Four-element varactor diode loaded polarisation-agile microstrip antenna array

摘要

A square, varactor diode-loaded polarisation-agile microstrip patch, radiating either circular polarisation (left or right hand) or linear polarisation (in two orthogonal planes) is described. A linear array comprising four such patches has been designed. Measurements show, when operated in circular polarisation, axial ratios better than 0.5 dB and, in linear polarisation, cross-polar levels better than -20 dB.