A Dual-Band Polarisation-Reconfigurable Half E-Shaped Antenna Array for Q-Band Applications

This paper presents a Dual-Band (30GHz & 38GHz) Half E-shaped antenna array that provides reconfigurable circular polarisation and shared aperture capability for Q-band applications. Q-band communication is attractive due to the higher data rates and capacity at these frequencies. However, the smaller antenna size at Q-band means that intricate broadband antenna concepts (e.g. spirals) are difficult to implement. Therefore, this paper proposes a resonance antenna sub-array to provide key benefits while maintaining low complexity and low cost. The sub-array consists of four linearly polarised Half E-shaped antennas arranged in rotational symmetry of a 2x2 array configuration. Each element has been kept electronically small so that the size of a 2x2 subarray is about 0.8λ38GHz. This enables beam steering in both azimuth and elevation planes from a large phased array. Each Half E-shaped antenna provides dual-band resonance for shared aperture functionality. By feeding each antenna with a sequential +90° or -90° phase shift, the combined beam can be reconfigured to provide either RHCP or LHCP respectively. This paper provides solution for future high-performance Qband applications by realising a shared aperture array with small size, simple fabrication and low cost.