A Novel Hybrid Phased Array Antenna for Satellite Communication on-the-Move in Ku-band

Abstract

This paper introduces a novel waveguide hybrid phased array (HPA) for mobile satellite communications operating in Ku-band. The array is low profile and low cost, adopting an electrical scan in elevation and mechanical scan in azimuth to track satellites. High directivity and wide bandwidth impedance is provided by a dual linear polarized waveguide radiating element that covers both Rx and Tx frequencies within the band. The vertical and horizontal polarizations are excited by direct feeding and slot coupled aperture feeding, respectively. The array structure of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$32 \times 12$</tex-math></inline-formula> elements is split into inclined and interlaced 12 subarrays 225 mm in height. The feed networks and duplexers are designed in unconventional waveguide sizes. In the system, there are 12 independent receiving (Rx) and transmitting (Tx) modules with phased shifter components, which realize beam and polarization tracking. The system is designed to track satellites by scanning <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$15^\circ{-}75^\circ$</tex-math></inline-formula> (relative to the ground plane) electrically in the elevation and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0^\circ{-}360^\circ$</tex-math></inline-formula> mechanically in the azimuth. The array has been successfully developed and measured. The maximal gain loss in scanning range is about 4.0 dB.