Frequency Reconfigurable Compact Multiband Quasi-Log Periodic Dipole Array (QLPDA) Antenna for Wireless Communications

摘要

The log-periodic dipole array (LPDA) antenna is most commonly characterized as providing a linearly-polarized and directive radiation pattern across a wide frequency band. Methods of designing and analyzing basic LPDA structures have been discussed at length by Carrel and Peixeiro [1]. The LPDA structure has long been used for wideband VHF and UHF communication applications [2]. More recently, the LPDA structure has been presented using standard PCB materials as a substrate for low cost applications [3-5]. There is great demand for frequency reconfigurable multiband and compact antennas in modern mobile handheld communication units that can work with arbitrary orientation of the receive wave. Presented herein is the simulation design of a microstrip quasi-LPDA antenna utilizing RF switches for providing frequency reconfiguration and acceptable omni-directional radiation patterns at the desired multibands. Tuning these frequency bands to a specific communication application would allow the antenna designer to ensure that energy radiates in the desired band while attenuates in the undesired frequency bands. The full wave analysis has been performed using the Ansoft Corporation's High Frequency Structure Simulator (HFSS) which is a finite-element-method (FEM) based commercial tool [6]. The antenna will be fabricated and experimentally verified and the results will be presented during the symposium.