A tunable multiband folded printed quadrifilar helical antenna (FPQHA) is proposed. Creating slot on the arms of FPQHA is a simple approach for designing multiband helical antenna. Also varying width and length of the slot can cause to tune the interested frequency bands. The operating frequency ranges in L/S/C band that covers L1 GPS band and most of the commercial wireless communication systems, such as WLAN [IEEE 802.11 (2.4/3.6/5 GHz)], LTE and WiMAX (2.5/3.5 GHz).

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This article presents a novel reflective phase shifter based on wideband multi‐section 3‐dB hybrid coupler in slot‐coupled structure. By terminating coupled and transmission ports of coupler with rectangular microstrip loads, reflective phase shifter is achieved. It designed on multilayer Rogers RO4003C substrate. The configuration consists of elliptically shaped transmission line and the combination of rectangular and elliptical shaped slots on the ground plane. To improve characteristics of the designed coupler especially in lower frequency band, multi‐section transmission line and altering shape of the slot on ground is proposed. By etching extra rectangular slots on the ground plane the overall size reduction is achieved. Measurement results of the proposed coupler demonstrate coupling of 3 ± 0.7 dB with 90° ± 0.6 phase shift over 1–6 GHz (143%). The novel reflective phase shifter based on the designed coupler provides phase deviation less than 0.7° on 1.2–4.8 GHz (120%). The obtained return loss is better than 10 dB as well as insertion loss is less than 1.2 dB at the frequency band of interest. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:567–573, 2017

A wideband printed quadrifilar helical antenna (PQHA) using a novel single layer compact feeding circuit is proposed in this paper. A low-cost single-layer feeding circuit which consists of a 180 • compact rat race coupler and two 3 dB hybrid commercial couplers is incorporated at the bottom of the quadrifilar antenna. The antenna arms are tapered at the feeding point to improve impedance matching between the antenna and feeding circuit. The operating frequency band ranges from 1.9 to 2.3 GHz which shows that the proposed antenna is a good candidate for various applications such as satellite communication and broadcasting satellite systems. Therefore, the array of the proposed antenna on the simple cube satellite mock-up is investigated. By this antenna array configuration, a fully spherical radiation coverage is obtained around the structure. The bandwidth of the axial ratio (AR) with a wide beamwidth (160 o) is 20% in operating frequency band. The measured peak gain of the proposed antenna varies between 2.6 and 3.2 dBic in the frequency band of interest. The measured 3 dB AR half-power beamwidth is 160 • .