Single-Board Integrated mm-Wave Full-DBF Tx Array using ME-Dipole for B5G/6G Applications

A millimeter-wave (mm-Wave) full-digital beamforming transmitting array using magnetoelectric (ME) dipole antenna is proposed in this article. The array is a single printed circuit board (PCB) with four ME-dipole antennas as radiating elements and a four-channel transmitting (Tx) chip mounted on the bottom layer. Two types of metallic vias are involved in the array to eliminate the plate modes generated in the bonding layer. The measurement results of the fabricated prototype indicate that, a maximum EIRP of 37 dBm at saturation point (Psat) and a data rate of 2.4 Gbps with 1.35% error vector magnitude (EVM) using 64-QAM waveforms is achieved by the array at 27 GHz.

I. Introduction

The millimeter-wave (mm-Wave) technology provides abundantly available spectrum resources to meet the large capacity and ultra-high transmission requirement of the beyond fifth-generation (B5G) and upcoming sixth-generation (6G) wireless communication systems [1], [2]. Generally, the mm-Wave active beamforming array can be classified into three types, i.e., analog beamforming array (ABF) [3], [4], hybrid beamforming array (HBF) [5] and full-digital beamforming array (FDBF) [6], [7]. The structure of FDBF array is shown in Fig. 1. The advantages of high beamforming precision, fast beam steering speed, flexible multi-beam ability and high precoding enable the FDBF array to be widely employed [6], [7]. Magnetoelectric (ME) dipole antennas have merits of wide bandwidth, compact and simple structure, thus, have been widely reported. In [8], [9], the ME-dipole antenna arrays are composed of different substrates that are screwed together. Generally, various compact substrate integrated mm-Wave arrays are fabricated using a low-cost standardized printed-circuit board (PCB) process with bonding films between the laminates. Due to the limitations of the processing technology, the plate modes generated in the bonding layer can lead to impedance mismatch and gain variation in the operation frequency band.