Single-, Dual- and Wide-Band Frequency-Reconfigurable Antenna with Annular Ring Slots

This paper presents a frequency reconfigurable antenna enabled using a pair of annular ring slots on a coplanar waveguide (CPW) ground plane. Its initial wideband operation mode from 3 GHz to 6 GHz can be reconfigured into six additional modes: a dual–band mode and five single-band modes, with minimum reflection coefficients (S11) of -10 dB. For demonstration and proof-of-concept purposes, metal switches have been used to represent the switches in simulations and measurements. The ON state is emulated using shorted metal switches, whereas the OFF state is emulated using an open. Good agreements are indicated for simulated and measured S11 and radiation patterns.