunable varactors, produces the phase variation due to the variable capacity value of the varactor. The phase shifting process includes three different stages of phase shifting for the signal in its way from the input port towards the output port through the phase shifter. Both ports are interchangeable, acting either as input or output ports. This fulfils the reflection requirements of circularly polarized reflectarrays, being especially suitable for this purpose. The complete design, together with its circuital behavior and performance results, are depicted in this document.