Single Layer Extensible Microstrip Array Antenna Integrating SPDT Switch Circuit for Linear Polarization Switching

A single layer extensible microstrip array antenna integrating a Single Pole Double Throw (SPDT) switch circuit for linear polarization switching is proposed, and the characteristics of the array antenna are investigated. The proposed array antenna consists of a dual-polarized microstrip array antenna and a novel SPDT switch. The SPDT switch has four diodes, a ring-slot and microstrip lines actively using both-sided MIC technology. By using the SPDT switch, the array antenna can switch the ${\pm 45}mathchar$ linear polarizations accurately. It has a design flexibility to extend to antenna arrays such as 4 $,\times,$ 4 and 8 $,\times,$ 8 arrays and so on. It is verified experimentally that the array antenna has an excellent basic performance of linear polarization switching. The array antenna is very promising in a wide variety of wireless application areas, such as radar systems and various kinds of RF sensors. Therefore, it will be pragmatically attractive for various kinds of wireless applications.