4.3 A 43mm² Fully Integrated Legacy Cellular and 5G FR1 RF Transceiver with 24RX/3TX Supporting Inter-Band 7CA/5CA 4×4 MIMO with 1K-QAM

As mobile applications have become more prevalent, the demand for higher network capacity and data rates has increased. This has led to the development of complicated platforms including RF transceivers that can support various frequency bands, a massive multiple-input and multiple-output (MIMO), multiple carrier components (CCs) and carrier aggregations (CAs). This paper presents a fully integrated, versatile RF transceiver designed to handle high data rates and to achieve a cost-efficient RF solution, incorporating various techniques. The transceiver comprises 24 receivers (RXs) and 7 RX local oscillators (LOs) to support 9 downlink (DL) inter-band 7CA or 5CA with 4×4 MIMO, 3 transmitters (TXs) and 3 TX LOs to enable 3 uplink (UL) MIMO, 2 feedback receivers (FBRXs), a dual-band global navigation satellite system (GNSS), and a digital interface, as depicted in Fig. 4.3.1. It supports both NR (5G) and legacy (2/3/4G) protocols, operating across a very wide frequency range spanning from 450MHz to 7125MHz.