A Compact Base Station Antenna Array With High Isolation in New U6G Frequency Band

The 3GPP RAN Plenary has started the standardization of frequency band 6425–7125 MHz(U6G) as a new IMT licensed frequency band[1] and International Telecommunication Union(ITU) will be carried forward in the final acts of World Radiocommunication Conference 2023(WRC-23)[2]. In this paper, a compact 3×4 base station antenna array with high isolation and improved radiation patterns operating in 6.425-7.125GHz frequency band is proposed. The proposed array consists of twelve miniature dual-polarized antenna elements, which are designed for pressure casting of mass manufacturing. The horizontal spacing between 1×3 subarrays is 0.36λ(λ is the wavelength of the electromagnetic wave at 6.775GHz in the free space) and the vertical spacing between the antenna in the same subarray is 0.65λ. High isolation of above 20dB is achieved successfully by deploying a partial reflective decoupling layer (PRDL) and special metal strips in the array. Kinds of electromagnetic couplings in the array are effectively decreased by the two decoupling methods and improved radiation patterns are obtained. The simulated results show that the compact array with high isolation and improved radiation patterns becomes the candidate of the base station antenna array operating in the brand new 6.425-7.125GHz frequency band.