FDTD analysis of printed square spiral antennas for wireless communications

The progress in personal communication services calls for the development of various types of compact antenna units mounted on handheld/mobile devices. The printed spiral antenna is a good candidate for such applications since it has nearly constant input impedance over broad frequency ranges and radiates circularly polarized waves within the desired operating bandwidth. The finite difference time domain (FDTD) analysis for the radiation pattern and input impedance of a printed 2-arm square spiral antenna is presented in an attempt to demonstrate the feasibility of using the FDTD technique for the design and performance evaluation of this class of antennas.