IEEE Transactions on Microwave Theory and Techniques最新文献

{"title":"Microstructured Water-Based Broadband Terahertz Pyramidal Absorber","authors":"Kalliopi Spanidou;Daniel Headland;Sharath Sriram;Itziar Maestrojuán Biurrun;Guillermo Carpintero","doi":"10.1109/TMTT.2025.3580219","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3580219","url":null,"abstract":"The presence of multipath effects in terahertz wireless links degrades signal quality, making absorbers a critical component of 5G/6G wireless systems. Here, we leverage the innately high loss of liquid water, combined with the microscale precision of UV-cured resin-based micro 3-D printing, to realize a viable pyramidal absorber for terahertz waves. Both simulation and experimental results confirm near-unity absorption, achieving over 99% in the 75–190 GHz range and 99.99% over 190–500 GHz. Furthermore, simulations show that the absorber maintains high performance up to 1000 GHz, with absorption exceeding 99.999%. These results demonstrate potential for future micro 3-D-printed resin-based absorbers that can be readily tailored to serve in communication, sensing, and radar applications, thanks to their microscale size, cost-effectiveness, and adaptability to broadband terahertz wireless systems.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"5992-6000"},"PeriodicalIF":4.5,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11053690","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-Dimensional Printed mm-Wave Monolithic Waveguide Twists: End-to-End Manufacturing and Surface-Treatment Solutions","authors":"Lu Qian;Talal Skaik;Yi-Wen Wu;Yi Wang","doi":"10.1109/TMTT.2025.3577733","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3577733","url":null,"abstract":"This article presents an end-to-end manufacturing and post-processing solution for 3-D-printed millimeter-wave (mm-Wave) monolithic waveguide (WG) components. A high-precision micro laser sintering (MLS) process, two internal surface polishing methods—abrasive flow machining (AFM) and Hirtisation—and an electroless gold plating process are combined to address the surface quality challenges commonly associated with current 3-D-printed mm-Wave components. This is the first demonstration of the two polishing techniques on mm-Wave devices. An experimental study was conducted on two mm-Wave WG twists for WR-15 and WR-5 bands, respectively. The impact of the surface treatment processes on both mechanical and electrical properties was investigated. The surface roughness of both WG twists was reduced to below <inline-formula> <tex-math>$1~mu $ </tex-math></inline-formula>m. For the WR-15 WG twist, the dissipative attenuation factor ranged from 5.4 to 2.7 dB/m, with a worst case return loss of 30 dB. For the WR-05 WG twist, the dissipative attenuation factor ranged from 17 to 10 dB/m, with a worst case return loss of 14 dB. The significant improvement in insertion losses (ILs) demonstrates the effectiveness of the two surface treatment methods, enabling complex monolithic mm-Wave WG components with enhanced surface quality.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"5909-5917"},"PeriodicalIF":4.5,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3-D-Printed Doubly-Curved Multilayer Tri-Band Frequency Selective Surface","authors":"Sebastian Mettes;Christopher T. Howard;Joshua Roper;Taylor M. Shapero;Kenneth W. Allen;Yi Chen Mazumdar","doi":"10.1109/TMTT.2025.3577467","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3577467","url":null,"abstract":"Advances in computational design methods have enabled the development of increasingly sophisticated frequency selective surfaces (FSSs). However, manufacturing these complex designs on doubly-curved shapes remains challenging. In this work, we design, fabricate, and experimentally validate an additively manufactured, doubly-curved, multimaterial, and multilayer FSS subreflector for L passband and Ku and Ka stopband frequencies. By employing this subreflector in a Cassegrain antenna configuration, broadband satellites operating in the Ku-Ka-bands can gain access to L-band frequencies without the need for separate antenna systems. To achieve the desired tri-band frequency response, the FSS elements are first synthesized using periodic level set functions with a target passband from 1 to 6 GHz and stopbands from 17.7 to 20.2 and 27.5 to 30.0 GHz. Then, a planar FSS sample is 3-D-printed using fused filament fabrication (FFF) for the dielectric layers and direct ink write (DIW) with silver nanoparticle ink for the conductive layers. Sample testing in a free space focused beam indicates good agreement with the simulation results. Next, spatially variant lattices (SVLs) are employed to map the synthesized elements onto a hyperbolic surface and advanced, nonplanar 3-D-printing techniques are implemented to manufacture the doubly-curved FSS subreflector. These techniques greatly improve surface quality and enable the printing of multiple layers of continuous conductive patterns on curved surfaces. To demonstrate the performance of the subreflector, it is tested in a Cassegrain antenna system on a compact range with experimental results showing fair agreement with simulation results. Overall, these findings demonstrate the potential for advanced additive manufacturing (AM) to produce high-performance, conformal FSS structures for next-generation radome and spectral filtering applications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"5864-5875"},"PeriodicalIF":4.5,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial—IEEE T-MTT Mini Special Issue Featuring WPTCE 2024","authors":"Ramesh Pokharel;Kenjiro Nishikawa;Hiroo Sekiya","doi":"10.1109/TMTT.2025.3572637","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3572637","url":null,"abstract":"","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 6","pages":"3344-3345"},"PeriodicalIF":4.1,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11033169","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-Cost Rectangular Coaxial Transversal Filters With Additive Manufacturing Insulator Support and Enhanced Out-of-Band Performance","authors":"Xuzhou Yu;Lei Zhu;Jia-Xiang Hao;Shuangxu Li","doi":"10.1109/TMTT.2025.3573791","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3573791","url":null,"abstract":"In this article, several low-cost transversal filters are proposed by rectangular coaxial transmission line resonators with additive manufacturing insulator supports, and their filtering characteristics are synthesized. First, the working principle of the transmission zeros (TZs) of the transversal filter is investigated thoroughly. Next, the transversal filter is revealed with its unique ability in generating <italic>N</i> TZs in an <italic>N</i>th-order filter with no additional structure, which is competitive in the filter synthesis theory. Then, the configuration and unloaded <italic>Q</i> factor <inline-formula> <tex-math>$Q_{u}$ </tex-math></inline-formula> of the proposed resonator are investigated to show its enhanced <inline-formula> <tex-math>$Q_{u}$ </tex-math></inline-formula>, and the proposed resonator is exhibited with good accuracy during assembly and <inline-formula> <tex-math>$Q_{u}$ </tex-math></inline-formula> is competitive. Hence, the characteristics of the resonator are studied with respect to the electrical length, the characteristic impedance <inline-formula> <tex-math>$Z_{0}$ </tex-math></inline-formula>, the feeding structure, and the extracted external coupling <inline-formula> <tex-math>$Q_{e}$ </tex-math></inline-formula>. To verify the generality of our proposed synthesis of transversal filters with rectangular coaxial-line resonators, three bandpass filter prototypes are synthesized and simulated. As the order increases, all three filters achieve the same number of TZs as their filter order. Finally, the fourth-order transversal bandpass filter is fabricated and measured, the conductors are fabricated by CNC techniques, and the low-cost insulator supports are manufactured by 3-D printing techniques. The measured results are found in good agreement with the synthesized and simulated ones. The center frequency is at 2.00 GHz with 6.50% fractional bandwidth (FBW) and four TZs occur outside the passband. In addition, the measured insertion loss (IL) is around 0.70 dB, which is pretty competitive. Compared with other published transversal filters, the out-of-band performance of the proposed coaxial-line transversal filter is highly enhanced.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"5851-5863"},"PeriodicalIF":4.5,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Low-Loss Scalable Fan-Out Wafer Level Packaging for W-Band Phased Array Transceiver","authors":"Ding Wang;Hong Bin Hu;Qi Peng;Chen Hui Xia;Yu Hang Yin;Ning Yang;Xiao Lin Qi;Yong Fan;Yu Jian Cheng","doi":"10.1109/TMTT.2025.3571627","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3571627","url":null,"abstract":"This article introduces a low-cost compact W-band <inline-formula> <tex-math>$4times 4$ </tex-math></inline-formula> phased array antenna utilizing fan-out wafer-level package (FOWLP) for high-performance applications. The package, measuring <inline-formula> <tex-math>$8.3times 7.1$ </tex-math></inline-formula> mm, integrates a 16-channel transceiver die. To minimize the insertion loss and enhance impedance matching across the W band, the design incorporates an air-filled grounded coplanar waveguide (AF-GCPW) transmission line. An innovative thermal management strategy, which includes ball grid arrays (BGAs) and embedded copper slugs in the PCB, ensures efficient heat dissipation. Experimental results reveal that the array can achieve scanning capabilities of ±40° in the <italic>H</i>-plane and ±30° in the <italic>E</i>-plane, with an effective isotropic radiated power (EIRP) of 35 dBm at 94 GHz. The proposed phased array demonstrates superior performance compared to existing designs by reducing packaging loss, minimizing the number of metal layers, and enhancing cost-effectiveness. Consequently, it emerges as a promising solution for radar and sensing applications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"5966-5978"},"PeriodicalIF":4.5,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Millimeter-Wave Wide-Angle Ridge Gap Waveguide Multibeam Antenna Fed by 3-D Printing Butler Matrix","authors":"Chuhan Wei;Yang Liu;Ji-Wei Lian;Chun Geng;Dazhi Ding","doi":"10.1109/TMTT.2025.3562201","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3562201","url":null,"abstract":"A novel 3-D printing ridge gap waveguide (RGW) wide-angle endfire dual-dipole multibeam antenna operating at millimeter-wave (mmW) frequency spectrum is proposed, which consists of an RGW <inline-formula> <tex-math>$6times 6$ </tex-math></inline-formula> Butler matrix (BM) and an endfire dual-dipole antenna array. This article provides a detailed description of the working principle and design process of the <inline-formula> <tex-math>$6times 6$ </tex-math></inline-formula> BM. By incorporating RGW technology, transmission losses of the beamforming network (BFN) are effectively reduced, which enhances the radiation efficiency of the final multibeam antenna. A modified endfire dual-dipole antenna with wide beamwidth is introduced. By integrating the <inline-formula> <tex-math>$6times 6$ </tex-math></inline-formula> BM with the endfire dual-dipole antenna array, the final multibeam antenna is realized. This antenna provides a maximum scanning-plane half-power beamwidth (HPBW) coverage of ±83.5° and an associated gain varying from 12.3 to 13.8 dBi at 28 GHz. Furthermore, an analysis is conducted on the fabrication issues related to manufacture tolerance and surface roughness in 3-D printing processes, which evaluate the ability and accuracy of 3-D printing technology in mmW antenna applications.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"5791-5802"},"PeriodicalIF":4.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A High-Power AlGaN/GaN Nonlinear Transmission Line Frequency Comb Generator With Stable Multiplication Efficiency","authors":"Lanyong Xiang;Hanze Chen;Jiandong Sun;Yang Shangguan;Jinfeng Zhang;Lin Jin;Xinxing Li;Hua Qin","doi":"10.1109/TMTT.2025.3560623","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3560623","url":null,"abstract":"In this article, an innovative nonlinear transmission line (NLTL) is presented to obtain a high-power frequency comb. A stable efficiency is realized by introducing quasi-stepped capacitance into the NLTL, where the power of the output frequency comb can be continuously raised with the increase of the input power. AlGaN/GaN Schottky barrier diodes (SBDs) with quasi-stepped capacitance are used to compose the NLTL. With an input frequency of 4 GHz, a series of frequency comb from 4 to 24 GHz is generated. The output power varies linearly with the input power range of 15–35 dBm and the harmonic power at 20 GHz is 0 dBm at the input power of 35 dBm. The NLTL saturates at a higher input power, which is caused by the forward-conduction characteristics of AlGaN/GaN SBD, and the saturation power can be improved by depositing a dielectric layer under the anode of SBD. An NLTL-based frequency comb generator is designed utilizing an SBD with a cutoff frequency of 270 GHz. Under a 4 GHz input signal, the 50th harmonic exhibited stable efficiency at −40 dB, showing its potential for terahertz sources, broadband heterodyne receivers, and high-frequency sampling circuits.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6139-6148"},"PeriodicalIF":4.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Additive Phase-Noise Reduction in Microwave Regenerative Dividers","authors":"Samin Hanifi;Pedram Shirmohammadi;Steven M. Bowers","doi":"10.1109/TMTT.2025.3561436","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3561436","url":null,"abstract":"A detailed investigation of a method to effectively reduce additive phase noise in regenerative frequency dividers is presented. The approach enhances the sensitivity of conventional regenerative dividers and addresses start-up challenges while preserving low-additive phase noise and low power consumption. As a proof of concept, an integrated low-additive phase-noise regenerative divider with an octave-spanning frequency range was designed and fabricated using a 250-nm InP heterojunction bipolar transistor (HBT) process. The impact of the classes of operation for both the amplifier and the buffer, along with the effect of the phase shifter, on the divider’s overall phase-noise performance was analyzed and measured. The regenerative divider achieved additive phase noise below −163 dBc/Hz from a 7-GHz carrier at 10-kHz offset with more than 12-dB fundamental rejection and greater than −10-dBm output power at various frequencies. The presented results, with the full integration of the divider, address key challenges in low-additive phase-noise design, representing a significant advancement for low-noise applications, including communication and navigation systems.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6326-6338"},"PeriodicalIF":4.5,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Accuracy Wideband Frequency Measurement With Dual Optical Combs Using Solution Space Partitioning Method","authors":"Meiling Yang;Shenshen Luan;Xuchun Hao;Shuguo Xie;Yan Yang","doi":"10.1109/TMTT.2025.3559211","DOIUrl":"https://doi.org/10.1109/TMTT.2025.3559211","url":null,"abstract":"Noncooperative electromagnetic radiation source sensing faces challenges such as wide bandwidth and an unknown number of sources, which hinder various applications like electromagnetic compatibility, radar detection, and passive positioning. Traditional sweep reception methods, based on antennas and superheterodyne receivers, struggle to meet real-time requirements. Optical undersampling sensing technologies enable rapid reception in ultrawideband. Frequency measurement in these systems, however, requires triple-comb or higher-dimensional information, introducing complexity and instability. The dual-comb-based frequency measurement method is further complicated by dead zones due to its underdetermined nature. In this article, we demonstrate, for the first time, the boundedness and reachability of the solution to the dual-comb ultrawideband frequency measurement problem. We propose a boundary determination method that ensures error-free solutions. Simulation and experimental results demonstrate that our method achieves 98% accuracy for a single source with seven octave bandwidths and over 90% accuracy for the coexistence of two-five sources. This method can achieve accurate measurement with only a 5 dB signal-to-noise ratio (SNR) and exhibits high robustness. Our work clearly defines the theoretical limits of frequency measurement for dual-comb undersampling systems, significantly enhancing both test accuracy and engineering practicability. This method can be widely applied to frequency measurement and signal estimation in RF and optical systems, paving new high-speed, accurate and robust pathways in microwave photonics metrology and ultrawideband signal processing.","PeriodicalId":13272,"journal":{"name":"IEEE Transactions on Microwave Theory and Techniques","volume":"73 9","pages":"6759-6773"},"PeriodicalIF":4.5,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145073210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}