An Inverse-Designed Passively Coupled N-Path Filter with gm-Boosted Active HBT Switches

📋 论文概要

本文提出了一种基于逆向设计的被动耦合N-path滤波器，采用gm增强型HBT开关和非谐振无源网络，以提升动态范围和可调性。通过混合实-二进制逆向设计算法自动插入可变尺寸MIM电容，实现了紧凑的多层低GHz无源结构，覆盖0.8-2.6GHz频率范围。

💡 主要创新点

• 提出混合实-二进制逆向设计算法，能自动在布局中插入可变尺寸MIM电容，实现紧凑多层无源网络。
• 采用gm增强型HBT开关替代传统CMOS开关，改善无源耦合N-path滤波器的动态范围和噪声性能。
• 通过非谐振无源网络耦合实现高阶滤波，无需谐振元件，增强调谐范围。

🏷 关键词

📄 原文摘要

Abstract A 0.8-to-2.6GHz N-path filter with gm-boosted HBT switches and inverse-designed nonresonant passive networks is presented to enhance dynamic range and tunability of passively coupled higher-order N-path filters. A hybrid real-binary inverse design algorithm capable of inserting variable-size MIM capacitors in layouts enables synthesis of compact multilayered low-GHz passives. A BiCMOS filter prototype achieves >15dBm P1dB, <5dB noise figure and <4dB insertion loss across the full tuning range. N-path filters with multiphase, periodically switched filter kernels have gained attention over the past 2 decades for enabling high-Q, frequency-tunable responses not achievable with traditional on-chip passives. Their performance tradeoffs are governed by the CMOS switch RONCOFF product [1-2]. Larger switches improve linearity and out-of-band (OOB) rejection but increase parasitics, raising CV²f power and unwanted charge sharing that elevates noise

👥 作者与机构

Vinay Chenna, Hossein Hashemi

University of Southern California, Los Angeles, CA