Microwave and Optical Technology Letters最新文献

Closed-loop Pole Stability Criterion and Quantitative Stability Analysis for High-Order Charge-Pump Phase-Locked Loops 高阶电荷泵锁相环的闭环极点稳定性判据及定量稳定性分析

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-16 DOI: 10.1002/mop.70835

Zengshuang Wang, Yiting Zhang, Nengxu Zhu, Zenglong Zhao, Keping Wang, Fanyi Meng

{"title":"Closed-loop Pole Stability Criterion and Quantitative Stability Analysis for High-Order Charge-Pump Phase-Locked Loops","authors":"Zengshuang Wang, Yiting Zhang, Nengxu Zhu, Zenglong Zhao, Keping Wang, Fanyi Meng","doi":"10.1002/mop.70835","DOIUrl":"https://doi.org/10.1002/mop.70835","url":null,"abstract":"<div>\u0000 \u0000 <p>Open-loop phase-margin analysis is widely used to assess the stability of phase-locked loops (PLLs). However, it characterizes only the open-loop frequency response and cannot quantitatively relate closed-loop pole locations to transient dynamics, damping, and resonant peaking, which limits quantitative stability-margin evaluation for high-order charge-pump PLLs. Based on a linear small-signal model and root-locus theory, this work derives the closed-loop pole-zero distributions of second- through fifth-order charge-pump PLLs and establishes a quantitative closed-loop pole constraint for practical stability-margin evaluation: excluding pole-zero doublets, the magnitude of the real part of every pole of the closed-loop transfer function should be greater than one-half of the loop bandwidth. Used together with conventional Bode-plot phase-margin analysis, the proposed criterion enables complementary stability verification in the open-loop frequency domain and the closed-loop complex-frequency domain. A 6 GHz fifth-order PLL frequency source using an active loop filter is evaluated through circuit simulation and three-temperature environmental testing of a 9 × 9 mm microassembled prototype. When the dominant closed-loop poles violate the proposed criterion, the PLL loses lock and drifts toward lower frequencies even though the open-loop phase margin is 45°. After the loop-filter parameters are optimized so that the relevant poles satisfy the criterion, the PLL remains stably locked over the full temperature range and achieves a measured phase noise of −109 dBc/Hz at a 100 kHz offset. The analytical, simulated, and measured results consistently validate the criterion. It is applicable to charge-pump PLLs using second- through fifth-order active or passive loop filters and provides explicit quantitative constraints for the loop-parameter design of RF frequency sources and high-speed clock circuits.</p></div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 10","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Compact Ultra-Wideband Implantable Antenna for Bovine Health Monitoring 用于牛健康监测的紧凑型超宽带植入式天线

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-15 DOI: 10.1002/mop.70830

Aketelieke Sailike, Zhiwei Song

引用次数: 0

Novel Suspension Line Sensor for Detecting Liquid Mixing Uniformity and Dielectric Property 新型液体混合均匀性和介电性能检测悬索传感器

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-15 DOI: 10.1002/mop.70832

Qunliang Wang, Yanxiong Wang, Zhao Li

引用次数: 0

A Novel Miniaturized High Gain Vivaldi Antenna With Enhanced Low-Frequency Directivity 增强低频指向性的新型小型化高增益维瓦尔第天线

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-15 DOI: 10.1002/mop.70828

Ruiyang Shen, Xiaolin Mi, Xiuli Xu, Qiping Chen, Guo-Min Yang

{"title":"A Novel Miniaturized High Gain Vivaldi Antenna With Enhanced Low-Frequency Directivity","authors":"Ruiyang Shen, Xiaolin Mi, Xiuli Xu, Qiping Chen, Guo-Min Yang","doi":"10.1002/mop.70828","DOIUrl":"https://doi.org/10.1002/mop.70828","url":null,"abstract":"<div>\u0000 \u0000 <p>This letter proposes a novel compact miniaturized Vivaldi antenna, which achieves remarkable size reduction while maintaining excellent low-frequency directional radiation performance. By optimizing the dimension and length of periodic slots on the tapered slot and adopting terminal absorbing resistors, the antenna obtains gain improvement without degrading the impedance bandwidth, offering an effective solution for UWB antenna optimization. Furthermore, a customized triangular director combined with a zero-index metamaterial composite structure is introduced. Making full use of the space at the antenna aperture, it further enhances the low-frequency directivity and improves the overall realized gain. Loading periodic slots on the tapered slot-line contributes to additional gain enhancement. The proposed antenna achieves a realized gain of 4.5–13 dBi across the entire L-band with favorable sidelobe suppression. Featuring compact footprint, high directivity, and low sidelobe level, the antenna is well-suited for radar systems that require high imaging resolution and strong anti-interference capability.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 10","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Coding Metasurface Integrated Fabry–Perot Cavity Antenna for Dual-Polarized Broadband Radar Cross Section Reduction 编码超表面集成法布里-珀罗腔天线用于双极化宽带雷达截面减小

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-15 DOI: 10.1002/mop.70829

Yufeng Liu, Jiahao Zhou, Lei Xu, Jiao Zhang

引用次数: 0

A Compact Circularly Polarized Antenna for Wireless Medical Applications 用于无线医疗应用的紧凑型圆极化天线

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-15 DOI: 10.1002/mop.70824

Jiangli Shang, Haoyi Li, Jinhang Li, Zhiqiang Zhen

{"title":"A Compact Circularly Polarized Antenna for Wireless Medical Applications","authors":"Jiangli Shang, Haoyi Li, Jinhang Li, Zhiqiang Zhen","doi":"10.1002/mop.70824","DOIUrl":"https://doi.org/10.1002/mop.70824","url":null,"abstract":"<div>\u0000 \u0000 <p>In this article, a compact broadband circularly polarized implantable antenna is produced, operating at the 2.45 GHz Industrial, Scientific, and Medical (ISM) band for wireless medical applications. A multi-layer tissue model is established as the simulation environment, where the antenna is placed at a depth of 3.5 mm beneath the skin surface, without any via holes. The antenna configuration is extremely compact, with a radiator size of only 4 × 4 mm, and the impedance bandwidth of 2.21–2.86 GHz (26.7%) is simulated. By cutting slots of different shapes to increase the current path, the miniaturization and circular polarization characteristics of the antenna are realized, and the 3 dB Axial Ratio bandwidth is 2.35–2.53 GHz (7.36%). The maximum value of the gain is −19.5 dBi at 2.45 GHz. To analyze the distance of wireless communication, the link budget is calculated at data rates of 7 Kbps, 100 Kbps, and 1 Mbps respectively. In addition, the specific absorption rate (SAR) is also calculated to ensure human safety. By setting the proposed antenna in pig skin, the measured impedance bandwidth is as wide as 15.1%, showing that the required ISM frequency band can still be covered.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"68 10","pages":""},"PeriodicalIF":1.1,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149205749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Millimeter-Wave Low-Loss and Wideband Rat-Race Coupler Implementation and Verification Using Micro-Structure Electrochemical Fabrication Process 毫米波低损耗宽带大鼠耦合器微结构电化学制造工艺的实现与验证

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-15 DOI: 10.1002/mop.70818

Jing Zhou, Yang Li, Lijie Xu, Feng Huang, Bo Li, Lei Zhu

引用次数: 0

A Miniaturized High-Gain Vivaldi Antenna Based on Irregular Curved Slots and Metasurface 基于不规则弯曲槽和超曲面的微型化高增益维瓦尔第天线

IF 1.1 4区工程技术

Microwave and Optical Technology Letters Pub Date : 2026-10-15 DOI: 10.1002/mop.70823

Jinxin Li, Yabo Li, Ruizhi Liu, Lingrun Zhu, Yilin Jiang, Zhihong Xi

引用次数: 0

Lumped CMOS Branch-Line Coupler With Tunable Harmonic Rejection for 5G UHF Applications 5G UHF应用中具有可调谐谐波抑制的集总CMOS分支线耦合器