Monolithic Co-Design of a 15 GHz SPDT-Antenna Allowing Polarization Reconfigurability

This paper presents a new co-design of a 15 GHz SPDT -antenna for RF seekers. The SPDT -switch permits the commutation between the two possible feeding paths of the antenna and, therefore, a switch able polarization between two linear (horizontal and vertical) ones in order to optimize the detection of targets in future RF seekers. Thanks to the silicon substrate, the active elements, i.e., N+PP+ integrated junctions, and the passive parts, i.e., transmission lines and the antenna, are designed and optimized at the same time, which gives some flexibility and degrees of freedom. The flexibility is given by the possibility to choose the doped-areas size and their position avoiding off-the-shelf components that induce parasitic effects at high frequency. The reconfigurability is achieved using integrated semiconductor distributed doped areas (ScDDAs), forming N+PP+ integrated junctions with a chosen length as long as possible to optimize their performances. Firstly, the concept of the SPDT- antenna is discussed followed by the design, the simulations, the fabrication and ending by the measurement of the demonstrator.