A 2x2 Broadband Dual-Polarized Antenna Array using AiP Techniques for 5G mmWave Beamforming Systems

Abstract

This paper discusses a 2x2 broadband dual-polarized antenna array on the 4+2+4 cost-effective multilayer organic substrates with size of 13 x 13 x 0.87 mm3. Each antenna element consists of one driven patch, one stacked patch, and four parasitic elements. This work focuses on simulating and analyzing the effect of stacking ratio of driven patch and stacked patch on operating bandwidth, and adding parasitic elements to expand the bandwidth, which achieves broadband performance on a thin and cost-effective substrate. In a single antenna element, the simulated return loss of over 10dB is achieved a frequency range from 24.60 to 29.65 GHz and the realized antenna gain is more than 5.5dBi. After that, a 2x2 antenna array is designed, which each antenna element has dual feeding ports to implement dual-polarization features. In the 24.65 to 29.65 GHz range, the simulated realized gain of array in vertical polarization and horizontal polarization is from 10.7 to 12.4 dBi. The isolation levels of port-to-port and cross-polarization are better than 18dB and 14dB in the band, respectively. Finally, the 3D beam steering is simulated in four quadrants at 27GHz, and a maximum realized gain of 11.1dBi is achieved in the beam direction (θ=28°, Φ=312°) of quadrant IV. It shows that the beamforming can work properly by controlling the phase of signal in each antenna element. The cost-effective antenna structure provides a broadband benefit to cover all the 28GHz mmWave bands of 3GPP standard (n257, n258, and n261).