A Folded Printed Quadrifilar Helical Antenna Employing a Compact Feeding Network

Abstract

Abstract-A folded printed quadrifilar helical antenna (FPQHA) with an integrated and compact feeding network is proposed. The axial length of the proposed antenna is miniaturized of about 54.7% than the conventional PQHA by folding the helix arms into several elements. A T-junction power divider combining with two Wilkinson power dividers is utilized to feed the antenna. A fabricated prototype of the FPQHA using the compact feeding network is presented. The measured positive gain bandwidth covers 380-430 MHz with the reflection coefficient below −20 dB, axial ratio below 1.5 dB and a half-power beamwidth of about 120 • . Details of the proposed antenna design and experimental results are presented and discussed.

Wide‐beam spiral antenna with three folded arms fed by compact three‐way Wilkinson power divider

“…Resonant quadrifilar helical antennas (QHAs) are the most investigated structure for this purpose. Meanwhile many configurations are introduced for QHAs to reduce the size of antenna such as QHAs with meandered or folded arms, conical QHAs, conical QHAs with folded arms [1][2][3][4] etc.…”

“…The feed network consists of only a compact three-way Wilkinson power divider (PD) and the additional microstrip lines. Total size of the feed network is smaller than previous reports such as [1,4]. The antenna and feed network are designed and studied for 435 MHz and simulation results are validated by measurement.…”