# A Spaceborne Integrated S/Ka Dual-Band Dual-Reflector Antenna

## TL;DR

This paper introduces a dual-band satellite antenna that efficiently supports both low and high data rate communications using innovative design techniques.

## Contribution

The novel use of a frequency-selective surface sub-reflector and miniaturized radiating elements enables efficient dual-band operation in a compact satellite antenna.

## Key findings

- The S-band channels achieved gains exceeding 20.2 dBic with beamwidths over 6°.
- The Ka-band channel achieved gains over 41.2 dBic with beamwidths greater than 0.8°.
- The design effectively reduces aperture blockage and improves mechanical layout feasibility.

## Abstract

To address the diverse requirements of satellite communication applications involving medium-/low-rate reliable links and high-rate high-capacity services, an integrated S/Ka dual-band dual-reflector antenna is proposed as an effective solution. Owing to the stringent spatial constraints of satellite platforms, the longer operating wavelengths in the S-band lead to oversized feed horns in the integrated antenna design, which induces severe secondary aperture blockage, thus degrading aperture efficiency and impeding practical mechanical layout implementation. To alleviate this critical drawback, the proposed antenna achieves multi-band aperture reuse by deploying an array with four miniaturized S-band radiating elements around a broadband Ka-band feed horn. A frequency-selective surface (FSS)-based sub-reflector is further designed to effectively enhance the effective aperture size for the S-band operation, while ensuring unobstructed electromagnetic propagation in the Ka-band, thus enabling simultaneous dual-band high-gain radiation. After comprehensive electromagnetic simulation and parametric optimization for the antenna feed and the FSS sub-reflector, experimental measurements verify that the S-band left-hand and right-hand circularly polarized (LHCP/RHCP) channels achieve more than 20.2 dBic gains with more than 6° half-power beamwidths (HPBWs), and the Ka-band channel yields gains exceeding 41.2 dBic, with HPBWs greater than 0.8°.