A 5–6-GHz CMOS Beamforming Transceiver Front-End for Fiber-to-the-Room All-Optical Wi-Fi Solution
Lei Xin, Zhen Zhao, Yukun He, Yuyan Lv, Zhao Yuan, Yuhang Chen, Yaqi Nan, Mengyuan Guo, Haoran Yang, Zhixiong Ren, Hao Xiong, Lei Jing, Wang Xiang, Tianhai Chang, Dan Li, Li Geng, Xiaoyan Gui
Abstract
This letter presents a 5–6-GHz CMOS beamforming transceiver front-end with high linearity and low power consumption for fiber-to-the-room (FTTR) all-optical Wi-Fi solution, which can greatly reduce the transmission power and eliminate signal mutual interference among access points compared with traditional architecture, by aggregating beams of multichannel. The transmitter (TX) employs a high-linearity power amplifier, a variable-gain amplifier, a 5-bit passive attenuator (ATT), and a 4-bit passive phase shifter (PS). The receiver (RX) is composed of a single-to-differential variable gain low-noise amplifier (LNA), frequency-tuning buffers, a 5-bit ATT, and a 4-bit PS. Implemented in a 55-nm CMOS technology, the measured output power 1dB compression point (OP1dB) of TX is better than 12.1 dBm. The error vector magnitudes (EVMs) of the TX at 0-dBm output power with 80-MHz 256-quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) signal are better than −36.3 dB, and the EVMs of the RX at −40 dBm input power are better than −37.8 dB. The noise figure is 4.3 dB in high-gain mode.