Multilayer Base Station Antenna at 3.5 GHz for Future 5G Indoor Systems

The demand of wide range and high-accurate antennas for indoor fifth-generation (5G) positioning systems is highly required due to the higher frequencies and multipath components effects whereas indoor applications will suffer from the short-range coverage and the loss of signals inside the buildings. In this paper, a wide range, compact and multi-layer sub-6 GHz antenna design that can cover 3.4-3.65 GHz is proposed for fifth-generation (5G) new radio N78/N77 application. Three layers form the antenna structure whereas a full ground plane is placed at the middle layer. Furthermore, the bandwidth and resonant frequency vary by using different via radius which is placed between partial and full ground planes. The simulated results show that the proposed antenna has a return loss of less than -32 dB as well as a bandwidth of 250 MHz with a good impedance matching by 60% enlargement compared with the conventional antenna. The maximum achieved gain is 5.58 dBi at 3.5 GHz. Moreover, the proposed antenna radiates directionally with 95% and 65% as maximum radiation and total efficiency, respectively. It can radiate with wide-beam width of 79.9 and 242.4 degrees in xz and xy planes, respectively with respect to 3 dB angular.