New Approach to Suppress Mutual Coupling Between Longitudinal-Slotted Arrays Based on SIW Antenna Loaded with Metal-Fences Working on VHF/UHF Frequency-Bands: Study, Investigation, and Principle

In this work it is demonstrated that substrate integrated waveguide longitudinal slotted array antenna (SIWLSAA) which is loaded with metal fences exhibits highisolation across VHF/UHF bands. A reference SIWLSAA used for comparison purpose comprises of 3×6 slotted arrays constructed on the top and bottom sides of the FR-4 lossy substrate has maximum isolation of -63 dB between its radiation slots. Improvement in isolation is demonstrated using a simple new technique based on inserting a metal fence between each row of slot arrays. The resulting isolation is shown to be is better than -83 dB across 200 MHz to 1.0 GHz with gain greater than 1.5 dBi, and side-lobe level less than - 40 dB. The proposed SIWLSAA is compact and has dimensions of 40×10×5 mm3 (0.026λ ₀ ×0.006λ ₀ ×0.002λ ₀ ) where λo is 200 MHz. The proposed structure should find application in multiple-input multiple-output (MIMO) and radar systems.