A Compact Reconfigurable 24-29.5/38-43.5GHz Phased Array Transceiver Front-End with Self-Interference Rejection and Wideband IF Supporting TDD/FDD Operation

The ever-increasing demand for high-data rate, low-latency and increased connectivity urges the 5G new radio (NR) to support mm-Wave bands ranging from 24.25 to 43.5 GHz. However, until now the reported wideband phased-array transceivers that can fully cover both 28 GHz bands (24.25 to 29.5 GHz or Low Band, LB) and 39 GHz bands (37-43.5 GHz or High Band, HB) are limited. To cover these two frequency bands, an effective solution is to integrate 28 GHz LB and 39 GHz HB transceivers in a single chip and to use separated 28 and 39 GHz antenna arrays for LB and HB operation [1]. Although such transceiver solution has double number of antennas compared with the ultra-wideband transceiver solution, it can relax the antenna bandwidth requirements. Moreover, in a typical FDD communication system, the separated narrowband antennas can significantly reduce the self-interference (SI) from TX to RX [2] by increasing the physical spacing between the LB and HB antenna arrays, and the lossy on-chip diplexers can be avoided. However, such phased array system has increased chip size and complexity issue, the former caused by the coexisting LB and HB transceivers and the latter caused by the wideband local oscillator (LO) when considering the frequency conversion function. To address above issues, this paper presents an area-efficient phased-array transceiver front-end with wideband intermediate-frequency (IF) performance in a 65-nm CMOS process, which can support 24-29.5 and 38-43.5GHz. Meanwhile, it can be reconfigured to four operating modes, i.e. LB TDD mode, HB TDD mode, LB-TX & HB-RX FDD mode, and HB-RX & LB-TX FDD mode, respectively.