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Wen Wu - IEEE Xplore Author Profile

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To address the stringent requirements for massive connectivity and high information freshness in the Industrial Internet of Things (IIoT), the non-orthogonal multiple access (NOMA) and intelligent reflecting surface (IRS) are introduced as a promising solution. In this paper, we investigate a downlink IRS-assisted NOMA-based short packet communication system, where the age of information (AoI) is ...Show More
A vector-summing phase shifter (VSPS) with gm-boosted structure followed by a variable gain amplifier (VGA) with low phase variation, i.e., PS-VGA, was demonstrated at 27–31 GHz. Triple-coupling transformer (TCT) technique was employed in VSPS for gm boosting and noise reduction. A novel phase compensation technique of main-path inductor compensation (MPIC) was proposed in VGA to greatly suppress ...Show More
rgb0.00,0.00,0.00In this paper, we investigate an intelligent reflecting surface (IRS) assisted sensor system, where the average age of information (AoI) is derived to characterize the information freshness of short packets. Although the IRS can enhance the beamforming gain which improves the AoI performance, it also introduces higher channel estimation overhead which impairs the AoI performance. ...Show More
A packaged quasi-circulator (QC) with low noise, low insertion loss (IL), high isolation, and ease of manufacturing is proposed in this letter. The proposed QC is constructed by two couplers, three connecting transmission lines (TLs), and a common-emitter amplifier. High isolation between transmitter (TX) and receiver (RX) ports can be obtained using two-way signal cancellation by designing the am...Show More
Due to their high maneuverability, flexible deployment, and low cost, uncrewed aerial vehicles (UAVs) are expected to play a pivotal role in not only communication but also sensing. Especially by exploiting the ultrawide bandwidth of terahertz (THz) bands, integrated sensing and communication (ISAC)-empowered UAVs have been a promising technology of 6G space–air–ground integrated networks. In this...Show More
In this paper, a novel wideband multibeam array fed by a non-coplanar substrate integrated coaxial line (SICL) Butler matrix is presented for millimeter-wave (mmW) applications. The presented Butler matrix consists of SICL non-coplanar couplers, crossovers, and phase shifters, whose inner signal strips are printed on adjacent layers. Considering the weak coupling between circuits on adjacent layer...Show More
A Ka-band high-efficiency 8 × 8 dual-polarized patch array antenna is presented. With air as primary transmission medium, the double-sided even-mode air suspended line (ASL) has low attenuation constant, thereby realizing low-loss transmission. A 2 × 4 sub-array fed by this low-loss line through coupling slots is proposed at 35 GHz. By extending the sub-array, an 8 × 8 dual-polarized array is fina...Show More
The Butler matrix is a well-known beamforming network (BFN) for antenna arrays that can achieve multiorthogonal beams with the number of ports typically limited to $2^{n}$ . Current methods to achieve non- $2^{n}$ ports are mainly based on additional power distribution networks or modifications of the directional coupler, resulting in larger sizes and higher insertion loss. This article presents...Show More
Energy efficiency (EE) has become a key design metric for the sustainable development of future wireless communications. Dynamic metasurface antennas (DMAs), with their compact size and low power consumption, are considered a promising solution for improving EE. In this letter, we investigate the energy-efficient beamforming design for downlink multiple-input single-output communication systems, w...Show More
In this letter, a multifunctional reconfigurable metamaterial (MRMM), featuring three operating states is introduced based on the multi-scale integration of hierarchical microchannel configuration and liquid metal (LM) regulation strategy. The MRMM can flexibly switch among full-band transmission from 8 GHz to 15 GHz with an insertion loss (IL) of 1 dB, second-order bandpass from 11.64 GHz to 13.7...Show More
In this article, a kind of miniaturized broadband balun is proposed and designed with high operating frequency and low insertion loss based on the low-cost self-packaged air-filled suspended line and its specialized extended filter theory. The filter theory is extended as follows. First, through making clear the out-of-phase outputs, impedance property of half-wavelength resonator, and miniaturize...Show More
Phased array (PA) has received considerable attention as a representative multiantenna technique due to its inherent advantages of superior directionality, spatial multiplexing capabilities, and robust anti-jamming characteristics. However, PA suffers from relatively high hardware complexity and power consumption. As a low-complexity array technology with excellent beamforming capability, time mod...Show More
A wideband active single-sideband time modulator (STM) is proposed in this paper, which achieves high-resolution frequency-independent phase shifting performance through high-precision time delay, eliminating the need for calibrations. The analysis starts with N-step time modulation sequences for the active STM, followed by discussions on enhancing the sideband suppression ratio (SSR) and the effe...Show More
Integrated sensing and massive multiple-input-multiple-output (MIMO) communication (mMIMO-ISAC) at terahertz (THz) bands can provide vast spatial degrees of freedom and abundant bandwidth resources. However, the employment of a massive number of antennas will pose prominent challenges to both target sensing and channel training in THz-mMIMO-ISAC. In this article, our goal is to integrate the targe...Show More
The performance of wireless communication systems has been improved with the recent advances in array antenna technology. In this paper, we propose a scheme to improve the age of information (AoI) for covert communication with multi-antenna technique (MAT). Specifically, we first propose the transmitter structures and the corresponding beamforming methods for the considered model. Subsequently, th...Show More
A Ku-Band high-efficiency monolithic microwave integrated circuit high-power amplifier based on a commercially available 0.25-µm GaN technology is presented. A three-stage topology is employed in this design to enhance both gain and efficiency. The simulated results demonstrate that the proposed HPA chip, occupying an area of $4.1\times 3\text{mm}^{2}$, features an average output power of 45.2 dBm...Show More
In this work, based on the scheme using the antenna array back-loaded radio frequency circuit (BLRFC) to realize circuit-level manipulation, a novel design of amplitude/phase-manipulation metasurface (A/PMMS) is proposed. The BLRFC has been used to manipulate transmissive electromagnetic (EM) waves by loading control circuits between the grounds of two antenna arrays. Based on the proposed A/PMMS,...Show More
This letter proposes a novel single-sideband time modulator (STM) that uses a periodically controlled 4-bit active vector modulator with regularly controlled gate widths. Timing sequences for control bits are generated from a single digital sequence using a $\div 16$ frequency divider. By precisely delaying the single digital sequence, the proposed active STM achieves high-precision and frequenc...Show More
This paper presents an independent controllable multi-beam technology based on time-modulated array (TMA). Stepped waveform generated by in-phase/quadratue (I/Q) time modulation with digital attenuators is applied to present flexible time-modulated signals. It adjusts the time delay of each sideband independently to control the direction of the corresponding beams. Simulated radiation patterns at ...Show More
In this letter, a broadband filtering power divider (FPD) based on a quarter circular/cambered substrate integrated waveguide (QCCSIW) cavity and microstrip line (MSL) resonators is proposed. First, a second-order bandpass filter (BPF) is designed based on the arc-shaped coupling of the QCCSIW. Second, a pair of quarter-wavelength ( $\lambda $ /4) MSL resonators are integrated into the QCCSIW cavi...Show More
The interrupted-sampling repeater jamming (ISRJ) based on digital radio frequency memory (DRFM) significantly restricts radar target detection. In this paper, we propose an electronic counter-countermeasures (ECCM) scheme using orthogonal frequency division multiplexing with Index Modulation (OFDM-IM) as the radar signal to against deception jamming. Utilizing the pulse diversity technology of OFD...Show More
In this letter, a dual-band transmission-reflection-integrated coding metasurface is proposed. It possesses frequency- and polarization-dependent properties and is capable of effectively generating and controlling splitting beam patterns. The multilayered coding unit mainly consists of a multistrip layer, a double arrow layer, and metal gratings along two ortho- gonal directions. Unlike individual...Show More
In this letter, we investigate the channel estimation problem for MIMO wireless communication systems with movable antennas (MAs) at both the transmitter (Tx) and receiver (Rx). To achieve high channel estimation accuracy with low pilot training overhead, we propose a tensor decomposition-based method for estimating the parameters of multi-path channel components, thereby reconstructing the wirele...Show More
A wideband, low-profile stub-loaded dipole array fed by substrate-integrated coaxial line (SICL) is proposed for millimeter-wave (mmW) applications. The antenna element consists of a stub-loaded dipole with opposite arm orientations, which suppresses the undesirable cross-polarized radiation. Particularly, two grounded stubs are loaded on the two sides of the dipole radiator, not just for suppress...Show More
This letter presents a wide angle and high selective bandpass frequency selective surface (FSS) based on meandering square slot resonators. The proposed FSS mainly consists of five square annular slots deployed in a three-layer structure. To elucidate the operating principle, an equivalent circuit model is constructed and analyzed. The results indicate the generation of a passband with three trans...Show More