Bandwidth Enhancement For Meander Dipole Antenna in MHz range

Abstract

This paper introduces design, fabrication and measurements for a printed meander dipole antenna with enhanced -10 dB bandwidth of 20 MHz (13%) in the VHF band. The antenna is fabricated on FR4 substrate with an overall compact area of 61.3 cm X 6.45 cm. The dipole antenna is composed of meander line terminated with a stub. Bandwidth enhancement is realized through two techniques; 1) resistive loading to the meander line, and 2) metal strips at the back side acting as capacitive loading. A parametric study is implemented for the position, values of the resistors and the dimensions of the metal strips to realize maximum bandwidth. Using resistive loading, the bandwidth is increased from 6.6 MHz to 12 MHz with efficiency 42 %. On the other hand, adding two metal strips further increases the bandwidth to 20 MHz with efficiency up to 56%. The antenna exhibits omnidirectional radiation characteristics over the operating frequency band 140-160 MHz. The proposed structure is fabricated, measured and compared to simulated results, where measurements are in good agreement with simulation results.