Jinglong Xu;Mohamed Eleraky;Tzu-Yuan Huang;Chenhao Chu;Hua Wang
{"title":"A Compact Doubly Neutralized Ku-Band Power Amplifier With 39% Peak PAE and 23-dBm Output Power in 22FDX+ EDMOS for 6G FR3","authors":"Jinglong Xu;Mohamed Eleraky;Tzu-Yuan Huang;Chenhao Chu;Hua Wang","doi":"10.1109/LMWT.2025.3566279","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3566279","url":null,"abstract":"This letter presents a compact, doubly neutralized, two-stage power amplifier (PA) utilizing the new extended drain (EDMOS) device in 22FDX+, designed for 6G frequency range 3 (FR3) and Ku-band applications. Cascode double neutralization is proposed and analyzed in detail to demonstrate its necessity for the stability of RF/mmWave PA designs in scaled technology nodes. The PA achieves a <inline-formula> <tex-math>$P {_{text {SAT}}}$ </tex-math></inline-formula> of 23.55 dBm and a PAE<sub>MAX</sub> of 39.27% at 12 GHz. To the best of the authors’ knowledge, this work demonstrates the highest reported power density of 1.49 W/mm<sup>2</sup> using only a 2.4-V supply, thanks to the EDMOS device. Furthermore, it represents the first demonstration of a CMOS PA in 6G FR3 supporting the broadest complex modulation bandwidth, achieving 4250 MHz with 64-QAM and 1250 MHz with 256-QAM signals.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"856-859"},"PeriodicalIF":0.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299239","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 Millimeter-Wave Analog–Digital Variable Capacitor With High Tuning Ratio Realized by Monolithic Integration of BST Varactors and GeTe Switches","authors":"Mehran Golcheshmeh;Raafat R. Mansour","doi":"10.1109/LMWT.2025.3565182","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3565182","url":null,"abstract":"This letter presents an analog–digital variable capacitor realized by monolithic integration of barium strontium titanate (BST) ferroelectric material and phase change material (PCM) technologies. The proposed concept enables the creation of tunable components with high performance at microwave and millimeter-wave frequencies, addressing the challenging need for large tuning range and fine resolution, with minimal loss. This letter presents the fabrication and analysis of an analog–digital variable capacitor with a size of <inline-formula> <tex-math>$80 times 120~mu text {m}$ </tex-math></inline-formula>, comprising three BST analog variable capacitor monolithically integrated with three PCM germanium telluride (GeTe) switches. The measurement results for the integrated analog–digital variable capacitor show a tuning ratio of 1:10.8 with an analog resolution over a wide frequency range, while having a quality factor of 12.5 at 30 GHz. To our knowledge, this letter represents the first demonstration of monolithic integration of BST and PCM technologies.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"784-787"},"PeriodicalIF":0.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299279","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":"Ultrawideband CMOS VGA With 2.23 dB NFmin Using Coupled-ML Neutralization","authors":"Jin-Fa Chang","doi":"10.1109/LMWT.2025.3542629","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3542629","url":null,"abstract":"This study reports a low power-dissipation (PD) and low noise-figure (NF) ultrawideband CMOS variable-gain amplifier (VGA). The VGA uses coupled microstrip-line (CML) neutralization, body-floating of transistor M1, and multiple inductive compensations, featuring complementary common-source (CCS) input and common-source (CS) output stages to achieve low PD and NF values and a wide bandwidth (BW). Gain flatness in the ultrawideband VGA is achieved by fitting the coupling between the CML (with the electrical length of a compensated gain-flatness inductor CL). The VGA with a PD of 5.85 mW achieves excellent S21 BW of 32.3 GHz (2.9–35.2 GHz), maximum S21 of 11.9 dB, minimum NF of 2.43 dB, and average NF of 4.11 dB for 5G FR2 and 6G FR3. The input 1-dB compression point of the VGA is −11.5 dBm. Moreover, the VGA with a chip area of 0.356 mm2 attains a decent gain tuning range of 20 dB (−3.8 to 16.2 dB) under 1.35 dB/step for 5G NR band N257.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 5","pages":"609-612"},"PeriodicalIF":0.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949245","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 Ridge WG SSPP Bandpass Filter With Lower Transmission Zero and Extended Upper Stopband","authors":"Jian-Xin Chen;Peng-Xu Zhu;Xu Shi;Wei Qin","doi":"10.1109/LMWT.2025.3548991","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3548991","url":null,"abstract":"This article proposes a novel design method for introducing a lower transmission zero (TZ) in a ridge waveguide (WG) spoof surface plasmon polariton (SSPP) bandpass filter (BPF). Initially, the inverted T-shaped slots are etched on the central ridge to construct the SSPP and then design a wideband BPF, and the upper and lower cutoff frequencies of passband are determined by the SSPP and double gratings (DGs) on both sides of the ridge WG. To improve the rejection roll-off of the lower stopband, a pair of folded slots are etched at both ends of the ridge to form a quarter-wavelength (<inline-formula> <tex-math>$lambda $ </tex-math></inline-formula>/4) resonance for introducing a TZ below the passband without increasing the size. Additionally, the stopband of the proposed SSPP filter can be extended by optimizing the DGs to suppress the higher order modes of the SSPP. To demonstrate this method, a ridge WG BPF was fabricated and measured. The measurement results indicate that the filter possesses favorable frequency selectivity and a wide stopband.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 5","pages":"521-524"},"PeriodicalIF":0.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943967","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 Miniaturized 2.49-GHz Low-Phase-Noise Temperature-Stable SAW Oscillator","authors":"Tangfei Kang;Haoshen Zhu;Jiajian Liang;Bin Jia;Wenquan Che;Quan Xue","doi":"10.1109/LMWT.2025.3546238","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3546238","url":null,"abstract":"In this letter, a 2.49-GHz temperature-stable oscillator is implemented using a temperature-compensated surface acoustic wave (TC-SAW) resonator. The cross-coupled topology is adopted to suppress power supply variations and enhance output swing. The TC-SAW with a temperature-compensated layer is used to improve the temperature stability of the oscillator. Measurement results show that the oscillator achieves a phase noise of 145 dBc/Hz@1 MHz offset with a figure of merit (FoM) of 215 dB. The oscillator consumes a dc power of 0.6 mW under a supply voltage of 1 V. Over a temperature range of <inline-formula> <tex-math>$- 40~^{circ }$ </tex-math></inline-formula>C to <inline-formula> <tex-math>$85~^{circ }$ </tex-math></inline-formula>C, the oscillator’s frequency drift is less than 248 ppm and within 90 ppm over a range of <inline-formula> <tex-math>$- 40~^{circ }$ </tex-math></inline-formula>C to <inline-formula> <tex-math>$65~^{circ }$ </tex-math></inline-formula>C.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 5","pages":"601-604"},"PeriodicalIF":0.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949167","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}
Shuping Li;Donglin Gao;Shaghayegh Vosoughitabar;Chung-Tse Michael Wu
{"title":"Asynchronous Space-Time-Coding Direct Antenna Modulation-Enabled Automated Beam-Scanning Multi-Target Vital Sign Radar Sensing","authors":"Shuping Li;Donglin Gao;Shaghayegh Vosoughitabar;Chung-Tse Michael Wu","doi":"10.1109/LMWT.2025.3566398","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3566398","url":null,"abstract":"This work introduces a new kind of asynchronous space-time-coding (ASTC) direct antenna modulation (DAM)-enabled radar sensor designed for automatic beam-scanning in multi-target vital sign monitoring. Each element of the ASTC array receives a fixed modulation sequence with 2-bit phase ramps and a frequency offset of 8 kHz between adjacent elements, centered at a carrier frequency of 2 GHz. This configuration maintains only the +1st-order harmonic at 2.000008 GHz in the radiation of the ASTC array, facilitating the automatic counterclockwise 1-D half-space beam scanning with a scanning period of <inline-formula> <tex-math>$125~mu $ </tex-math></inline-formula>s. By isolating data points corresponding to each target within each scanning period and applying Fourier analysis, the vital signs of multiple targets can be precisely differentiated and extracted. The proposed radar system combines automatic scanning with fixed settings and a straightforward structure, making it especially suitable for smart home/healthcare applications.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"892-895"},"PeriodicalIF":0.0,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299316","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 Q-Choked Sapphire Sandwiched Resonator for Wideband Measurements of Flat Dielectric Samples","authors":"Wojciech Gwarek;Malgorzata Celuch;Lukasz Nowicki","doi":"10.1109/LMWT.2025.3568534","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3568534","url":null,"abstract":"A novel Q-choked sapphire sandwiched resonator (Q-SSR) is designed, fabricated, and validated for fast and nondestructive testing of materials between upper microwave and lower millimeter-wave (mm-Wave) frequencies. It combines the advantages of the recently proposed Q-choked split cylinder resonator (SCR), where the choke ensures a spectrum of pure TE<sub>0<i>np</i></sub> modes, with the dielectric focusing properties of split-post dielectric resonators (SPDRs), which increase sensitivity and decrease losses in cavity walls. A Q-SSR prototype operating at seven modes in the 12–30 GHz band is applied to reference samples defined in industrial benchmarking initiatives. It produces complex permittivity results in excellent agreement with SCR, SPDR, and Fabry–Perot open resonator (FPOR) techniques, at a competitive effort.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"900-903"},"PeriodicalIF":0.0,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299145","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}
Yizhuo Wu;Yi Zhu;Kun Qian;Qinyu Chen;Anding Zhu;John Gajadharsing;Leo C. N. de Vreede;Chang Gao
{"title":"DeltaDPD: Exploiting Dynamic Temporal Sparsity in Recurrent Neural Networks for Energy-Efficient Wideband Digital Predistortion","authors":"Yizhuo Wu;Yi Zhu;Kun Qian;Qinyu Chen;Anding Zhu;John Gajadharsing;Leo C. N. de Vreede;Chang Gao","doi":"10.1109/LMWT.2025.3565004","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3565004","url":null,"abstract":"Digital predistortion (DPD) is a popular technique to enhance signal quality in wideband radio frequency (RF) power amplifiers (PAs). With increasing bandwidth and data rates, DPD faces significant energy consumption challenges during deployment, contrasting with its efficiency goals. State-of-the-art DPD models rely on recurrent neural networks (RNNs), whose computational complexity hinders system efficiency. This letter introduces DeltaDPD, exploring the dynamic temporal sparsity of input signals and neuronal hidden states in RNNs for energy-efficient DPD, reducing arithmetic operations and memory accesses while preserving satisfactory linearization performance. Applying a TM3.1a 200 MHz-BW 256-QAM OFDM signal to a 3.5-GHz GaN Doherty RF PA, DeltaDPD achieves −50.03 dBc in adjacent channel power ratio (ACPR), −37.22dB in normalized mean square error (NMSE) and −38.52 dB in error vector magnitude (EVM) with 52% temporal sparsity, leading to a <inline-formula> <tex-math>$1.8times $ </tex-math></inline-formula> reduction in estimated inference power. The DeltaDPD code is available at <uri>https://www.opendpd.com</uri>.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"772-775"},"PeriodicalIF":0.0,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299158","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 28/39-GHz Reconfigurable Phased-Array Transmitter Front-End for 5G New Radio in a 65-nm CMOS","authors":"Ruiqi Wang;Yiming Yu;Runyu Liu;Yanpeng Wu;Xin Xie;Zhiguang Chen;Zhinan Jing;Zhixiong Li;Mengqian Geng;Huihua Liu;Chenxi Zhao;Yunqiu Wu;Kai Kang","doi":"10.1109/LMWT.2025.3565703","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3565703","url":null,"abstract":"This article presents a reconfigurable phased-array transmitter (TX) front-end for 5G new radio (NR) in 65-nm CMOS. A reconfigurable up-converter is implemented to support dual-band operation around K-/Ka-bands without increasing LO or intermediate frequency (IF) bandwidth. The circuit moves image signals and spurs outside the passband of the RF channels, achieving a high image rejection ratio (IRR). Measured results show the chip covers both bands of 24–30 GHz and 36–40 GHz with 10–12 GHz LO and 4–6 GHz IF bands, with an IRR over 44 dB. Utilizing a PCB-based Vivaldi antenna array, a four-element phased-array TX front-end system is designed. The beam scanning ranges are ±30° and ±15° at 28 and 39 GHz, respectively. In addition, TX-to-RX wireless communication is demonstrated with the TX system and a K-/Ka-band receiver front-end. The over-the-air (OTA) tests reveal that the data rate is up to 1.2 Gbps/800 Mbps at 27/34.6 GHz over a 1-m distance.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"836-839"},"PeriodicalIF":0.0,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299394","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":"Ka-Band AFSIW Circuit-On-Substrate for Satellite Applications","authors":"Maxime Le Gall;Anthony Ghiotto;Issam Marah","doi":"10.1109/LMWT.2025.3566174","DOIUrl":"https://doi.org/10.1109/LMWT.2025.3566174","url":null,"abstract":"This letter demonstrates a circuit-on-substrate utilizing high-performance passive components based on the air-filled substrate-integrated waveguide (AFSIW) technology. Areceiver module, designed for space applications and operating in the satellite Ka-band frequency range, between 27.5 and 30.2GHz, is introduced. This module integrates both passive and active functions on a single multilayer printed circuit board (PCB). The passive functions include rectangular waveguide (RWG) to AFSIW transitions, circulators, loads, grounded coplanar waveguide (GCPW) to AFSIW transitions for interconnecting surface-mounted low noise amplifiers (LNAs), and a bent 8th-order bandpass filter for compactness. The design of each passive component is introduced, followed by the integration and fabrication of a demonstrator. The circuit’s performance is experimentally validated, with a gain of 35.1 <inline-formula> <tex-math>$pm$ </tex-math></inline-formula> 1.76 dB, a return loss better than 14.7 dB, and a noise figure (NF) of 4.97 <inline-formula> <tex-math>$pm$ </tex-math></inline-formula> 0.64 dB in the frequency band of interest. To the best of the authors’ knowledge, this is the first reported AFSIW circuit-on-substrate.","PeriodicalId":73297,"journal":{"name":"IEEE microwave and wireless technology letters","volume":"35 6","pages":"788-791"},"PeriodicalIF":0.0,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144299280","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}