Integration solutions for reconfigurable multi-standard wireless transceivers

Abstract

This article presents an overview of modern integration concepts for receiver, transmitter and duplexer architectures. Based on innovative design techniques, a system-in-package integrated RF transceiver architecture is proposed as a low-cost low-power alternative to traditional multi-standard transceivers. The proposed transceiver architecture unites advantages of a sub-sampling receiver with tunable low noise amplifier (LNA), a high-efficiency digital power amplifier and an integrated duplexer with on-package passive components in order to fulfill the more and more stringent requirements for wireless systems. In addition to the transceiver architecture, measurement results of building blocks are presented. A LNA circuit implemented in 65 nm CMOS technology provides a continuously tunable-gain (3-23 dB) and a tunable frequency band (4.5 GHz-5.5 GHz) with noise figure of 2 dB and IIP 3 of −6.5 dBm at the highest gain. A high Q-factor, on-package transformer, implemented in a core-less 3-metal layer system-in-package substrate, presents a coupling factor of 0.6 and a Q-factor of approximately 30. This provides a low-cost, high-performance alternative solution to integrated matching networks and duplexers. IntroductionModern wireless transceivers require multi-band and multi-standard operation, which leads to complex, bulky and power hungry implementations. An architecture for state-of-the-art multi-standard transceiver is shown in Fig. 1, where several transmitter (TX) and receiver (RX) chains are required in order to fulfill specifications for wireless standards.With the evolution of wireless systems, even more communication standards are being proposed while maintaining backward compatibility, therefore, cost and complexity of RF transceivers tend to increase. For high-performance communication standards, external off-chip components with optimized performance such as duplexer filter and power amplifier (PA), are necessary to satisfy ever-growing standard requirements. On the contrary, for low-performance battery operated applications such as Internet of things (IoT), lowpower and low-cost implementations are desired.This article presents a set of innovative design concepts, for receivers, transmitters and system-in-package (SiP) integration, which provides reconfigurability, wide frequency operation, higher power efficiency and low-cost. Based on the presented concepts, an RF transceiver architecture shown in Fig. 2 is proposed. The RX chain is based on a tunable active-balun LNA and a sub-sampling down-