Abstract
A frequency-reconfigurable antenna based on periodically loading ferroelectric MIM capacitors along a slot loop is designed, fabricated, and measured. The antenna is fabricated on a 430-µm-thick sapphire substrate with a total area of 1×1 cm2. The size of the slot loop is 2.5×2.5 mm2. By changing the bias voltage of the ferroelectric varactors from 0 V to 7 V, the resonant frequency of the varactor-loaded antenna can be tuned from 5.57 GHz to 7.33 GHz, corresponding to a tuning range of 27.3%, while keeping the return loss greater than 10 dB. At 5.57 GHz, the size of the slot loop is 0.046×0.046 λ02. When biased at 7 V, the antenna gain is −10.8 dBi at 7.35 GHz. Under 0-V bias, the Pin,1dB of the tunable antenna is 18.8 dBm at 5.6 GHz.
