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Abstract: Presents a listing of the editorial board, board of governors, current staff, committee members, and/or society editors for this issue of the publication. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Abstract: These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Shitao Chen;Qiupeng Yin;Wei Wang;Ming Chen;Weipeng Xuan;Zhixiang Huang;Ming Yu;
Pages: 367 - 370 Abstract: This letter presents an electro-mechanical coupling model for multiphysical field analysis of 3-D microwave film bulk acoustic resonator (FBAR). Microwave FBAR is composed of metal electrode, piezoelectric materials, and substrate. The electrical and mechanical characteristic are analyzed by three equations of piezoelectric constitutive equation, electrostatic field, and Newtonian equations of motion, respectively. Multiphysical coupling model equation is constructed by establishing the relationship between two equations through common physical quantities potential and displacement. In the end, the multiphysical coupling model equation is calculated using the finite-difference time-domain (FDTD) method. Compared with the commercial software (COMSOL), the accuracy of the proposed electro-mechanical method is verified while the computational efficiency and memory requirements are significantly reduced. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Minas Kouroublakis;Nikolaos L. Tsitsas;George Fikioris;
Pages: 371 - 374 Abstract: The method of auxiliary sources with an excitation source (MAS-ES) is a reliable method for determining the eigenvalues $k$ in hollow, 2-D waveguides. This is done using a $k$ -dependent response function $F(k)$ , defined as the mean-square value of the magnitude of the field at a number of random points within the waveguide: plotting $F(k)$ for a fine grid of $k$ yields a response curve with sharp peaks at the positions of the eigenvalues. In this work, it is shown that the eigenvalues can be determined, more simply, by means of the auxiliary currents vector norm (ACVN). We explain our method analytically for the simple problem of the circular waveguide, apply it numerically to more complicated geometries, and compare our results to those of a finite element method (FEM)-based commercial software. We introduce a Hankel-function lookup procedure, which greatly reduces computational times, and discuss the rather peculiar effect of divergence/oscillations of the auxiliary currents. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Jie Li;Lihua Shi;Dedong Ji;Eng Leong Tan;Qi Lei;Yao Ma;Yuzhou Ran;Yicheng Liu;Jianbao Wang;
Pages: 375 - 378 Abstract: The conventional Fourier modal method (FMM) has the problems of large memory requirements and low computational efficiency in analyzing 2-D periodic structures. In this letter, a highly symmetric system matrix formulation of the FMM is presented. The conventional FMM is enhanced by using an improved system matrix incorporated with the Cayley–Hamilton theorem. This makes the FMM more efficient in analyzing 2-D periodic structures. Numerical results agree well with those of published literature and the conventional methods. Simulation results show that, compared with the conventional FMM, the proposed method can significantly reduce the memory requirements and condition number while keeping high accuracy. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Jianan Zhang;Jing Chen;Qianyi Guo;Wei Liu;Feng Feng;Qi-Jun Zhang;
Pages: 379 - 382 Abstract: Neuro-transfer function (neuro-TF) methods are deemed as powerful tools in modeling the electromagnetic (EM) behavior of microwave passive components. Existing neuro-TF methods either endure the issue of “order-changing” or the issue of mismatch of poles/zeros, both calling for specific algorithms to process the data of the transfer function coefficients as a part of model development. This letter proposes a novel neuro-TF method to eliminate the two issues simultaneously by using combined neural networks and model-order reduction (MOR)-based rational transfer functions. In the proposed method, the coefficients of the transfer function are computed by the MOR technique instead of vector fitting. The use of MOR allows the order of the transfer function to remain constant in different regions in the design parameter space, thereby avoiding the issue of “order-changing.” Additionally, the coefficients of the rational transfer function resultant from MOR are naturally sorted according to the order of frequency, which eliminates the issue of mismatch of poles/zeros and subsequently improves modeling accuracy. Compared with existing neuro-TF methods, the proposed method achieves better modeling accuracy for the same geometrical variations. Two microwave examples are utilized to demonstrate the advantages of the proposed method. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Jiacheng Xie;Deshan Tang;Yiyang Shu;Xun Luo;
Pages: 383 - 386 Abstract: In this letter, two types of substrate-integrated defected ground structure (SIDGS) resonators (i.e., loaded-stub and C-shape resonators) are proposed for the ultra-wideband (UWB) bandpass filter (BPF) design. Coupled SIDGS resonators can generate four transmission poles to achieve the UWB response with low insertion loss in a compact size. Besides, the spurious cancellation with a broad stopband is achieved by mutual suppression of separated harmonics from the SIDGS resonators. In addition, the lowpass units (LPUs) embedded in the microstrip feed-lines are utilized to further improve the BPF stopband rejection. To verify the mechanism, a compact BPF operating at 6.85 GHz (i.e., the passband center frequency $f_{0}$ ) with 0.6-dB insertion loss and 3-dB fractional bandwidth (FBW) of 114% is implemented and fabricated. The measured stopband extends to $9.7f_{0}$ with a rejection level more than 26 dB. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Gang Zhang;Jian Zheng;Xiu Yin Zhang;Hua Yang;Wanchun Tang;Jiquan Yang;
Pages: 387 - 390 Abstract: A new dual-band balanced to unbalanced (BTU) multilayer filtering magic-T (FMT) based on square substrate integrated waveguide (SIW) cavity is proposed in this letter. Degenerate TE201 and TE203 modes are exploited to realize the requested dual-band filtering responses and in-/out-of-phase characteristic. The requested differential-mode (DM) transmission, common-mode (CM) suppression, and port-to-port isolation can be obtained by appropriately placing the input–output ports and coupling slots. Multiple transmission zeros (TZs) are introduced to improve frequency selectivity, and the center frequencies (CFs) can be flexibly controlled to some extent. For validation, a prototype dual-band BTU FMT operating at 11.6 and 19.1 GHz is fabricated and measured. It can be obtained that the simulated results are in good agreement with the measured ones. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Jongheun Lee;Juseop Lee;
Pages: 391 - 394 Abstract: An accurate method to implement a bandpass-domain coupled-line Foster section is presented. Two types of practical coupled-line structures are presented and closed-form equations for their design parameters are given in terms of lowpass prototype parameters, reference impedance, and fractional bandwidth so that one can readily use them in various filter designs. The design process of a bandpass filter using Foster sections is described via an example. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Liguo Zhou;Zhihe Long;Quanyuan Feng;Qiuyan Jin;Yongwei Li;
Pages: 395 - 398 Abstract: A channel-continuous triplexer (CCT) with multiple transmission zeros (TZs) is designed and processed by cascading the high-pass filter (HPF) and low-pass filter (LPF) through the matching branches. The CCT is realized based on the substrate integrated suspended line (SISL) technology. The out-of-band suppression (OBS) and roll-off rate (ROR) of CCT are improved by the TZs introduced by cross-coupling lines between the nonadjacent branches in the HPFs and high-low impedance microstrip line T junction in LPFs. The experimental results show that CCT covers 4–7 GHz by three continuous bandwidth-identical passbands with the fractional bandwidths (FBWs) of 22.2%, 18.1%, and 15.3%, respectively. The insertion loss within three passbands is less than 1.7 dB, the out-of-band rejection is more than 50 dB, and the ROR is greater than 200 dB/GHz. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Zhihao Lv;Zhiwei Xu;Ruirui Dang;Chunyi Song;Xiaopeng Yu;
Pages: 399 - 402 Abstract: A compact gate-width scalable model of dual-gate gallium arsenide pseudo high electron mobility transistors (GaAs pHEMTs) is proposed. We derive the model based on analytical formulation and represent it with a simplified circuit containing only eight elements. Compared with the dual-gate model using two separate devices, this modeling method is much simpler in characterization and can extract intrinsic parameters directly from two-port measurements. Extrinsic parameters are extracted by de-embedding method evolved from the conventional open-short method. Devices with different gate widths and numbers of finger are modeled to verify the scaling effect. The simulated results based on the proposed model agree with the measured results well up to 40 GHz for $0.25~mu text{m}$ GaAs pHEMT devices. In addition, a large-signal model is built based on the proposed dual-gate model. A 2 GHz power amplifier was realized to illustrate the suitability of the proposed model for circuit design. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Shujiang Ji;Yizhuo Wang;Yuxiao Zhao;Haoyuan Gao;Yiyun Mao;Xinyi Lin;Sijia Lai;Hao Min;Na Yan;
Pages: 403 - 405 Abstract: A sub-sampling PLL (SSPLL) employing an adaptive frequency-locked loop (FLL) without static power consumption is proposed in this letter. A new unlock detection mechanism and a configurable PFD are realized in the adaptive FLL. With the new unlock detection mechanism, while the FLL that contains phase detector, divider, and charge pump dissipates no power during the locked steady state, it automatically starts when external interferences disturb the locked state. The optimized dead zone in the configurable PFD ensures a rapid relocking operation. Based on the proposed adaptive FLL, the 2.4 GHz SSPLL is fabricated in a 40-nm CMOS process. It achieves −128.5 dBc/Hz at 1 MHz offset frequency and the rms jitter is 103.58 fs integrated from 10 k to 10 MHz. It consumes 1.55 mW at 1 V supply and achieves −257.8 dB FOM. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Daniel Reiter;Hao Li;Badou Sene;Nils Pohl;
Pages: 406 - 409 Abstract: A passive mixer-first receiver architecture operating at a frequency range between 70 and 86 GHz, together with a two-stage LO buffer and a low noise IF amplifier, is presented and designed in a 28-nm bulk CMOS technology. The receiver achieves a single-sideband noise figure (SSB NF) of less than 10 dB for IF frequencies above 400 kHz with a minimum of 9 dB above 1 MHz. The implemented chip features a voltage gain of about 14 dB and a 1-dB compression point of −5 dBm. The receiver core occupies an area of $mathbf {0.09}~{text {mm}^{2}}$ and consumes 55 mA from a 1.8-V power supply including all ON-chip biasing circuits. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Fatemeh Akbar;Amir Mortazawi;
Pages: 410 - 413 Abstract: This letter presents a new circuit topology for a vector sum phase shifter where the amplitudes and phases of ${I}$ and $Q $ are simultaneously varied using a single analog control signal. The simultaneous adjustment of amplitudes and phases of ${I}$ and ${Q}$ allows for the vector sum’s large phase tuning while maintaining its amplitude. Moreover, various functions of vector summation are all performed in a single stage, minimizing the chip real estate and power consumption. The maximum range of analog phase tuning with a constant amplitude is theoretically 180°, but in practice, it is limited by the tuning range of the utilized varactors. To achieve a large phase tuning range given varactors with limited tunability, digital control has been added to allow for coarse tuning of the phase. The utilized approach for coarse phase tuning preserves the chip area and power consumption but causes amplitude variation. The phase shifter performance is verified by simulations and measurements. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Mingming Ma;Fei You;Guanxiong You;Ce Shen;Zehua Xiao;Wenqi Wu;Yin Chen;Yu Wang;Hongqi Tao;Ting Qian;Runnan Guo;Bin Zhang;Tao Wu;Songbai He;
Pages: 414 - 417 Abstract: This letter presents a fully integrated dual power mode Doherty power amplifier (PA) in the Nanjing Electronic Devices Institute (NEDI) 250-nm GaN process. Due to the advantages of high power (HP) and gain, the cascode architecture is introduced to both carrier and peaking PAs. To the author’s best knowledge, this is the first time cascode architecture is applied in GaN process for sub-6 GHz Doherty PA design. The equivalent parasitic network and interstage impedance matching network of cascode transistors are constructed and extracted within the frequency range of 1–15 GHz. High efficiency voltage–current waveform at the current generator plane of carrier PA is achieved. The gate and drain bias of the common gate transistor are adjusted to attain low power (LP)/HP mode. A Doherty PA prototype operating in 5G NR FR1 n78 is presented with a saturated power of 36.5–37.2 dBm, a peaking power added efficiency (PAE) of 49.6%–52.0%, a 6-dB back-off PAE of 34.4%–39.6%, and a gain of 12.2–12.9 dB for LP mode. The realized high-gain saturated power is 39.8–40.5 dBm with a relatively HP density of 3.96 W/mm, a peaking PAE of 42.5%–47.7%, a 6-dB back-off PAE of 32.0%–37.8%, and a gain of 16.0–16.4 dB for HP mode. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Sung-Hyun Pang;Youngwoon Kim;Tae-Yeoul Yun;
Pages: 418 - 421 Abstract: This letter presents a 2.4-GHz high-gain, low-power, and low-noise complementary metal–oxide–semiconductor (CMOS) mixer using a current-reused bleeding amplifier. To reduce flicker noise, a resonant inductor and a current bleeding circuit are conventionally adopted, which also increases the conversion gain. In this letter, the conventional current bleeding circuit is modified to a current-reused bleeding amplifier to further increase the conversion gain, which also further decreases noise while consuming the same current, compared to the conventional circuit. Measurement results show a conversion gain of 14.64 dB, a noise figure of 9.17 dB at 10 kHz and 7.23 dB at 100 MHz, and an input third-order intercept point (IIP3) of −15.89 dBm. The proposed mixer has a power consumption of 3.82 mW from a 1.5-V supply voltage. It was fabricated by using a 65-nm CMOS process. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Gaoya Dong;Xiaolong Yang;Yunnan Fang;Manos M. Tentzeris;
Pages: 422 - 425 Abstract: A filtering push–pull power amplifier (PPPA) is presented based on the multifunctional impedance matching network (MIMN), which is constructed by coupled lines and open-circuited transmission lines. Due to the symmetry of designed MIMN, the even-and odd-mode method is employed to analyze the operating mechanisms, which reveal that designed MIMN can achieve high common mode suppression under the even-mode excitation, while provide good impedance transformation and filtering response under the odd-mode excitation. Finally, a filtering PPPA based on the MIMN is designed as well as measured, and the measured operating frequencies are ranging from 1.85 to 2.03 GHz. The measured maximum gain and peak power-added efficiency are 13.9 dB and 57.8%, while the measured upper stopband extends to 4.1f0 with the suppression level of 20 dB. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Sheng-Lyang Jang;Hung-Wei Lai;Jiun-Yu Sung;
Pages: 426 - 429 Abstract: This letter proposes a CMOS divide-by-16 injection-locked frequency divider (ILFD) with a divide-by-4 ring-oscillator frequency divider (FD) stacked on a capacitive cross-coupled LC divide-by-4 ILFD. The divide-by-16 ILFD in the Taiwan Semiconductor Manufacturing Company, Limited (TSMC) $0.18~mu text{m}$ 1P6M CMOS process has a locking range from 10.76 to 12.6 GHz at the power consumption of 12.5 mW and an external injected signal power $P_{mathrm {inj}}$ of 0 dBm. The varactor-less divide-by-16 ILFD uses the ring-oscillator FD with wide locking range to track the input frequency from the LC ILFD output, and occupies an area of $1.2times1.198$ mm2. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Fabian Thome;Frank Schäfer;Sener Türk;Pavel Yagoubov;Arnulf Leuther;
Pages: 430 - 433 Abstract: This letter presents a 67–116-GHz low-noise amplifier (LNA) module with state-of-the-art cryogenic noise performance. The LNA is based on a monolithic microwave integrated circuit (MMIC) that is fabricated in a 50-nm metamorphic high-electron-mobility transistor (mHEMT) technology. The MMIC is packaged in a WR10 waveguide split-block housing and uses fused silica ${E}$ -plane microstrip-to-waveguide transitions. For a 67–116-GHz bandwidth, the amplifier exhibits average noise temperatures ( ${T}~_{{text {e}}}$ ) at 15 and 300 K of 21.4 and 194 K, respectively. A minimum ${T}~_{{text {e}}}$ of 13.6 K is achieved at 72.2 GHz. To the best of the authors’ knowledge, this LNA demonstrates a new low-noise benchmark for room temperature and cryogenic noise temperatures in the extended ${W}$ -band frequency range. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Zhao Xing;Huihua Liu;Yunqiu Wu;Chenxi Zhao;Yiming Yu;Kai Kang;
Pages: 434 - 436 Abstract: A voltage-controlled oscillator (VCO) based on a current-reuse (CR) topology is proposed. By inversely coupling two CR VCOs through tank inductors, the proposed VCO inherits the good phase noise performance of CR VCO, and meanwhile can realize differential outputs and alleviate the disturbance of VCO to the power supply and ground. Also, the proposed VCO achieves a phase noise improvement due to the electro-magnetic coupling of a transformer. Fabricated in the 180-nm CMOS process, the core circuit of the proposed VCO occupies an area of $0.4times0.32$ mm2. Under a supply voltage of 1.2 V, the measured tuning range is 2.88–3.61 GHz (22.5%). The phase noise at 1-MHz offset varies between −126.7 and −123 dBc/Hz among the tuning range. The figure of merit (FoM) is in the range of 188.1–190.7 dBc, at 1-MHz offset. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Rui Zhang;Zhe Chen;Zekun Li;Debin Hou;Jixin Chen;Wei Hong;
Pages: 437 - 440 Abstract: A wide tuning range, low-phase-noise SiGe BiCMOS LC voltage-controlled oscillator (VCO) covering both the Ku- and Ka-bands is presented in this letter. The proposed VCO using a cross-coupled topology creates the fundamental harmonic from 14.35 to 17.86 GHz and the second harmonic, which is drawn from the common-mode point through a matched buffer, covering from 28.7 to 35.72 GHz. A transformer-coupled tank, which takes advantage of tank parasitics to create harmonic resonances, is used to reduce the phase noise (PN). The 5-bit binary-weighted capacitor bank is connected to the transformer secondary to create a wide tuning range, which is measured from 14.35 to 17.86 GHz (21.1%) and 28.7 to 35.72 GHz. Brilliant PN of −115.5 and −109 dBc/Hz at 1-MHz offset is measured at 14.53- and 29.1-GHz carrier frequencies individually. The proposed VCO with an extra output of the second harmonic exhibits little PN deterioration. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Tomasz Karpisz;Bartlomiej Salski;Pawel Kopyt;Jerzy Krupka;Marcin Wojciechowski;
Pages: 441 - 443 Abstract: Measurement results of uniaxially anisotropic materials performed with the aid of a plano-concave Fabry–Perot open resonator in the 20–50 GHz frequency range are presented and discussed in this letter. It is shown that a linear polarization of Gaussian modes applied in the characterization allows extracting in-plane complex permittivity of such materials as crystals and foils in a single measurement cycle. It is also shown that dielectric losses exhibit anisotropy, which can be quite significant, like in the sapphire, or relatively small, like in polymer foils. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Jianxing Li;Jie-Kai Lin;Xinyue Song;Sen Yan;Kai-Da Xu;Xiu Yin Zhang;
Pages: 444 - 447 Abstract: This letter presents a novel efficiency-enhanced wireless power transfer (WPT) system operating at 13.56-MHz ISM band. Dual sub-resonators at both transmitting and receiving ends are employed to introduce multiple coupling paths and boost system efficiency. The closed-form equations are derived to verify the advantages of the proposed scheme. A prototype of the WPT system is implemented using the printed circuit board (PCB) technique, which features easy fabrication and small volume. The dual sub-resonators are fabricated on both sides of the PCB with a total dimension of 15 $times15$ cm2. Experimental and simulated results which exhibit a good agreement are presented and discussed. An efficiency of 90% is achieved at 15 cm, implying an enhancement of approximately 7% as compared with the conventional WPT schemes. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Muhibur Rahman;Ke Wu;
Pages: 448 - 451 Abstract: This letter presents a reconfigurable picosecond (ps) pulse generator (PG) having Gaussian and monocycle pulse shapes for impulse radar ultrawideband (IR-UWB) applications. A mixed step recovery diode (SRD) topology is used in combination with a non-linear transmission line (NLTL) and pulse-shaping circuit to realize the PG. The pulse-shaping network comprises an RC differentiator embedded with a single p-i-n diode to provide two different switchable states. This PG is capable of directly switching from a Gaussian to a monocycle pulse without resorting to the increase in pulsewidth twice of the original Gaussian pulse as deployed in the previous reconfigurable PGs. The PG based on the proposed technique has a pulse duration of almost 70 ps with a promising ringing level in both cases (Gaussian and monocycle). Moreover, not only is the implementation of this technique easy, but it can also modify the pulse into other important shapes, such as the doublet and higher order Gaussian pulses. The proposed reconfigurable PG is measured in both cases, and the results are presented in each case. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Yang Chen;Taixia Shi;
Pages: 452 - 455 Abstract: A simplified Doppler frequency shift (DFS) measurement approach based on Serrodyne optical frequency translation is reported. A sawtooth wave with high amplitude is sent to one phase modulation arm of a Mach–Zehnder modulator in conjunction with the transmitted signal to implement the Serrodyne optical frequency translation, as well as the optical phase modulation of the transmitted signal on the frequency-shifted optical carrier. The echo signal is applied to the other arm of the modulator. The lower first-order optical sidebands from the modulator are selected by an optical bandpass filter and detected in a photodetector. By measuring the frequency of the output low-frequency signal, the value and direction of the DFS can be determined. DFS from −100 to 100 kHz is measured for 6- to 17-GHz microwave signals with a measurement error of ±0.03 Hz and a measurement stability of ±0.015 Hz in 30 min when a 500-kHz sawtooth wave is used. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Fading Zhao;Gang Li;Daniele Inserra;Zhong Huang;Chengwei Xian;Bing Chen;Pengju Kuang;Guangjun Wen;
Pages: 456 - 459 Abstract: This letter discusses a nonlinear Schottky diode modeling method for microwave rectifier design and fast optimal diode selection. Diode power losses due to the diode series resistor, junction capacitor, built-in potential, and breakdown voltage are analyzed based on the current–voltage diode characteristic curve which can accurately predict the maximum achievable power conversion efficiency (PCE) of the rectifier circuit in both low and high input power regions. Closed-form equations are then derived to predict the PCE of a given diode at a specific working condition (input power, frequency, and load value), which can be a very useful tool for fast optimal diode selection. The proposed model has been verified both numerically and experimentally for different Schottky diodes and working frequencies, finding very good correspondence with circuit simulation results and confirming the reliability of the discussed method. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
A. M. Bobreshov;A. S. Zhabin;A. D. Ryazantsev;V. A. Stepkin;G. K. Uskov;
Pages: 460 - 462 Abstract: The amplitude and width of the ultrashort pulses depend on the performance of the generator’s electronic elements. The usage of step recovery diodes (SRDs) with picosecond switching time can lead to a significant increase in device cost. In this letter, nonlinear transmission line (NLTL) was built and tested using commercial-off-the-shelf components to improve the performance of the generator that is based on inexpensive diodes. The method to control output pulse duration by keeping the constant amplitude was proposed. Measurement results show that generated ultrashort pulse can be compressed using NLTLs and the output amplitude of the compressed pulse is 54 V and the duration is 240 ps. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Jiayan Wu;Songbai He;Jun Peng;Peng Hao;Fei You;
Pages: 463 - 466 Abstract: In this letter, we present a magnitude scaling-based power scalable model for dynamic power transmission. Benefiting from the regularity of power amplifier’s (PA’s) behavior at different power levels, the proposed power adaptive model only needs to update the model parameters in the low magnitude during digital predistortion (DPD). A power factor is applied to scale the magnitude of the input signal, and a piecewise model is used to realize the segmented extraction of the parameters. Experiments carried out on a gallium nitride (GaN) PA show that the proposed method can reduce the model coefficients needed update by at least 50% with the comparable linearization performance. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Wenhui Cao;Siqi Wang;Thomas Eriksson;
Pages: 467 - 470 Abstract: This letter investigates digital predistortion (DPD) models for concurrent multiband (MB) transmitters, considering intermodulations (IMDs) fully and partially overlapping with in-band carriers. In order to mitigate the issue of increasing complexity of IMD terms construction, a novel prefrequency shift MB DPD technique is proposed to translate the baseband input signals in frequency by carrier frequencies. Theoretical analysis is provided to justify the prefrequency shift technique. Experimental measurements have been carried out with a quad-band signal to validate the effectiveness of the proposed technique. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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Authors:
Pavel V. Priputnev;Ilya V. Romanchenko;Sergei N. Maltsev;Vladimir Yu Konev;Vladimir P. Tarakanov;
Pages: 471 - 474 Abstract: This article presents a work on development of a high-power radio pulse generator, which is a gyromagnetic nonlinear transmission line (GNLTL) in which periodically placed NiZn ferrites are saturated by an axial magnetic field produced by permanent magnets periodically placed inside the transmission line. Structurally, the line is a corrugated coaxial waveguide with permanent NdFeB magnets placed inside the inner conductor of the line. The transmission line geometry was optimized using numerical simulation by finite-difference time domain (FDTD) method. The excitation of high-frequency oscillations in the developed transmission line at central frequency of 1 GHz and above is shown experimentally using ferrite rings with 45 and 28 mm outer and inner diameters. The maximum peak power of microwave oscillations obtained in the experiments is 110 MW at the central frequency 1.3 GHz. The obtained RF power is comparable to that of more common GNLTL with continuous filling by ferrite rings having the same transverse size. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
Please help us test our new pre-print finding feature by giving the pre-print link a rating. A 5 star rating indicates the linked pre-print has the exact same content as the published article.
Authors:
Yucheng Yu;Jialin Cai;Xiao-Wei Zhu;Peng Chen;Chao Yu;
Pages: 475 - 478 Abstract: The future intelligent communication systems will dynamically adjust the transmitted signal according to the radio environment and human behavior, which will lead to the rapid change of the characteristics of power amplifier (PA) and bring new challenges for digital predistortion (DPD). In this letter, a novel self-sensing DPD (SS-DPD) technique is proposed to linearize PA driven by fast time-varied signals. By automatically sensing the features of input signal and integrating them into the neural network, the proposed model is capable of linearizing the PA operated in such time-varied scenarios without updating DPD coefficients. Furthermore, the polynomial basis functions are embedded into neural network to reduce the complexity. Experimental results on a Doherty PA driven by the fast time-varied signal show that the proposed method can achieve good performance constantly with low complexity. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
Please help us test our new pre-print finding feature by giving the pre-print link a rating. A 5 star rating indicates the linked pre-print has the exact same content as the published article.
Authors:
Myun-Joo Park;
Pages: 479 - 481 Abstract: It is shown that the two-section branch-line coupler proposed in Liu and Lin (2021) corresponds to the cascade connection of two conventional couplers. The design of the two-section coupler can be reduced to that of a conventional single-section branch-line coupler. The wide-range phase-differences of the two-section couplers become ineffective toward larger power-dividing ratios and the two-section couplers have a much-reduced range of power-dividing ratios as compared with the conventional single-section couplers. PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
Please help us test our new pre-print finding feature by giving the pre-print link a rating. A 5 star rating indicates the linked pre-print has the exact same content as the published article.
Authors:
J. Zhang;J. Chen;Q. Guo;W. Liu;F. Feng;Q. J. Zhang;
Pages: 482 - 482 Abstract: In the above article [1], the funding information should have been included as: PubDate:
May 2022
Issue No:Vol. 32, No. 5 (2022)
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