Compact Substrate Integrated Waveguide Quasi-Endfire Antenna for CubeSat Integration

Abstract

A planar quasi-endfire surface-wave antenna (SWA) using substrate integrated waveguide (SIW) technology for integration with CubeSats and other small satellites is proposed in this letter. This antenna can be attached to the body of the satellite, resulting in a compact and low-cost design. A quasi-endfire beam pattern is achieved by the radiation of the fundamental TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_0$</tex-math></inline-formula> surface wave mode at the edge of a grounded dielectric slab (GDS). This mode is excited by a leaky SIW T-junction creating a uniform wavefront that propagates through a truncated parallel-plate waveguide (PPW). A matching section based on an array of subwavelength patches is also added at the interface between the PPW and the GDS for reduced reflections and improved antenna radiation performance. The measured prototype demonstrated realized gain values of 13.3 dBi at 18.6 GHz for a competitive structure size of 5 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lambda _0$</tex-math></inline-formula> × 4.8 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lambda _0$</tex-math></inline-formula> and with a simulated total radiation efficiency of 93.4%, providing high data rate capabilities for downlink communications. This antenna could be suitable for CubeSat or other small satellite commercial missions, for example, Earth and planetary observations or intersatellite links.