Size reduction of a liquid crystal-based, frequency-adjustable patch antenna

This study was aimed at miniaturizing an antenna functioning at 5 GHz. But, this miniaturization induces greater dimension errors in the realization phase, and thus shifts the resonance frequency. Among the possible solutions to cancel this drawback, one can put a liquid crystal under the patch to correct this frequency shift by a DC voltage. A first test device was, therefore, realized in planar technology with a low-cost foam substrate. Then, we have simulated and measured an antenna miniaturized by inserting slots. These results are compared to the experimental ones produced by the first device.