An Electrical Frequency Agile Patch Antenna Based on a Poly(vinylidene fluoride-trifluoroethylene) Thin Film

A novel scheme of an electrically tunable microstrip patch antenna using an electroactive polymer Poly(vinylidene fluoride-trifluoroethylene) thin film as a part of substrate is presented. The suited plus DC power supply is produced and applied to adjust the permittivity of the Poly(vinylidene fluoride-trifluoroethylene) film, which is imposed directly on the copper patch of the antenna. The patch is designed to be the same size as the ground plane to guarantee the plus static electric field inside the film uniformly. With the proposed structure, an electrical frequency agile microstrip patch antenna that performs well is achieved. The measured results demonstrate that the resonant frequency can be unceasingly tuned from 3.72 to 4.025 GHz; when the DC voltage changed from 0 to 430 V, a frequency tuning range of 7.57% is obtained.