Radial Line Patch Array Antenna with Enhanced Circularly Polarized Beam-Steering Performance for K-Band Fixed Radio Links

This paper presents a design procedure for circularly polarized radial line patch array antennas that allows the steering of the main beam whereas the axial ratio is not drastically affected. This method is an extension of a previous publication, in which the radiated phase of each element was adjusted by rotation depending on its position in the lattice. This way, a partial sequential rotation is included. The used radial line patch array antenna is composed by double stacked patches as radiating elements. The design procedure allows to perform any of the two circular polarizations at K-Band (19.7 - 20.2 GHz) for SATCOM. An axial ratio below 2.2 dB for a ±30° steering angle in the azimuth and the elevation plane is achieved, with a gain decay of 2.5 dB with respect to broadside. All the configurations exhibit a good behaviour in terms of efficiency, with values near to 90%.