Isolation enhancement between two closely spaced substrate integrated cavity-backed slot antennas using mushroom

This paper presented a single mushroom-liking loading to enhance the isolation between two closely packed substrate integrated waveguide cavity-backed slot (SICBS) antennas. The mushroom inserted between two SICBS antennas blocks and concentrates part of the spaced-fields radiation from one antenna element, so that an inter-between isolation enhancement is achieved. The two-element parallel directed SICBS antennas (side-to-side) with the mushroom structure, wherein the height of mushroom is 0.04 λ₀ (λ₀ is the free-space wavelength at the central operating frequency), enhances the inter-between isolation by 8 dB over the operating band (|S₁₁|<;-10 dB) of 2.375 GHz-2.415 GHz.