JSSC 2015第5期RF & Wireless40 nm

A Fully Integrated Transformer-Coupled Power Detector With 5 GHz RF PA for WLAN

本文介绍了一种全集成功率检测器，用于监测5 GHz RF PA的输出功率，具有高精度和宽动态范围。

±0.5 dB精度，32.5 dB动态范围，VSWR 2.8:1

功率检测器RF PAWLANCMOS变压器耦合

▸创新点1：全集成变压器耦合功率检测器（方法创新）。该设计将功率检测器完全集成在RF PA输出变压器内部，实现了零面积开销，显著降低了成本，同时提高了系统集成度。

▸创新点2：同时监测RF电流和电压（电路创新）。通过变压器次级绕组测量RF电流，并通过电容分压器测量RF电压，实现了对输出功率的精确连续监测，最大误差仅为±0.5 dB，动态范围达32.5 dB。

▸创新点3：天线阻抗失配校正能力（系统创新）。在电压驻波比（VSWR）高达2.8:1的阻抗失配情况下，仍能保持±1 dB的测量精度，支持自动天线失配校正系统，防止RF PA性能下降。

▸创新点4：高动态范围与低误差设计（性能创新）。该功率检测器在宽动态范围（32.5 dB）内实现了高精度（±0.5 dB），适用于高要求的WLAN 802.11ac通信标准。

Abstract

This paper introduces a fully integrated direct power detector that monitors both RF current and RF voltage to detect the RF output power of the on-chip RF PA realized in a standard 40 nm CMOS process. The RF current measurement is realized by as e n s ew i n d i n gi nt h eo u t p u tt ransformer, while the RF voltage waveform measurement is performed by capacitive division of the RF output voltage. Since the RF current and the RF voltage are both acquired, this power detector accurately and co