Analysis of parallel plate dipole sensor using finite difference time domain method

A parallel plate dipole (PPD) sensor has been analysed using a direct three dimensional finite difference time domain (FDTD) method. The various electrical parameters of the PPD sensor derived using this method are: (a) the sensor response to a double exponential transient wave and a Gaussian pulse, (b) the sensor capacitance, (c) the equivalent length, (d) the equivalent volume, and (e) the figure of merit. The variations of these parameters with the structural dimension of the sensor are determined and compared with that obtained by the conventional electrostatic method. Finally the effect of a dielectric shell (used for the mechanical protection of the sensor) on the equivalent length and the response of the sensor are analysed and discussed.