Performance Analysis of Low-Cost Printed Antenna Array Elements for 5G LOS-MIMO Arrays at 60 GHz

Design of 5G and beyond 5G telecommunication systems relies on utilization of diverse solutions for different envisioned applications and different constituents of an entire system. One of the research directions is the utilization of a global unlicensed millimeter wave frequency band from 57 to 66 GHz for the high throughput data transfer. Apart from the wide spectrum availability at 60 GHz, there are many problems to be resolved before the concept can become fully functional; one of the requirements is the design of low-cost, energy efficient, wideband antennas with enhanced gain, capable of overcoming propagation losses at 60 GHz. We investigate the benefits and shortcomings of four types of low-cost, printed antennas as the constituents of sub-array elements for the large line-of-sight MIMO arrays. The results are put into perspective by comparison with the most used low-cost microstrip patch sub-array element. The state-of-the-art method-of-moments computations were employed in the highly accurate analyses of the four compared antenna array elements. Although the gains of such sub-arrays can be boosted by the increases in antenna numbers, this does not hold for the efficiency or bandwidth of operation; therefore, radiation patterns and characteristics at the level of individual antennas cannot be ignored as these translate directly into the behavior of an array. Careful choice of antenna type and initial efforts in the sub-array design should be seen as a necessary first step in the design of a large line-of-sight MIMO array of superior characteristics. Graphic Abstract