This paper proposes a simple novel technique for self-isolating a MIMO antenna for mmwave applications. MIMO antenna elements with inter-element separation of 0.2 mm (0.023λ at 35 GHz) and measured high isolation (> 50 dB) are presented. By observing the concentration of surface waves on the radiating patch, several rigorously optimized slots of different shapes, positions, and dimensions are etched on the patch to enhance the inter-element isolation and increase the bandwidth within 28-37.5 GHz. The circuit models of the reference and proposed antennas have been presented. The coupling is measured by the level of the differences in the output voltage in both antennas. The novel mm-wave antenna exhibits high impedance bandwidth (> 29%), high isolation (> 50 dB), high efficiency (> 90%), and low envelope correlation coefficient (<0.005). Two configurations of MIMO antenna (i.e, 1×2 and 1×4) are fabricated and measured to validate the simulation outcomes. The single reference antenna has dimensions of 10x12 mm 2 while the 1x2 array has dimensions of 19x12 mm 2 . The presented design is the first to exhibit such wideband isolation improvement without any external decoupling structure at the mm-wave frequency range, to the best of the authors' knowledge.INDEX TERMS Self-isolated antenna, mm-waves, multiple-input-multiple-output (MIMO), 5G Antennas, Patch Antenna, Surface Waves, Mutual Coupling.
Fifth‐generation millimeter‐wave devices with multiple antennas require minimal mutual interference for better overall performance. This article presents a simple but novel technique to improve the isolation between closely packed slot antenna arrays. A printed ridge gap waveguide (PRGW) structure is used to realize a low loss millimeter‐wave array's feeding mechanism. By optimally introducing a defective upper plate within the PRGW structure, the measured port isolation of the antenna elements is improved by 17 dB at 61.3 GHz. The antenna array is impedance matched to the feeding PRGW structure over a wide frequency range of 54–67 GHz. Moreover, the radiation patterns are consistent showing broadside radiation before and after introducing the defect in the PRGW structure. The fabricated prototype of the PRGW fed slot antenna array validated the predicted isolation and return‐loss bandwidths of the proposed radiating system.
A low-cost innovative MIMO antenna configuration with minimal separation between the radiating elements and high isolation over a wide frequency band is presented. Several precisely designed slots with various forms, locations, and sizes are etched on the radiating patches to improve interelement isolation throughout the mm-wave band of 30-41 GHz impedance bandwidth. This achieved elements isolation better than 70 dB with an inter-element spacing of 0.2 mm (0.02λ at 30 GHz). The suggested self-isolation method is validated by designing a 1x2 MIMO array configuration. The innovative mm-wave antenna has the following characteristics over the desired bandwidth: high impedance bandwidth ( 30%) and low mutual coupling ( 70 dB). To the authors' knowledge, the present design is the first to demonstrate such broadband isolation enhancement in the mm-wave frequency range without any sophisticated decoupling structure such as metamaterial or frequency-selective surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.