{"title":"Substrate Integrated Waveguide Filtering Rat-Race Coupler Using Dual-Mode Composite Cavity","authors":"Jianxing Zhuang;Jun Huang;Fang Zhu","doi":"10.1109/LMWT.2025.3561729","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3561729","url":null,"abstract":"This letter presents a compact substrate integrated waveguide (SIW) filtering rat-race coupler based on a dual-mode composite cavity (DMCC) and stacked SIW cavities (SIWCs). The dual-mode characteristics of the DMCC are systematically analyzed to guide the circuit realization. By incorporating two coupling windows between the DMCC and stacked SIWCs, the internal couplings for the TE<sub>101</sub> and folded TE<sub>101</sub> (FTE<sub>101</sub>) modes can be independently controlled, significantly reducing the design complexity of the SIW filtering rat-race coupler. To validate the design, a second-order SIW filtering rat-race coupler is designed, fabricated, and measured. The measured results agree well with the simulated ones.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 7","pages":"1001-1004"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144581544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Agile Additively Manufactured 5G/mm-Wave RF Front-End With Multilayer Conformality and Printed RF VIAs for Ultrawideband and Miniaturized Systems","authors":"Hani Al Jamal;Manos M. Tentzeris","doi":"10.1109/LMWT.2025.3558479","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3558479","url":null,"abstract":"This article presents the first fully additively manufactured (AM) multilayered RF front-end (RF-FE) for mm-wave frequencies (20–30 GHz), integrating active devices, passive printed structures, and RF signals routed on both outer layers. The system features flexible inkjet- and screen-printed RF vertical interconnects (VIAs) with insertion loss between 0.58 and 1.64 dB and minimal bending-induced degradation. Its multilayer architecture enables significant miniaturization, ideal for compact, low-cost, and sustainable mm-wave modules in wearable devices, autonomous UAVs, and smart cities. The design achieves inkjet-printed feature sizes down to <inline-formula> <tex-math>$60,mu $ </tex-math></inline-formula>m, critical for mm-wave filters, and incorporates a monopole antenna array with up to 9-dBi gain, demonstrating robust planar and conformal performance. Leveraging AM, this work establishes a pathway for miniaturized, flexible, and cost-effective RF systems, addressing key challenges in advanced communication and sensing applications.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"808-811"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Transmission Line-Based Notch Structure With a Wide Range of Variation Notch Bandwidth","authors":"Song-Zhao Zhou;Zhi-Yuan Zong;Wen Wu;Da-Gang Fang","doi":"10.1109/LMWT.2025.3560659","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3560659","url":null,"abstract":"In this letter, a novel method is proposed to realize a wide range of variation notch bandwidth in a notch structure by changing the height of the mushroom-like resonator that is embedded in the dielectric layer of the transmission line (TL). The resonator consists of narrow strips and rectangular patches and is connected to the ground through metal vias, and a detailed analysis of its working mechanism and key parameters is provided based on the equivalent circuit. The <italic>Q</i> value of the resonant circuit shows that the notch bandwidth is relevant to the equivalent capacitance ratio, which explains that the notch bandwidth can be flexibly adjusted by adjusting the height of the resonator. Its applicability to other TLs is also discussed. Furthermore, the notch structure can be applied to various antennas without affecting their radiation characteristics. Three validation structures are fabricated: narrowband and broadband notched microstrip lines, and a dual-band notched antenna with low cross-polarization, all the measured results show effects consistent with simulation predictions.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 7","pages":"981-984"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144581550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wentao Zhong;Ang Hu;Jingsong Cui;Qin Hu;Dongsheng Liu;Xuecheng Zou
{"title":"A 11-pA/Hz 5-Gb/s Inductorless Optical Receiver for High-Density Parallel Interface Application","authors":"Wentao Zhong;Ang Hu;Jingsong Cui;Qin Hu;Dongsheng Liu;Xuecheng Zou","doi":"10.1109/LMWT.2025.3553931","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3553931","url":null,"abstract":"This letter presents a 5-Gb/s inductorless optical receiver (ORX) used for high-density parallel interface application. In order to reduce the active area of single channel and mitigate the magnetic coupling effect, the on-chip inductor is limit-used. By adopting a regulated cascode (RGC) transimpedance amplifier (TIA) and an on-chip low dropout (LDO) regulator, the high-frequency noise and off-chip noise are reduced. A limiting amplifier (LA) utilizing the second-order amplifier cells with active feedback is employed, which can perform peaking characteristics at high frequencies and increase the gain-bandwidth (GBW) product. Implemented in 0.18-<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m CMOS process, the ORX achieves a measured transimpedance gain of 74 dB <inline-formula> <tex-math>$Omega $ </tex-math></inline-formula>, a −3-dB bandwidth of 3.65 GHz, and an average input-referred current noise density of 11 pA/<inline-formula> <tex-math>$sqrt {mathrm {Hz}} $ </tex-math></inline-formula>. The total area occupied by the ORX is 2.686 mm<sup>2</sup>, with a power consumption of 112.9 mW.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 7","pages":"1085-1088"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144581554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A 203-to-250GHz Staggered-Tuning Amplifier in 0.13-μm SiGe Technology","authors":"Xin Zhang;Zhiheng Liu;Fanyi Meng","doi":"10.1109/LMWT.2025.3560671","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3560671","url":null,"abstract":"An ultra-wideband four-stage 220GHz amplifier in a 0.13-<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m SiGe BiCMOS technology is proposed in this letter. The cascode topology is deployed as a unit amplifier to provide sufficient power gain. To broaden the bandwidth, the staggered-tuning model for the cascode amplifier is studied, analyzed, and applied in the amplifier design. The fabricated circuit achieves a peak gain of 15.5 dB at 210GHz, a 3-dB bandwidth of 47GHz, an output <inline-formula> <tex-math>$P_{text {1 dB}}$ </tex-math></inline-formula> of −9.7 dBm at 220GHz. The amplifier occupies a compact area of 0.154 mm<sup>2</sup>. The dc power consumption is 20.4mW at 2.4 V supply voltage.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 7","pages":"1049-1052"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144581725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cognitive Broyden-Based Input Space Mapping for Design Optimization","authors":"José E. Rayas-Sánchez","doi":"10.1109/LMWT.2025.3560909","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3560909","url":null,"abstract":"Cognition-driven design of RF and microwave circuits is an emerging and promising approach to efficient design optimization of computationally expensive fine models. Existing techniques for cognition-driven design have been developed for optimizing microwave filters without exploiting traditional coarse model representations, e.g., equivalent circuits. Instead, intermediate feature-space parameters have been used to establish other types of mappings in the design process. In this letter, a cognitive space mapping (SM) technique that fully exploits traditional coarse models is proposed for the first time. The proposed cognitive SM approach exploits a previous cognition-driven parameter extraction (PE) formulation at each SM iteration. This cognitive SM technique follows an algorithmic structure that is an extension of that one used by the Broyden-based input SM, better known as aggressive SM (ASM). A synthetic benchmark example illustrates the performance improvement of the proposed cognitive SM versus ASM.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"760-763"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Byeongcheol Yoon;Sooji Bae;Seungju Lee;Sungwoon Hwang;Jooyoung Jeon;Junghyun Kim
{"title":"A Broadband Doherty-Like Load-Modulated Balanced Amplifier With an Optimized Impedance Transformation Ratio in InGaP/GaAs HBT Process for Handset Applications","authors":"Byeongcheol Yoon;Sooji Bae;Seungju Lee;Sungwoon Hwang;Jooyoung Jeon;Junghyun Kim","doi":"10.1109/LMWT.2025.3560289","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3560289","url":null,"abstract":"This letter presents a design methodology for implementing broadband load-modulated balanced amplifier (LMBA) for handset applications. It is evaluated which architecture, Doherty-like LMBA (DL-LMBA) or pseudo-Doherty LMBA (PD-LMBA), is more suitable for InGaP/GaAs HBT power amplifier (PA). The impedance transformation ratio (ITR) is optimized through an analysis of correlation between the coupler impedance (<inline-formula> <tex-math>$Z_{0}$ </tex-math></inline-formula>) and matching network (MN). A prototype LMBA attains measured saturation power (<inline-formula> <tex-math>$P_{text {SAT}}$ </tex-math></inline-formula>), collector efficiency (CE), and 6-dB output power back-off (OBO) CE of over 33.2 dBm, 45.2%, and 42.0%, respectively, in the range of 3.2–5.0 GHz. The LMBA is also evaluated by 5G NR FR1 100-MHz QPSK CP-OFDM with 9.5-dB peak-to-average power ratio (PAPR), achieving 26.6-dBm average output power (<inline-formula> <tex-math>$P_{text {avg}}$ </tex-math></inline-formula>) with 37.7% average CE (CE<sub>avg</sub>) at an adjacent channel leakage ratio (ACLR) of −33 dBc.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"848-851"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A 232–282 GHz Frequency Quadrupler in 130-nm SiGe HBT SG13G3Cu Technology","authors":"Boli Peng;Michael Schröter","doi":"10.1109/LMWT.2025.3557327","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3557327","url":null,"abstract":"A 232–282 frequency quadrupler has been designed and fabricated using Leibniz Institute for High Performance Microelectronics (IHP’s) highest performance 130-nm SiGe BiCMOS technology, featuring <inline-formula> <tex-math>$f_{T}$ </tex-math></inline-formula>/<inline-formula> <tex-math>$f_{text {MAX}}$ </tex-math></inline-formula> values of 470/650 GHz. It consists of stacked Gilbert-cell (GC) doublers, with neutralization capacitances in the transconductance pair to enhance conversion gain (CG), and a miniaturized balun structure for the low frequency differential input signal generation. The frequency quadrupler achieves a peak output power of –4.5dBm, corresponding to a 3.5 dB CG at 236 GHz, with a 0.56% dc-to-RF efficiency and a 3 dB bandwidth of 50 GHz ranging from 232 to 282 GHz. This performance is realized with a dc power consumption of only 63 mW and a chip area of 0.49 mm<sup>2</sup>.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 7","pages":"1045-1048"},"PeriodicalIF":0.0,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144581517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A 196-to-254-GHz Slot-Array Coupled Detector Using Process-Invariant Pseudo Resistor Technique","authors":"Qingfan Zeng;Yiming Yu;Jiacheng Ding;Peilin Lv;Huihua Liu;Yunqiu Wu;Cheng Wang;Qingsong Bai;Shang Ma;Jianhao Hu;Kai Kang","doi":"10.1109/LMWT.2025.3558285","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3558285","url":null,"abstract":"This letter presents a compact slot-array coupled terahertz (THz) detector achieving a high baseband responsivity of 10 MV/W. The core circuit of the THz detector is based on the principle of square-law detection and realized by a common-source structure. In order to reduce the impact of process variation, a novel bias scheme for pseudo resistor (PR) is proposed to stabilize the baseband bandwidth. A slot-array coupler is employed to extract the THz signal from waveguide for measurement requirement. Fabricated in a 65-nm CMOS process, the proposed detector demonstrates effective detection from 196 to 254 GHz with 25.8% fractional bandwidth. The measured responsivity and noise equivalent power (NEP) are 1.6 kV/W and 39 pW/Hz<sup>0.5</sup>, respectively. Together with the cascaded baseband amplifier, the maximum baseband responsivity of 10 MV/W is achieved.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 7","pages":"1057-1060"},"PeriodicalIF":0.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144581553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"RF-Input Doherty-Like Load-Modulated Balanced Amplifier With Decade Bandwidth Enabled by Novel Broadband 180° Power Divider","authors":"Pingzhu Gong;Niteesh Bharadwaj Vangipurapu;Jiachen Guo;Kenle Chen","doi":"10.1109/LMWT.2025.3559761","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3559761","url":null,"abstract":"This letter presents the first demonstration of a decade-bandwidth Doherty-like load-modulated balanced amplifier (DL-LMBA). Leveraging the recently developed signal-flow-based broadband LMBA theory, a frequency-agnostic phase-alignment condition is identified that is critical for ensuring intrinsically broadband load modulation (LM) behavior for DL-LMBA, thereby overcoming longstanding bandwidth limitations in DL-LMBA design. In addition, a reflective-type-phase-shifter-based 180° power divider is proposed for the wideband operation of DL-LMBA. To prove the proposed concept, an ultrawideband RF-input DL-LMBA is developed using GaN technology covering the frequency range from 0.2 to 2 GHz. Experimental results demonstrate an efficiency of 44%–67% for peak output power and 43%–75% for 6 dB output back-off (OBO), respectively.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"860-863"},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}