A Ku/K band dual linearly polarized Reflectarray for earth exploration satellite services

Abstract

ABSTRACT A novel single-layer dual-band, dual-polarised reflectarray was designed, developed, and tested in this paper. This Reflectarray is a vital component to use, in Earth exploration sensor systems and remote sensing satellites for measuring water levels and cryosphere research. The proposed antenna is employed in dual frequency bands from 12.5–16 GHz to 23.5–26 GHz covering Ku/K bands. The corrugated semi-circular rings enclosed with quad delay line structures attached to the outer ring constitute the Ku band unit cell with periodicity (0.55 λ 0 ) resonating at 14.5 GHz. The K band unit cell with periodicity (0.78 λ 0 ) is constructed similarly to the Ku band unit cell but with a horizontal slot that provides vertical polarisation and resonates at 24.5 GHz. This integrated unit cell configuration results in dual linear, reduced cross-polarisation and allows independent phase optimisation at each frequency band. Phase variation of 770° and 811° at the operating frequencies of 14.5 GHz and 24.5 GHz is achieved by varying the element sizes. A centre-fed RA constructed on a square aperture (12.34 λ 0 ) comprising 23 × 23 elements for each frequency band gives the measured results of 1 dB bandwidth of 24% and 10.2% and peak gain of 28.2 dB and 27.6 dB at Ku/K bands, respectively.