A low-profile dual band, dual polarised array antenna module

Describes the design of a microstrip patch antenna module intended for use in X-band satellite communications as a building-block for a variety of two-dimensional array antennas. The module can operate in duplex mode in dual orthogonal circularly polarised transmit/receive bands. The total bandwidth is about 15%. The antenna consists of a microstrip layer containing four circularly polarised patches, each with two orthogonal feed points, and a triplate layer containing a dual feed network and separate transmit/receive connectors. The patches are excited via pins connecting the two layers. The principles of sequential rotation are employed to achieve the broadband performance. The whole structure is bonded together as a sealed unit and is suitable for mass production