Ultra-Wideband Air-Filled SIW Cavity-Backed Slot Antenna with Multipolarization Reconfiguration

Air-filled substrate integrated waveguide (AFSIW) cavity-backed slot antenna topologies are promising candidates to address the specific design challenges posed by the Internet of Things (IoT). In this contribution, we demonstrate a new single-feed ultrawideband cavity-backed slot antenna with multipolarization reconfiguration by leveraging four quartets of PIN diodes in substrate-independent AFSIW technology for operation in the [5.15-5.85] GHz frequency band. To achieve ultra-wideband performance, two concentric annular slots are created on the top of the circular cavity. By electrically shorting these annular slots at well-defined positions by the aforementioned PIN diodes, dynamic polarization reconfiguration is achieved by switching their DC bias current. Moreover, a systematic investigation of the different loss contributions and power consumption is performed. A physical explanation of the different effects is also provided. Finally, a fabricated prototype exhibits a measured impedance bandwidth of 1.6 GHz (or 29%), a total efficiency higher than 74%, and a gain higher than 5.2 dBi for all four states in free-space conditions.

Automated summary

This article introduces a new single-feed ultrawideband cavity-backed slot antenna with multipolarization reconfiguration. By creating two concentric annular slots on the top of the circular cavity and shorting them at specific positions using four groups of PIN diodes, dynamic polarization reconfiguration is achieved. Experimental results show that the antenna has an impedance bandwidth of 1.6 GHz (or 29%), total efficiency higher than 74%, and a gain higher than 5.2 dBi in free-space conditions.