Microwave and Optical Technology Letters最新文献

{"title":"A Tri-Band Bandpass Filter Loaded With Dual-Function l-Shaped Stubs","authors":"Xinying Sun,&nbsp;Chuicai Rong","doi":"10.1002/mop.70414","DOIUrl":"https://doi.org/10.1002/mop.70414","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a novel planar tri-band bandpass filter (BPF) composed of a uniform impedance resonator (UIR) loaded with short-circuit stubs and a set of stepped impedance resonators (SIRs) loaded with dual-function <span>l</span>-shaped stubs. The UIR with short-circuit stubs operates in the second passband, while the SIRs generate the first and third passbands. Compared to traditional open stubs, the proposed <span>l</span>-shaped stubs not only adjust the position of the third band but also improve its performance. The equivalent circuit is analyzed using odd-even mode theory. By introducing source-load coupling at the feed lines, transmission zeros are created between the passbands, enhancing selectivity. To validate the design, a compact tri-band BPF centered at 2.4 GHz, 4.0 GHz, and 5.0 GHz was fabricated and measured. The results demonstrate excellent insertion loss and return loss performance.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110745","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}

{"title":"Power-Dependent Modeling of Microwave FET Intrinsic Elements Using X-Parameters","authors":"Alfredo Sánchez-Ramos,&nbsp;José Raúl Loo-Yau,&nbsp;Ernesto Alejandra Hernández-Domínguez,&nbsp;Manuel Alejandro Pulido-Gaytán,&nbsp;J. Apolinar Reynoso-Hernández,&nbsp;Pablo Moreno","doi":"10.1002/mop.70411","DOIUrl":"https://doi.org/10.1002/mop.70411","url":null,"abstract":"<p>This study introduces and validates an alternative approach for modeling microwave FETs using power-dependent electrical equivalent circuits extracted from conventional <i>X</i>-parameters (<i>Z</i>_<i>L</i> = 50 Ω). The proposed method expands the use of the conventional <i>X</i>-parameters measurements by generating a model that is more practical and intuitive. It enables the extraction of intrinsic elements through a procedure similar to that used in small-signal analysis. Moreover, the nonlinear intrinsic elements are expressed as functions of input power, and the resulting model can be readily implemented in commercial microwave simulators. Experimental validation using the GaN FET CGH40010F demonstrates that the proposed model achieves improved prediction accuracy for power-added efficiency (PAE) and drain efficiency compared to the manufacturer's model. One-tone test errors are below 5 dB, PAE prediction errors are under 2%, and the estimation of the optimal load impedance for maximum PAE is significantly more accurate with the proposed model.</p>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mop.70411","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Design of Multi-Octave Power Amplifier Based on Multipath Harmonic Matching Structure","authors":"Baoquan Zhong,&nbsp;Minshi Jia,&nbsp;Zhiqun Cheng,&nbsp;Bingxin Li,&nbsp;Kun Wang,&nbsp;Zhenghao Yang,&nbsp;Zheming Zhu","doi":"10.1002/mop.70406","DOIUrl":"https://doi.org/10.1002/mop.70406","url":null,"abstract":"<div>\u0000 \u0000 <p>In this paper, a novel broadband output matching network (OMN) is proposed for the design of extended continuous class-F (ECCF) power amplifiers (PAs) with a bandwidth of more than one octave. This OMN utilizes a multipath impedance matching structure, in which six frequency points in the target band are selected and then efficiently matched to the optimal impedance region provided by the ECCF PA. This approach not only realizes a high-efficiency PA but also extends the bandwidth. To verify the effectiveness of the proposed structure, a PA is designed and implemented using a commercial gallium nitride (GaN) high electron mobility transistor (HEMT). This PA operates from 0.5 to 3.0 GHz, exhibiting a relative bandwidth of 143%. Measured results demonstrate a drain efficiency (DE) of 61.2%–73.9%, an output power (Pout) of 39.5–42.2 dBm, and a gain of 9.5–12.2 dB over the entire operating band.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110744","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}

{"title":"Design and Characterization of MSAP-Fabricated Sub-THz Frequency Selective Surface by Bench-Top Optoelectronic Measurement System","authors":"Keigan Macdonell,&nbsp;Takashi Tomura,&nbsp;Shulabh Gupta","doi":"10.1002/mop.70385","DOIUrl":"https://doi.org/10.1002/mop.70385","url":null,"abstract":"<p>A low-cost and compact benchtop using the off-the-shelf optoelectronic (OE) measurement system is presented which is built to measure the performance of a 160 GHz frequency selective surface (FSS). The system uses an optical heterodyne source to excite wireless signals through the -D-band (110–170 GHz), and transmission magnitude is measured using a frequency-extended power spectrum analyzer (PSA). The system is shown to perform well towards characterizing an FSS structure fabricated using a modified semi-additive process (MSAP), with the magnitude shown to agree well with both full-wave simulation of the array and measurements taken using a conventional microwave measurement setup. While the noise floor of the measurement system limits the ability to characterize FSS attenuation below –16 dB, the reduction in transmitted power at the design frequency is clearly captured. The OE measurement system represents an approach to analyzing sub-THz frequency wireless devices that will play an essential role in the development and adoption of next-generation wireless communications.</p>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mop.70385","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145110746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Radio Over Fiber Millimeter Wave Generation for 5G Communication Applications","authors":"Krishna Mari Selvi T,&nbsp;Suganthi Santhanam","doi":"10.1002/mop.70395","DOIUrl":"https://doi.org/10.1002/mop.70395","url":null,"abstract":"<div>\u0000 \u0000 <p>Radio Frequency (RF) waves at 2.5 and 5 GHz have been used to generate millimeter (mm) wave frequencies at 90 and 180 GHz using two cascaded dual parallel Mach–Zehnder modulators (DP-MZM). In Radio over Fiber (RoF), 36-tupling is employed to maximize the signal quality by modifying the bit rate up to 20 Gbps over a 50 km single-mode fiber distance. The characteristics research is graphically analyzed in terms of fiber length, bit error rate, quality factor, Optical Sideband Suppressing Ratio (OSSR), and Radio Frequency Spurious Sideband Suppressing Ratio (RFSSR) at 10 and 20 Gbps with a minimal Bit Error Rate (BER) of 10⁻⁹. The performance of the generated millimeter wave was evaluated at the receiver. Furthermore, the consistency of the theoretical and simulation results proved the usefulness of the system.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102142","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}

{"title":"Multilayer Cross-Coupled Substrate Integrated Waveguide Filter With Quasi-Elliptic Response and Wide Stopband","authors":"Peng Chu,&nbsp;Jialong Zhou,&nbsp;Wenyu Zhang,&nbsp;Li Cheng,&nbsp;Leilei Liu,&nbsp;Ke Wu","doi":"10.1002/mop.70407","DOIUrl":"https://doi.org/10.1002/mop.70407","url":null,"abstract":"<div>\u0000 \u0000 <p>Substrate integrated waveguide (SIW) filters usually employ cross-coupling to produce quasi-elliptic responses to achieve steep selectivity near the passband. But the added cross-coupling enables additional transmission of spurious modes and facilitates the generation of spurious passbands, which degrades stopband selectivity and is challenging to address effectively without cascading additional filters or using hybrid resonant structures. This letter proposes a solution. By specially arranging the positions of the coupling structures in a TE₁₀₁ cross-coupled SIW filter, TE₁₀₂ and TE₂₀₁ cannot couple/transmit through both the main and cross-coupling structures. Furthermore, by using a multilayer structure and exchanging the position of the electric coupling, the superior shielding and quality factor of SIW can be maintained. And these operations can be performed without affecting the TE₁₀₁ quasi-elliptic response. As a result, the proposed multilayer cross-coupled SIW filter can effectively achieve a wide stopband in addition to the quasi-elliptic response, and is suitable for integration in high-performance and high-frequency applications. It should be effective for developing SIW filters in wireless and microwave circuits and systems.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102143","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}

{"title":"Design of a Compact Broadband X-Band Reflectarray Antenna Using an Archimedean–Sinusoidal Hybrid Element","authors":"Sheng Kang,&nbsp;Li Liu,&nbsp;Yufeng Liu,&nbsp;Jiao Zhang,&nbsp;Guorui Han,&nbsp;Liping Han","doi":"10.1002/mop.70408","DOIUrl":"https://doi.org/10.1002/mop.70408","url":null,"abstract":"<div>\u0000 \u0000 <p>This letter proposes a single-layer X-band reflectarray antenna employing an Archimedean–sinusoidal hybrid element in a subwavelength configuration. By integrating sinusoidal perturbations into four-arm Archimedean spirals, the unit cell achieves an extended reflection-phase range (~550° at 10 GHz) and improved phase linearity while maintaining a compact 0.4<i>λ</i>₀ periodicity. To enhance the bandwidth, a Vivaldi antenna is employed as the feed source, ensuring reflection coefficients below − 10 dB across the X-band. By arranging mirror-symmetric elements, the cross-polarization of the reflectarray is effectively suppressed. An 11 × 11 prototype antenna was designed, fabricated, and measured, achieving a peak gain of 18.9 dBi at 10.4 GHz. The measured 3-dB gain bandwidth is 30.7% (8.29–11.36 GHz), and the measured cross-polarization and sidelobe levels are − 20.8 dB and − 7.1 dB, respectively.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102141","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}

{"title":"A Radar Path Loss Prediction Method for Nearshore Wind Farm Environments","authors":"Qixiang Ouyang,&nbsp;Xuanming Zhong,&nbsp;Ju Feng,&nbsp;Hongxin Yu,&nbsp;Junbing Duan,&nbsp;Cheng Liao","doi":"10.1002/mop.70403","DOIUrl":"https://doi.org/10.1002/mop.70403","url":null,"abstract":"<div>\u0000 \u0000 <p>To address the challenge of predicting radar signal path loss in complex nearshore wind farm environments, this letter proposes a hybrid method combining the pseudo-3D parabolic equation and Fresnel-Kirchhoff diffraction theory. The pseudo-3D parabolic equation method is used to compute environmental path loss by incorporating complex geographical and meteorological conditions into the electromagnetic model. To account for the additional diffraction effects introduced by wind turbines, a supplementary model based on Fresnel–Kirchhoff diffraction theory is integrated. This combined approach enables accurate and comprehensive path loss prediction across the entire wind farm environment. To validate the proposed method, a numerical example under a simplified scenario was conducted and compared with results from the 3D parabolic equation method. The proposed method significantly improved computational efficiency while maintaining a root mean square error below 0.63 dB, demonstrating its high efficiency and accuracy. Further numerical simulations were conducted in a nearshore environment using digital maps, aiming to analyze the impact of wind farms on radio wave propagation from shore-based radar. The results indicate the presence of a pronounced fan-shaped affected zone behind the wind farm, within which the environmental path loss exhibits significant spatial nonuniformity.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101708","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}

{"title":"A New Compact Switching Bandpass Filter Using Only a Single Pin Diode","authors":"Jinhai Tang,&nbsp;Xinhua Yu,&nbsp;Linping Feng","doi":"10.1002/mop.70396","DOIUrl":"https://doi.org/10.1002/mop.70396","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents an innovative integrated switchable single-pole double-throw (SPDT) switch for bandpass filters (BPFs) using a terminal-loaded coupled line structure. Based on the design principles of terminal-loaded coupled line structures, the proposed SPDT switch achieves a bandpass on-state when the p-i-n diodes are reverse-biased, and a high off-state suppression through detuning when forward-biased. The on-state passband selectivity is further enhanced by introducing two pairs of transmission zeros, created by symmetrically loaded series stubs at the coupled line ports. A prototype switch, designed for operation at 1 GHz with a bandwidth of 411 MHz, achieves a low insertion loss of 1.3 dB, a high roll-off rate, and a strong off-state rejection of 24 dB.</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101389","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}

{"title":"A Compact Ultra-Wideband Omnidirectional Cavity-Backed Antenna for UAV Communication","authors":"Jiang-Lou Xue,&nbsp;Shi-Wei Qu,&nbsp;Chao Sun,&nbsp;Chen Chen","doi":"10.1002/mop.70380","DOIUrl":"https://doi.org/10.1002/mop.70380","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper presents a compact ultra-wideband omnidirectional cavity-backed antenna for UAV communication systems. The monocone antenna is embedded within a metallic cavity to enable flush-mounted installation, thereby preventing aerodynamic performance degradation of aircraft. The integration of a coupling ring with four resistor-loaded shorting stubs effectively reduces the antenna's lowest operating frequency, enabling simultaneous antenna miniaturization and broadband performance. The proposed antenna is designed, fabricated, and tested to verify its performance. Measured and simulated results indicate that the antenna exhibits a 114% relative bandwidth (0.52–1.90 GHz) with a voltage standing wave ratio less than 3. The metallic cavity of the proposed antenna features dimensions of 0.36<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>L</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{L}$</annotation>\u0000 </semantics></math> × 0.36<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>L</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{L}$</annotation>\u0000 </semantics></math> × 0.062<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>L</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{L}$</annotation>\u0000 </semantics></math> (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 \u0000 <mrow>\u0000 <msub>\u0000 <mi>λ</mi>\u0000 \u0000 <mi>L</mi>\u0000 </msub>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation> ${lambda }_{L}$</annotation>\u0000 </semantics></math> is the free-space wavelength at the lowest operating frequency).</p>\u0000 </div>","PeriodicalId":18562,"journal":{"name":"Microwave and Optical Technology Letters","volume":"67 9","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101446","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}