Circularly Polarized S-Band Satellite Antenna With Parasitic Elements and Its Arrays

Design approach to a novel balanced, circularly polarized (CP) square loop antenna under even‐mode resonance is proposed in this paper. The loop antenna is diagonally fed by a fork‐like dipole launcher. By matching the respective natural boundary condition of the loop radiator and the dipole launcher, the resonant even‐mode with inherent CP radiation characteristic can be sufficiently excited. Both the bi‐ and uni‐directional cases are designed and investigated. A bi‐directional CP loop antenna with a 3‐dB ratio axial ratio (AR) bandwidth of 6.6% is designed at first. A uni‐directional antenna having a planar metallic reflector is further designed. The uni‐directional loop antenna exhibits excellent uni‐directional CP performance with a high front‐to‐back ratio of 40dB and a 3‐dB AR bandwidth of 7.6% in both theory and experiment.

Section: Introductionmentioning

confidence: 99%

Balanced circularly polarized square loop antenna under even-mode resonance

Yuan

Gao

et al. 2018

“…These approaches can be basically categorized into five distinctive types in terms of operation principle. The first one is the parasitic component technique . By making use of parasitic elements, the half‐power beamwidth (HPBW) of an air‐substrate patch antenna can be broadened to about 85°, which is much wider than the typical one (ie, 60°) of a square patch antenna .…”

Section: Introductionmentioning

confidence: 99%

Wide beamwidth planar self‐balanced magnetic dipole antenna with enhanced front‐to‐back ratio

Shen

et al. 2020

A design approach to a novel planar self‐balanced, wide beamwidth magnetic dipole antenna with high front‐to‐back ratio (FBR) is advanced. The principle for FBR enhancement is revealed at first. As seen, the back‐lobe level can be effectively suppressed by adjusting the unbalanced current ratio (UCR) factor: By varying the radius of the circular sector magnetic dipole antenna on the bottom layer and incorporating an arc‐shaped branch at the end of the parasitic strip, the UCR factor can be properly tuned, and the back‐lobe level can be flexibly controlled. Then, a set of closed‐form formulas is derived to provide basic design guidelines and determine the initial value of key parameters. Parametric studies on FBR are then carried out to attain the ultimate designs in a step‐by‐step manner. As numerically and experimentally verified at the 2.45‐GHz band, the FBR of a planar, air‐substrate magnetic dipole antenna is indeed increased to over 30 dB with broadened E‐/H‐plane half‐power beamwidth up to 130°/90°. Good agreement between the theoretical, numerical, and experimental results has evidently validated the proposed antenna design approach.

“…CP antennas with wide 3 dB axial ratio beamwidth (ARBW) and hemispherical radiation pattern are highly demanded to increase coverage and receive signals even at low‐elevation angles effectively . For example, a GPS terminal antenna needs to receive signals from at least four satellites to determine a 3‐D location.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5] CP antennas with wide 3 dB axial ratio beamwidth (ARBW) and hemispherical radiation pattern are highly demanded to increase coverage and receive signals even at low-elevation angles effectively. 6,7 For example, a GPS terminal antenna needs to receive signals from at least four satellites to determine a 3-D location. As a result, the terminal antenna generally should be designed to have wider vertical half-power beamwidth (HPBW) and higher gain for low elevation angle.…”

Section: Introductionmentioning

confidence: 99%

Novel wide-beam cross-dipole CP antenna for GNSS applications

Zhang

Qin

et al. 2018

A wide‐beam circularly polarized (CP) cross‐dipole antenna for GNSS applications is proposed in this article. This cross‐dipole antenna is fed by a coaxial cable, on which the slots is added to optimize the impedance matching. These two pairs of dipole arms are designed with different lengths to obtain the circularly polarized radiation. Enhanced wide‐beam CP radiation characteristics can be achieved by curving the dipole arms and adjusting the distance between the arms and the metallic ground plane. The study of proposed antenna performance with different geometric parameters has been conducted. The final antenna exhibits a good impedance bandwidth (IBW) of ∼13.1% (1.50‐1.71 GHz), and the 3‐dB axial‐ratio bandwidth is over 7% (1.52‐1.64 GHz). Broad pattern coverage of more than 140°, pure CP radiation at all designed bands and a wide 3 dB axial‐ratio beamwidth (ARBW) of nearly 150° makes this antenna an excellent candidate for satellite communications and navigation systems.