A 28-GHz CMOS Phased-Array Beamformer Utilizing Neutralized Bi-Directional Technique Supporting Dual-Polarized MIMO for 5G NR

Abstract

This article presents a low-cost and area-efficient 28-GHz CMOS phased-array beamformer chip for 5G millimeter-wave dual-polarized multiple-in-multiple-out (MIMO) (DP-MIMO) systems. A neutralized bi-directional technique is introduced in this work to reduce the chip area significantly. With the proposed technique, completely the same circuit chain is shared between the transmitter and receiver. To further minimize the area, an active bi-directional vector-summing phase shifter is also introduced. Area-efficient and high-resolution active phase shifting could be realized in both TX and RX modes. In measurement, the achieved saturated output power for the TX-mode beamformer is 15.1 dBm. The RX-mode noise figure is 4.2 dB at 28 GHz. To evaluate the over-the-air performance, 16 H+16 V sub-array modules are implemented in this work. Each of the sub-array modules consists of four 4 H+4 V chips. Two subarray modules in this work are capable of scanning the beam from −50 • to +50 •. A saturated EIRP of 45.6 dBm is realized by 32 TX-mode beamformers. Within 1-m distance, a maximum SC-mode data rate of 15 Gb/s and the 5G new radio downlink packets transmission in 256-QAM could be supported by the module. A 2 × 2 DP-MIMO communication is also demonstrated with two 5G new radio 64-QAM uplink streams. Thanks to

A CMOS Dual-Polarized Phased-Array Beamformer Utilizing Cross-Polarization Leakage Cancellation for 5G MIMO Systems

“…5 shows the block diagram of the proposed 28-GHz beamformer chip. Area-efficient neutralized bi-directional architecture is employed to share the same signal chain between the TX and RX [6]. Totally eight element-beamformers (4H + 4V) are integrated to support the DP-MIMO.…”

“…In this work, the element-beamformer is designed based on the neutralized bi-directional architecture for saving chip area and manufacturing cost [6]. The occupied on-chip area for each beamformer is reduced to half by the bi-directional technique.…”

“…In recent years, special attention have been focused on realizing low-cost and power-efficient 5G millimeter-wave DP-MIMO systems [6]- [11], [19]. Pang et al [6] introduce an eight-element beamformer chip for 5G single-user DP-MIMO communications. The area-efficient bi-directional technique is utilized for minimizing the manufacturing cost.…”

Programmable Active Mirror: A Scalable Decentralized Router

“…On the circuit side, there has been a push to higher frequencies (where more bandwidth is available) by improving critical circuit building block performance, e.g., power amplifier efficiency and linearity or receiver sensitivity. On the system level, we have moved from single-channel static transmitters and receivers to sophisticated programmable massive multiple-input multipleoutput (MIMO) systems that can form larger apertures in transmitters and/or receivers to perform a slew of complex functions [1]- [3]. These arrays enhance the effective isotropic radiated power (EIRP) in transmitters and sensitivity of receivers to increase the available data rates through the second key parameter in Shannon's theorem, i.e., SNR.…”

“…andR r x by varying r m 3. As an example of the effect of branch position, r m , on peripheral vision, the maximum transmitted power over allR t x as a function ofR r x is shown inFig.…”