Design Fabrication and Analysis of MIMO Microstrip Patch Antennas at Millimeter Wave Band for 5G Wireless Services Submitted in partial fulfillment of the requirements

Abstract

In this work, two-port and four-port MIMO antennas are presented, working in the newlinefrequency range of 26.5 29.7 GHz with high isolation characteristics. The two and four newlineports MIMO antennas consist of identical patch elements placed orthogonal to each newlineother. The overall size of the proposed two-port MIMO antenna is 20 × 42 × 1.6 mm3. newlineThe overall size of the proposed four-port MIMO antenna is 60 × 42 × 1.6 mm3. In the newlineground plane of four-port MIMO antenna, a H-shaped slot is inserted to create the newlinebarrier for surface current between antenna elements. Bandwidth of antenna elements newlineis enhanced by inserting circular slots in the radiating patch. A quarter wave transformer newlineline is introduced in the feed line to improve impedance matching. The proposed design newlineis fabricated on a Roger (RT5880) substrate. The isolation greater than 50 dB and newlineenvelope correlation coefficient (ECC) of 0.0001 are obtained. The antenna gain varies newlinein the range of 7 8 dBi in the whole operating frequency band. Radiation efficiency, newlinegreater than 85% is achieved throughout the operating frequency band of antenna newlinedesign. In high-speed 5G wireless services where size, speed, performance, ease of newlineinstallation are main constraints, low profile antenna is very much required. To meet newlinethis requirements, MIMO microstrip patch antennas are preferred. MIMO Microstrip newlinepatch antenna has disadvantage of high mutual coupling between radiating elements. newlineThis disadvantage can however be overcome with decoupling network incorporated newlinebetween antenna elements. But the design complexity is also increased by inserting the newlinedecoupling network between the MIMO antenna elements. So, a new technique of newlineplacing the patch antenna elements in orthogonal configuration to reduce the mutual newlinecoupling between MIMO antenna elements has been introduced in this work. newlineThe millimetres wave bands are potential frequency bands for 5G cellular systems newlinebecause significant spectrum exists at this frequency band.