Frequency-reconfigurable single-layer design of microstrip patch electrically-steerable parasitic array radiator(ESPAR)

Abstract

A novel frequency-reconfigurable ESPAR phased array antenna with beamsteering capability is presented in this paper. ESPAR antennas can realize beam scanning by dynamically changing the load impedance of the parasitic antenna element or the coupling capacitance between the driven and parasitic antennas. However, current ESPAR antennas lack the frequency tuning capability and therefore the useful frequency range is limited. Herein a frequency-reconfigurable ESPAR antenna is realized by providing frequency control on both driven and parasitic antenna elements. In full-wave simulations, it is shown that this ESPAR phased array antenna is able to change its resonant frequency from 0.87 to 0.95 GHz, which significantly extends the frequency range from a frequency-fixed ESPAR. In addition, at each operation frequency, this ESPAR is able to steer the beam from -20 to 20 degree, which is comparable to the beamsteering range of a frequency-fixed ESPAR.