Wideband circularly polarized his backed fan‐shaped antenna with directional patterns covering L1‐L5 GPS bands

Abstract

ABSTRACTA wideband circularly polarized (CP) fan‐shaped antenna employing a sequential phase feed network (SPFN) covering L1 to L5 global positioning system (GPS) bands is presented. The antenna geometry consists of two crossed bow‐tie shaped dipoles with four arms which offers bidirectional CP radiation. A SPFN feeds dipole arms with equal amplitudes and 0°, 90°, 180° and 270° phase values. To achieve directional patterns, the bidirectional antenna is backed by a mushroom‐like electromagnetic band gap (EBG) structure which serves as wideband high impedance surface (HIS). Measurement verifies that the HIS backed antenna offers acceptable impedance matching, axial ratio (AR), antenna efficiency, gain and pattern performance between 1170 MHZ to 1630 MHZ (around 32% fractional bandwidth). The measured broadside (θ = 0°) AR is below 3 dB from 1.15 GHz to 1.7 GHz (38% bandwidth). The directional RHCP measured de‐embedded gain is 5.8 dBic, 6.1 dBic, 5.5 dBic and 4.6 dBic at 1170 GHz, 1220 GHz, 1380 GHz and 1570 GHz, respectively. The de‐embedded antenna efficiency is better than 60% between 1.15 GHz and 1.6 GHz with the maximum of 90% at 1.4 GHz. The measured and simulation results agree very well. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:497–500, 2017