A Wideband and Wide-Scanning Circularly Polarized Tightly Coupled Dipole Array with Low Profile for L-band Satellite Communication Applications

This paper proposes a wideband and wide-scanning circularly polarized tightly coupled dipole array (TCDA). To obtain better circular polarization performance, this array innovatively uses a multi-ridge resonance suppression structure based on the ridged waveguide, which solves the problem of introducing common-mode resonances when a dual-linear polarization is fed by concentric radiators. Additionally, a folded Marchand balun is used to provide balanced feeding for the array, and two layers of frequency-selective surfaces (FSSs) are employed to enhance impedance matching, achieving a 60 degrees scanning from 0.9GHz to 1.4GHz with voltage standing wave ratio (VSWR) below 3.75 in the operating frequency bands. Furthermore, the array has a low profile of 0.15 lambda(low), where lambda(low) represents the free space wavelength at the lowest frequency of 0.9GHz. It is beneficial for miniaturized design and has broad application prospects in satellite communication.