Di Cui;Junwei Wang;Bin Yao;Qinhong Zheng;Tai Xiang;Runeng Zhong
{"title":"Morphable Liquid-Metal Concentrators to Improve Microwave Heating Efficiency","authors":"Di Cui;Junwei Wang;Bin Yao;Qinhong Zheng;Tai Xiang;Runeng Zhong","doi":"10.1109/LMWT.2025.3582947","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3582947","url":null,"abstract":"In this work, two morphable liquid-metal concentrators, the shell and flower, were proposed to improve the heating efficiency in the microwave reaction cavity. The concentrators, containing Gaussian and static cells, would inflate when additional liquid metal was pumped into the Gaussian cells, reflecting more microwaves to the heated sample, and improving the heating efficiency. To demonstrate the heating efficiency, two multiphysics heating models set with the shell and flower concentrators were designed. To validate the simulation results, an experimental system was built, and the corresponding experiments were carried out. The agreement of the simulation and experiment results validated and provided a novel route for designing the concentrators to improve microwave heating efficiency.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 10","pages":"1650-1653"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145242576","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":"Continuously Tunable Ku-Band GaAs Bandstop Filter With Reconfigurable All-Pass Capabilities","authors":"Andrés Fontana;Dimitra Psychogiou","doi":"10.1109/LMWT.2025.3580893","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3580893","url":null,"abstract":"A multiconfigurable monolithic microwave integrated circuit (MMIC) filter is reported. It exhibits three modes of operation, namely, a high-attenuation single-notch bandstop (BS) mode, a dual-notch BS mode, and an all-pass (AP) mode. It is based on a bridged-T network (BTN) using a minimum number of lumped elements and a signal cancellation technique to counteract the effect of the low on-chip quality factor. Transfer function tuning and bandstop-to-all-pass filter (BSF-to-AP) mode reconfigurability are readily obtained by tuning the frequency of two resonators. A prototype was manufactured using a pHEMT GaAs MMIC process exhibiting a BS mode with frequency tuning range (<inline-formula> <tex-math>$Delta f_{0}$ </tex-math></inline-formula>) of 16% and suppression up to 68.5 dB, a dual-notch BS mode with <inline-formula> <tex-math>$Delta f_{0}$ </tex-math></inline-formula> of 15% and 20% fractional bandwidth (FBW), and an AP mode with insertion loss <5.3 dB.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1284-1287"},"PeriodicalIF":3.4,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11052270","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"RF Integrated Passive Devices Trimming Using Phase Change Material Switches","authors":"Kariny Nunes Maia;Audrey Martin;Pierre Blondy","doi":"10.1109/LMWT.2025.3581156","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3581156","url":null,"abstract":"This letter presents a phase-change material (PCM) switch-based trimming technique for an radio frequency (RF) <italic>L</i>–<italic>C</i> output matching circuit fabricated on high-resistivity silicon. By leveraging the memory properties of PCM switches, the proposed circuit enables precise postfabrication adjustments to compensating for active device variations. The measured <italic>L</i>–<italic>C</i> circuit inductor is tuned from 1.3 to 1.6 nH by switching its parallel capacitance, while the capacitor is adjusted from 0.7 to 1.2 pF, resulting in four distinct impedance states. The measured total insertion loss ranges from −1.62 to −2.95 dB, showing good agreement with simulations. The complete circuit occupies an area of <inline-formula> <tex-math>$332times 363~mu $ </tex-math></inline-formula>m<sup>2</sup>, which is nearly identical to its fixed version.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1340-1343"},"PeriodicalIF":3.4,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078668","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 Air-Filled Cavity Bandpass Filter Processed by Microstructure Electrochemical Fabrication With Self-Supported GSG Feeding Probe","authors":"Feng Huang;Jing Zhou;Wanping Zhang;Lijie Xu;Bo Li;Lei Zhu","doi":"10.1109/LMWT.2025.3581334","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3581334","url":null,"abstract":"In this letter, a bandpass filter (BPF) operating at the <italic>W</i> band is presented by utilizing microstructure electrochemical fabrication (MEFAB) technology. The BPF is made up of two coupled air-filled rectangular cavities which are purposely developed for a second-order Chebyshev response. Inside each cavity, half-wavelength short-circuited stubs are attached to support the vertical ground-signal–ground (GSG) feeding probes. Naturally, by means of adjusting the relative position of two feeding probes, extra transmission zeros (TZs) can be introduced to improve the out-of-band rejection. Finally, a practical air-cavity filter is fabricated for validation. The measured results show good agreement with the simulated ones, exhibiting a low in-band insertion loss of about 0.66 dB and the 3-dB fractional bandwidth (FBW) of 3.6% with the central frequency at 94 GHz.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1280-1283"},"PeriodicalIF":3.4,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078654","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}
Xiaopan Chen;Yongle Wu;Zhuoyin Chen;Moushu Yang;Shuchen Zhen;Weimin Wang
{"title":"Fully Integrated GaAs MMIC Bandpass Filtering Power Amplifier Chip With Compact Couple-Line-Based Matching Network","authors":"Xiaopan Chen;Yongle Wu;Zhuoyin Chen;Moushu Yang;Shuchen Zhen;Weimin Wang","doi":"10.1109/LMWT.2025.3578722","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3578722","url":null,"abstract":"This letter presents a novel bandpass filtering power amplifier (FPA) structure featuring a dc-block input matching network (IMN), which utilizes a filtering impedance transformer consisting of two cascaded coupled-lines, a short-circuit coupled-line (SCCL), and a parallel resonator (PR). The SCCL generates transmission zeros (TZs) near the passband, enabling sharp roll-off characteristics. The PR enhances filtering response while occupying minimal circuit area. For verification, a monolithic microwave-integrated circuit (MMIC) FPA using 0.25-<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m GaAs process was designed and fabricated, implementing serpentine routing for a highly compact layout. The measurement results demonstrate 30-dB out-of-band rejection, 27-dBm output power, and 46%–55% drain efficiency (DE) in 9–11 GHz. The adjacent channel power ratio (ACPR) is lower than −48.4 dBc with digital predistortion (DPD) using a 60-MHz 64-QAM 5G-NR signal.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1416-1419"},"PeriodicalIF":3.4,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078680","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 10–60-GHz LNA With 3.2–4.4-dB NF for Wideband Applications in 16-nm FinFET Process","authors":"Ahmed Helaly;Mohammed Helal;Gabriel M. Rebeiz","doi":"10.1109/LMWT.2025.3577982","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3577982","url":null,"abstract":"This letter presents a 10–60-GHz low-noise amplifier (LNA) implemented in CMOS FinFET technology. The LNA consists of four gain-staggered cascode stages to cover the wide bandwidth. Resistive feedback and multipole loads are used to achieve wideband operation. A high coupling coefficient balun is used to generate a differential output signal. The LNA has a measured small-signal peak gain of 23 dB with a noise figure (NF) of 3.2–4.4 dB. The LNA also achieves an output-referred 1-dB compression point of 0 dBm at the center frequency of the band and consumes a total power of 32 mW occupying an active area of <inline-formula> <tex-math>$0.8times 0.29~text {mm}^{2}$ </tex-math></inline-formula>. Application areas are phased arrays covering multiple 5G bands and multistandard receivers.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1360-1363"},"PeriodicalIF":3.4,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078599","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 Novel Group Delay Controller Based on Reflective Tunable Filter","authors":"Xinyi Chen;Qianyin Xiang","doi":"10.1109/LMWT.2025.3579399","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3579399","url":null,"abstract":"This letter introduces a group delay controller (GDC) based on reflective tunable filter with tunable frequency and tunable group delay. The wideband nonlinear conversion of the reflective low-pass delay network to the reflective bandpass delay network was studied, and the deterioration of tunable group delay response was analyzed. Asymmetric tuned reflective topology with self-coupling coefficients was used to compensate for the flatness of the in-band group delay. As a demonstration, a reflective tunable group delay circuit was designed based on tunable quarter-wavelength microstrip resonator and feeding network with tunable external quality factor (<inline-formula> <tex-math>$Q_{e}$ </tex-math></inline-formula>). The measurements show that the GDC can be tuned from 8 to 20 ns, with a tunable center frequency from 0.8 to 1 GHz.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1300-1303"},"PeriodicalIF":3.4,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078600","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 K-Band Reconfigurable GaN Power Amplifier Using Switch-Loaded Coupled Line","authors":"Xin He;Haoshen Zhu;Dingyuan Zeng;Zhikai Hu;Shaowei Liao;Quan Xue","doi":"10.1109/LMWT.2025.3578417","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3578417","url":null,"abstract":"This letter presents a K-band power amplifier (PA) monolithic microwave integrated circuit (MMIC) with frequency reconfigurable operation in a 0.15-<inline-formula> <tex-math>$mu text {m}$ </tex-math></inline-formula> GaN-on-SiC process. The proposed reconfigurable PA (RPA) is composed of a broadband output power stage and a driver stage with a reconfigurable interstage matching network (ISMN). Frequency reconfiguration is achieved by combining and embedding a switch-loaded coupled line (SLCL) and a switch-loaded transmission line (SLTL) inductor within the ISMN. The operating frequency band of the proposed RPA can be changed using the switch device in ISMN. Measurements results indicate that the proposed RPA features a maximum power-added efficiency (PAE) of 26.5% and an output power of over 30 dBm at a lower frequency band (19.5–21.5 GHz). When configured at a higher frequency operating mode, the RPA achieves a maximum PAE of 21% and an output power over 30 dBm at 23.5–25.5 GHz. The modulation tests are performed using a 100-MHz 64-QAM modulated signal with 6.09-dB peak-to-average power ratio (PAPR). The proposed RPA achieves better than −27.5-dBc adjacent channel leakage ratio (ACLR) at 19.5 GHz and −29 dBc at 24.5 GHz without digital predistortion (DPD), respectively.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1408-1411"},"PeriodicalIF":3.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078684","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}
M. Baranowski;A. Pons-Abenza;I. Arregui;T. Lopetegi;G. Álvarez-Botero;A. Lamecki;M. A. G. Laso;P. Martin-Iglesias
{"title":"A 3-D-Printing-Oriented Coaxial-Line Filter With Wide Out-of-Band Rejection","authors":"M. Baranowski;A. Pons-Abenza;I. Arregui;T. Lopetegi;G. Álvarez-Botero;A. Lamecki;M. A. G. Laso;P. Martin-Iglesias","doi":"10.1109/LMWT.2025.3578244","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3578244","url":null,"abstract":"In this letter, a novel design for a 3-D-printed, self-supported coaxial-line X-band filter is presented. The filter is intended for Earth observation (EO) data downlink systems, where it must effectively reject signals in a wide frequency range. The filter design incorporates a 15th-order low-pass filter structure with a smooth profile, integrated with a short bandpass section with four <inline-formula> <tex-math>$lambda /4$ </tex-math></inline-formula> short-circuited stubs. The optimization of the low-pass section is attained by means of shape deformation, including the inner and outer coaxial conductors, and leads to a wide rejection band up to around 40 GHz, to suppress the third harmonic and other undesired out-of-band frequencies. A prototype was fabricated in one piece in an aluminum alloy using selective laser melting (SLM) and measured, exhibiting excellent agreement with simulations. In terms of out-of-band performance, the proposed coaxial-line filter is superior to other related state-of-the-art solutions.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1292-1295"},"PeriodicalIF":3.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078605","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}
Xinyu Zhang;Yongle Wu;Wei Zhao;Shiyu Xie;Zhuoyin Chen;Weimin Wang
{"title":"A Novel IPD-Based Dual-Band Filtering Power Divider Chip Across X-Band and K-Band","authors":"Xinyu Zhang;Yongle Wu;Wei Zhao;Shiyu Xie;Zhuoyin Chen;Weimin Wang","doi":"10.1109/LMWT.2025.3578707","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3578707","url":null,"abstract":"This letter presents a compact dual-band filtering power divider (DBFPD) based on a novel dual-<inline-formula> <tex-math>$pi $ </tex-math></inline-formula>-type matching circuit (MC). The proposed dual-<inline-formula> <tex-math>$pi $ </tex-math></inline-formula>-type MC achieves precise dual-band matching through analytical design, and integrated hybrid resonators (HRs) significantly enhance the bandwidth of passbands. Three independently controllable transmission zeros (TZs) of DBFPD improve stopband rejection and frequency selectivity. To validate the design, a DBFPD working at 8.9 and 21.6 GHz with a compact size of <inline-formula> <tex-math>$1.9times 3.1$ </tex-math></inline-formula> mm<sup>2</sup> is fabricated and measured using integrated passive device (IPD). The design achieves low insertion loss (IL) and wide bandwidth, with minimum ILs of 0.43 and 0.47 dB and 3-dB bandwidths of 50% and 33.5%, respectively.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 9","pages":"1420-1423"},"PeriodicalIF":3.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078604","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}