X-Band Dual Circularly Polarized Patch Antenna With High Gain for Small Satellites

Abstract

This paper presents an X-band circularly polarized patch antenna with a simulated high gain of 12.5 dBi and a simulated side-lobe-level of below −20 dB, within the bandwidth of 5.2 %. This single element antenna achieves high gain by exploiting the mode superposition of TM 11 + TM 13 (excited by a circle of vias loading the cavity) and TM 12 + TM 14 (excited by the cavity itself) radiated from the two apertures, respectively. A simple feeding network, consisting of a quadrature hybrid and a couple of 90 • bent branches, is used in the design to excite RHCP or LHCP mode in the antenna cavity. A capacitive disk feeding is implemented so that the antenna can be matched to the feeding network, and the super-positioned fields inside the cavity are not disturbed by the feeding pins. This approach makes the design of a dual-sense circularly polarized antenna with high gain easier since the array configuration is not needed. High gain, in combination with a dual-sense circular polarization, makes the proposed antenna particularly attractive for space applications involving small satellites. With the proposed design, it is possible to employ only one antenna rather than two (RHCP and LHCP), thus saving space on the aircraft, which is clearly a limited resource.INDEX TERMS Circular patch, circular polarization, high gain, sidelobes suppression, small satellites.

Meta‐surface loading broadband and high‐aperture efficiency dual circularly polarized patch antenna

“…Patch antennas have attracted lots of attentions benefiting from their superiorities of ease of fabrication, low profile, easy realization of circular polarization, good compatibility with microwave passive and active circuits, 19 etc. Square radiation patches 20‐22 or circular radiation patches 23 are excited with orthogonal feeding ports by employing quadrature couplers, forming dual‐CP radiation. A CPW transmission feeding line patch excited by even and odd mode ports realizes dual‐CP within a compact solution 24 .…”

A Compact Dual Circularly Polarized Antenna With Wideband Operation and High Isolation

“…In the open literature, many designs have utilized a branch line coupler as an effective method to achieve dual circular polarization [17][18][19][20][21][22]. The coupler ensures having two output signals equal in magnitude with 90° phase shift needed for CP generation.…”

“…Using a hybrid coupler as feeding structure, the antenna can provide either left-hand CP (LHCP) or righthand CP (RHCP) depending on the excited port. Although wide AR BW can be conveniently accomplished in [17][18][19][20][21][22] by this method, the most challenging aspect is the poor interport isolation. The literature review has found that the best performance in the operating BW is only about 15% [17] with isolation of better than 15 dB, where the radiating patch is coupled to the coupler through double H-shaped slots.…”

“…The literature review has found that the best performance in the operating BW is only about 15% [17] with isolation of better than 15 dB, where the radiating patch is coupled to the coupler through double H-shaped slots. Meanwhile, the limited BW with high isolation in the designs in [18][19][20][21][22] might not be particularly appealing for wideband applications.…”

“…The method of using a branch line coupler to excite a square microstrip patch for dual-sense CP operation is employed. However, unlike the conventional designs [17][18][19][20][21] in which the coupler is separated from the radiating elements by the ground plane, the coupler in the proposed design is positioned between the radiating element and the ground plane. Additionally, a set of metallic plates is also placed periodically around the driven patch and acts as parasitic elements, which provide more degrees of freedom in optimizing the antenna performance for a wide BW.…”