Indium phosphide (InP) heterojunction bipolar transistors (HBTs) with $f_{t}/f_{\max}$ of 350/675 GHz are studied and explored for a linear, high efficiency and broadband power amplifiers (PAs) at mm-wave frequencies. Unlike the conventional transmission-like-based design, this article presents a compact, broadband transformer-based power combining and impedance matching using the waveform engineering approach. We present, for the first time, mm-wave (40–60 GHz) InP topologies incorporating the following: 1) on-chip transformer for broadband, efficient and compact impedance matching and power combining; 2) synthesis of optimal second-harmonic impedance through transformer center tap to achieve high-efficiency differential PA operation; and 3) biasing techniques to reduce AM–PM distortion for linearity enhancement. This work reports a transformer-based push–pull InP PA in $0.25~\mu \text{m}$ technology across 42–62 GHz demonstrating a peak power added efficiency (PAE) of 39.5% and peak $P_{\text{sat}}$ of 20.6 dBm. The PA supports 4 GHz bandwidth at 52 GHz with an EVM of −22.9 dB and an adjacent channel leakage ratio (ACLR) of −32 dBc for an 8 Gb/s QPSK signal at 13.3 dBm average output power. This work presents one of the highest efficiency with wide bandwidth and highest linearity mm-wave PAs in integrated technology.

中文翻译：

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基于 42-62 GHz 变压器的宽带毫米波 InP PA，具有二次谐波波形工程和增强的线性度

磷化铟 (InP) 异质结双极晶体管 (HBT) $f_{t}/f_{\max}$ 研究和探索了 350/675 GHz 的线性、高效和宽带功率放大器 (PA) 的毫米波频率。与传统的基于传输的设计不同，本文介绍了一种使用波形工程方法的紧凑型、基于宽带变压器的功率组合和阻抗匹配。我们首次介绍了毫米波 (40–60 GHz) InP 拓扑结构，其中包含以下内容：1) 用于宽带、高效和紧凑的阻抗匹配和功率组合的片上变压器；2）通过变压器中心抽头合成最优二次谐波阻抗，实现高效差分PA运行；3) 偏置技术，以减少 AM-PM 失真以增强线性度。这项工作报告了一种基于变压器的推挽式 InP PA $0.25~\mu \text{m}$ 42–62 GHz 的技术展示了 39.5% 的峰值功率附加效率 (PAE) 和峰值功率附加效率 (PAE) $P_{\text{sat}}$ 20.6 dBm。对于平均输出功率为 13.3 dBm 的 8 Gb/s QPSK 信号，PA 在 52 GHz 时支持 4 GHz 带宽，EVM 为 -22.9 dB，相邻信道泄漏比 (ACLR) 为 -32 dBc。这项工作是集成技术中效率最高、带宽和线性度最高的毫米波 PA 之一。