Planar circularly polarized X‐band array antenna with low sidelobe and high aperture efficiency for small satellites

Abstract

A planar broadband circularly polarized (CP) X-band array antenna with low sidelobe and high aperture efficiency is presented for small satellite applications. The array design is composed of 4 × 4 broadband CP stacked patch elements, which are fed by a feeding network consisted of unequal series-parallel power dividers to achieve the low sidelobe and high aperture efficiency. The final prototype with overall size of 100 mm × 100 mm × 3 mm (2.73λ 0 × 2.73λ 0 × 0.082λ 0 at 8.2 GHz) was fabricated and measured. The antenna has a broadband characteristic with |S 11 | < −10 dB bandwidth of 15.9% (7.52-8.82 GHz) and 3-dB axial ratio bandwidth of 11.95% (7.63-8.60 GHz). Also, it achieves an excellent broadside CP radiation with a gain of 17.2-20.03 dBic, a sidelobe level of <−20 dB, and aperture efficiency of 65% to 97.5%. With these features, the proposed antenna is a good candidate for high-speed data downlink onboard small satellites (MiniSat, MicroSat, NanoSat, and CubeSat). K E Y W O R D S aperture efficiency, circular polarization, low sidelobe, planar antenna, small satellite, unequal power divider

Antenna Designs for CubeSats: A Review

“…Moreover, the aperture coupled feeding can be combined with the concept of stacked patches where the top patch element is considered as parasitic. Hence, the coupling of resonances between the bottom fed patch and the top patch provides the broadband behavior as in the case of the X-band array on [27] that reported a bandwidth of 15.9%. For CubeSat applications, the authors of [12,25] used the aperture coupled feeding technique to enhance the bandwidth of their antenna designs.…”

“…These antennas operate in S, C, and X bands and provide a total gain ranging from 4.8 to 30.5 dBi. Amongst all patch antenna designs listed in Table 3, i.e., those in [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], the one in [15] and [16] have the smallest antenna physical size and hence they are suitable for use on 1U, 2U and 3U CubeSats. The design of [15] can also be implemented on the top of the solar cells because of its high transparency and hence allows for surface area reuse due to the integration of the antenna and solar cells.…”

“…In [27], Ta et al, presents a high gain X-band patch array antenna for small satellites including CubeSats to achieve high aperture efficiency and low side lobe CP. As shown in Fig.…”

Design of broadband circularly polarized metasurface antenna array with gain enhancement

“…[15][16][17] Among these antennas, the high-gain metasurface antenna has been widely used. [18][19][20][21] In Reference 21, the metasurface antenna with a periodic array of patch element had a 28% operation bandwidth, besides a maximum gain of 9.8 dBi.…”

“…Some researchers used metasurface antennas to reduce the antenna profile, expand the working band and improve the antenna directivity 15‐17 . Among these antennas, the high‐gain metasurface antenna has been widely used 18‐21 . In Reference 21, the metasurface antenna with a periodic array of patch element had a 28% operation bandwidth, besides a maximum gain of 9.8 dBi.…”