{'fraction_non_alphanumeric': 0.036488027366020526, 'fraction_numerical': 0.019384264538198404, 'mean_word_length': 4.814569536423841, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Mutual-coupling reduction of four-element cavitybacked slot antenna system using mushroom walls

In this paper, double-layer mushroom walls are applied in between the substrate integrated waveguide (SIW) cavity-backed slot (CBS) antennas for reducing inter-element mutual coupling of a four-element antenna system. The mushroom wall comprises two printed circuit boards (PCB), two arrays of metallic patches printed onto the both surfaces of the PCBs, a shared ground sandwiched in between the PCBs and an array of vias connecting the patches to the ground. A compact mushroom wall loaded four-element SIW CBS antenna array, wherein the center-to-center distance of the antenna elements is 0.42 λ (λ is the wavelength in free space at 2.4 GHz), achieves extremely high inter-element isolation of 43 dB throughout the -10 dB reflection coefficient bandwidth of 2.395- 2.433 GHz.