Design of a DPA based on the dual‐level supply voltage modulation for efficiency improvement

Abstract

150 C. Dielectric characteristics of the substrate, permittivity ( r 5 2:029Þ and dielectric losses (tand 5 0.084) have been extracted using a ring resonator for the paper substrate of 250 lm thickness. These parameters have been used in HFSS simulation for designing two antennas, a broad side patch antenna and an end fire radiation quasi-yagi antenna, with resulting efficiency 55% and 45%, respectively. The antennas are quite narrow band around a central frequency of 2.4 GHz and correspond to the most common needs for WSN on trains. 2. M. Grud en, A. Westman, J. Platbardis, P. Hallbj€ orner, and A.Rydberg, Reliability experiments for wireless sensor networks in train environment,