A Highly-Efficient Multi-Band Multi-Mode All-Digital Quadrature Transmitter

Abstract

A novel highly-efficient multi-band multi-mode all-digital quadrature transmitter is presented. In the transmitter, a switching-mode power amplifier (PA), also referred to as digital power amplifier (DPA), which consists of an in-phase PA (I-PA) and a quadrature PA (Q-PA), is controlled by the digital codewords based on an input signal to turn on and off the power cells inside the I-PA or the Q-PA. Due to the load interaction between the I-PA and the Q-PA, a 2-dimensional (2-D) digital pre-distortion (DPD) is applied to linearize the DPA. The whole transmitter is implemented in 40 nm CMOS LP process and occupies a die area of 0.7 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm mm}^{2}$</tex></formula> . The all-digital quadrature transmitter can support 20 MHz, 40 MHz, and 80 MHz WiFi signals, Band 38 and Band 40 LTE signals with class 3 output power, and Bluetooth BDR, EDR2, and EDR3 signals.