Current Issue

2024 Vol. 33, No. 2

Challenges and Opportunities of Sub-6 GHz Integrated Sensing and Communications for 5G-Advanced and Beyond
HUANG Yuhong
2024, 33(2): 323-325. doi: 10.23919/cje.2023.00.251
Abstract(244) HTML (122) PDF(52)
The integrated sensing and communications (ISAC) technology has been perceived as a key feature of 5G-Advanced and beyond mobile communication networks. Compared with sensing in millimeter-wave bands, sensing at sub-6 GHz band is an exceptional incentive to promote the industrialization process of ISAC due to its incomparable advantages in industrial development, especially for intelligent transportation and smart drone networks. This paper elaborates on the top challenges of sub-6 GHz ISAC technologies, as well as the potential solutions to improve the sensing capability.
Low Loss and Low EMI Noise Trench IGBT with Shallow Emitter Trench Controlled P-Type Dummy Region
ZHANG Jinping, LI Xiaofeng, ZHU Rongrong, WANG Kang, ZHANG Bo
2024, 33(2): 326-335. doi: 10.23919/cje.2022.00.080
Abstract(288) HTML (142) PDF(59)
A novel trench insulated gate bipolar transistor (TIGBT) with a shallow emitter trench controlled P-type dummy region (STCP-TIGBT) is proposed. Compared with the conventional TIGBT with floating P-type dummy region (CFP-TIGBT) and TIGBT with floating P-type dummy region and normally on hole path (HFP-TIGBT), the proposed STCP structure not only speeds up the extraction of excessive holes in the turn-off process but also reduces the Miller plateau charge (Qgc). Therefore, both the power loss and electromagnetic interference (EMI) noise are significantly reduced. Simulation results show that the Qgc of the proposed device is only 501 nC/cm2, which is reduced by 58.5% and 26.4% when compared to the CFP-TIGBT and HFP-TIGBT, respectively. At same on-state voltage drop (Vceon) of 1.02 V, the turn-off loss (Eoff) of the proposed device is 13.49 mJ/cm2, which is 64.6% and 67.6% less than those of the CFP-TIGBT and HFP-TIGBT, respectively. Moreover, the reverse recovery dVak/dt of the freewheeling diode at same turn-on loss (Eon) of 31.8 mJ/cm2 for the proposed STCP-TIGBT is only 2.15 kV/μs, which is reduced by 91.3% and 57.2% when compared to 24.69 kV/μs and 5.02 kV/μs for the CFP-TIGBT and HFP-TIGBT, respectively. The reduced dV/dt significantly suppresses the electromagnetic interference noise generated by the proposed device.
Design of High Performance MXene/Oxide Structure Memristors for Image Recognition Applications
LIAN Xiaojuan, SHI Yuelin, SHEN Xinyi, WAN Xiang, CAI Zhikuang, WANG Lei
2024, 33(2): 336-345. doi: 10.23919/cje.2022.00.125
Abstract(372) HTML (186) PDF(52)
Recent popularity to realize image recognition by memristor-based neural network hardware systems has been witnessed owing to their similarities to neurons and synapses. However, the stochastic formation of conductive filaments inside the oxide memristor devices inevitably makes them face some drawbacks, represented by relatively higher power consumption and severer resistance switching variability. In this work, we design and fabricate the Ag/MXene (Ti3C2)/SiO2/Pt memristor after considering the stronger interactions between Ti3C2 and Ag ions, which lead to a Ti3C2/SiO2 structure memristor owning to much lower “SET” voltage and smaller resistance switching fluctuation than pure SiO2 memristor. Furthermore, the conductances of the Ag/Ti3C2/SiO2/Pt memristor have been modulated by changing the number of the applied programming pulse, and two typical biological behaviors, i.e., long-term potentiation and long-term depression, have been achieved. Finally, device conductances are introduced into an integrated device-to-algorithm framework as synaptic weights, by which the MNIST hand-written digits are recognized with accuracy up to 77.39%.
A Bus Planning Algorithm for FPC Design in Complex Scenarios
WU Haoying, ZOU Sizhan, XU Ning, XIANG Shixu, LIU Mingyu
2024, 33(2): 346-352. doi: 10.23919/cje.2022.00.399
Abstract(450) HTML (225) PDF(50)
Flexible printed circuit (FPC) design in complex scenarios has a list of pin concentration areas, which lead to extremely congested intersection regions while connecting the pins. Currently, it is challenging to explore the routability and to find topologically non-crossing and routable paths manually for the nets timely. The existing bus planning methods cannot offer optimal solutions concerning the special resource distribution of the FPC design. To investigate an effective way to shorten the routing time of FPC and achieve enhanced performance, a bus planning algorithm is proposed to tackle complex area connection problems. On the basis of the pin location information, the routing space is partitioned and generally represented as an undirected graph, and the topological non-crossing relationship between different regions is obtained using the dynamic pin sequence. Considering the routability and electrical constraints, a heuristic algorithm is proposed to search the optimal location of the crossing point on the region boundary. Experimental results on industrial cases show that the proposed algorithm realize better performance in terms of count and routability in comparison with numerous selected state-of-the-art router and methods.
A Single-Event-Transient Hardened Phase Locked Loop for Clock and Data Recovery
YUAN Hengzhou, LIANG Bin, SANG Hao, XU Weixia, GUO Yang, CHEN Xi
2024, 33(2): 353-361. doi: 10.23919/cje.2022.00.017
Abstract(183) HTML (89) PDF(27)
A radiation-hardened phase-locked loop is proposed for phase interpolator clock and data recovery purposes. A sensitive node-compressed charge pump and multi-node cross coupling voltage-controlled oscillators are proposed in this phase-locked loop with the goal of achieving good jitter performance and improving anti-SET (SET, single-event transient) capability. The root mean square (RMS) jitter of the phase-locked loop is reduced from 3.7 ps to 2.58 ps at 2 GHz, while the laser threshold is improved from 120 pJ to 370 pJ compared to the unhardened phase-locked loop. The hardened phase-locked loop also does not lose its lock state from linear energy transfers (LETs) of 3.3 to 37.3 MeV·cm2/mg.
Architecture Design of Protocol Controller Based on Traffic-Driven Software Defined Interconnection
LI Peijie, SHEN Jianliang, LYU Ping, DONG Chunlei, CHEN Ting
2024, 33(2): 362-370. doi: 10.23919/cje.2022.00.094
Abstract(355) HTML (179) PDF(6)
To solve the problems of redundant logic resources and poor scalability in protocol controller circuits among communication networks, we propose a traffic-driven software defined interconnection (TSDI) mechanism. The unified software defined interconnection interface standards and the normalized interconnection topology are designed to implement the architecture of TSDI-based protocol controller. The key indicators of power, performance and area (PPA) can be realized while resolving the flexible interconnection of the controller. We designed a TSDI-based RapidIO controller as an example. Compared to traditional designs, the design could achieve more protocol scalability, and RapidIO protocol standards of Gen4 could be supported directly. The key PPA indicators, such as a lower delay of 56.1 ns and more than twice throughput of 98.1 Gbps, were achieved at the cost of a 23.4% area increase.
A Design of 2-Stage Voltage Ramp-Up SRAM Physical Unclonable Function
SONG Minte, LIU Nan, ZHOU Shuaiyang, WANG Zhengguang, RU Zhanqiang, DING Peng, HUANG Wei, SONG Helun
2024, 33(2): 371-379. doi: 10.23919/cje.2022.00.406
Abstract(203) HTML (102) PDF(25)
Silicon physical unclonable function (PUF) implemented by static random access memory (SRAM) exists inherent demerit of unstable cells due to noise of environment and circuits, which significantly restricts its reproducibility. In this paper, a 16T SRAM cell with reset-delay circuit and a 2-stage voltage ramp up is fabricated and reported. Compared to conventional SRAM structure, each PUF cell adds a pair of pull-up PMOS (P-channel metal oxide semiconductor) and pull-down NMOS (N-channel metal oxide semiconductor) controlled by reset and delayed-reset signals respectively, resulting in two positive feedback stages with different amplification coefficients when the voltage is ramped up. PUF array consists of 4064 cells, 322 dummy cells and a group of 8 series-connected inverters with an area of 304 μm × 650 μm to match the digital post-processing module. PUF test chip was fabricated in HHGrace 110 nm platform with total area 1140 × 1140 μm2. The average HDintra (intra-chip Hamming distance, also bit error rate, BER) and HDinter (inter-chip Hamming distance) values of the 50 PUF chips in SOP16 package measured at normal point (1.5 V/25 ℃) were 1.92% and 49.85%, respectively.
Realization of Low in-Band Harmonic for Compact 6–18-GHz T/R Module Under TX-Mode Operation
LAI Jinming, LI Zhiyou, WANG Chaojie, WANG Hailong, MA Xiaohua
2024, 33(2): 380-384. doi: 10.23919/cje.2022.00.295
Abstract(118) HTML (58) PDF(21)
Wideband high power amplifier (PA) with poor harmonic suppression will degrade the performance of the active electronically scanned array (AESA) due to its harmonic products falling into the operating bandwidth of a wideband T/R module. In view of this, a compact reconfigurable harmonic suppress circuit (HSC) is proposed to achieve low in-band harmonic for compact T/R module with multiple octaves under TX-mode operation. The HSC consists of eight microstrip resonant stubs with high impedance and multiple p-i-n switches. By controlling the p-i-n switches, the HSC can work in three states. When six of the used p-i-n switches are “ON” state, the corresponding microstrip resonant stubs are loaded onto the 50 Ω transmission line, which performs a bandstop filter (BSF). For verification, the HSC with bandwidth of 12–15 GHz/15–18 GHz is designed to apply to a 6–18 GHz T/R module. As a result, the second harmonic of 6–9 GHz transmitting signal can be suppressed below 32 dBc when compared to the PA’s fundamental output. While the p-i-n switches are “OFF” state, the HSC is almost the same as a 50 Ω transmission line, which will have a little effect on the 9–18 GHz transmitting signal. The measurement results approximately agree with the calculated results and simulated results, which demonstrate the validity of the proposed HSC.
Analytical Models of on-Chip Hardware Trojan Detection Based on Radiated Emission Characteristics
ZHANG Fan, ZHANG Dongrong, REN Qiang, CHEN Aixin, SU Donglin
2024, 33(2): 385-392. doi: 10.23919/cje.2022.00.310
Abstract(390) HTML (198) PDF(43)
Since many third parties involved in integrated circuit (IC) manufacturing, hardware Trojans malicious implantation have become a threat to the IC industry. Therefore, varieties of reliable hardware Trojan detection methods are needed. Since electromagnetic radiation is an inherent phenomenon of electronic devices, there are significant differences in the electromagnetic radiated characteristics for circuits with different structures and operating states. In this paper, a novel hardware Trojan detection method is proposed, which considers the electromagnetic radiation differences caused by hardware Trojan implantation. Experiments of detecting hardware Trojan in field programmable gate arrays show that the proposed method can effectively distinguish the ICs with Trojan from the ones without Trojan by the radiated emission.
A Multi-Channel CMOS Analog Front-End Interface IC with 157.8 dB Current Detection Dynamic Range
WANG Kunyu, XU Wenjing, ZHANG Chengbin, YANG Yanjun, LAW Man-Kay, ZHOU Li, CHEN Jie, CHEN Ming
2024, 33(2): 393-402. doi: 10.23919/cje.2022.00.137
Abstract(173) HTML (85) PDF(27)
A high dynamic range and low-noise CMOS (complementary metal-oxide-semiconductor transistor) front-end interface integrated circuit (IC) with multi-channel detection is presented in this paper. Two different current detection channels, composed of a trans-impedance amplifier (TIA) and an integrator-differentiator TIA, are used to boost the current detection range. A capacitance-coupled instrument amplifier (CCIA) is also included to realize high precision voltage detection. A fourth-order sigma-delta modulator using a second-order loop filter and a second-order noise shaping integral quantizer is adopted to realize effective number of bits above 16 bits. The presented interface IC is implemented in 0.18-μm CMOS process with supply voltage of 3.3 V, and a proto-type electrochemical sensor platform with miniaturized sensor array is developed to verify the functionality of the interface IC. Measurement results indicate that the designed interface IC achieves 157.8 dB current detection dynamic range, and the measured input-referred current noise and voltage noise floor are 1.04 pA and 58.4 nV within 10 kHz integration bandwidths, respectively.
Design of Low-Power Turbo Encoder and Decoder for NB-IoT
ZHANG Chong, LIN Yuhang, WANG Deming, HU Jianguo
2024, 33(2): 403-414. doi: 10.23919/cje.2022.00.225
Abstract(285) HTML (142) PDF(31)
Turbo code is an error correction coding scheme close to the Shannon limit, usually used in wireless data transmission. Based on the parallel Turbo code algorithm, a parallel Turbo code circuit design scheme is proposed. In the encoder, the recursive systematic convolutional encoder is multiplexed. The decoder is divided into branch metric, recursive, maximum likelihood ratio, and external information calculation modules. The decoding algorithm is based on Max-Log-MAP, controlling the component decoder in parallel. And the state metric calculation in the decoding circuit is combined to reduce the overall power consumption effectively, enabling the encoder and decoder to be used in narrowband Internet of things (NB-IoT). Finally, the hardware scheme of the main functional modules of Turbo code encoding and decoding is designed and implemented. The results show that the dynamic power consumption is less than 50 mW. The overall on-chip power consumption is reduced by 40% at the frequency of 125 MHz compared with previous jobs.
Global Ramp Uniformity Correction Method for Super-Large Array CMOS Image Sensors
XU Ruiming, GUO Zhongjie, LIU Suiyang, YU Ningmei
2024, 33(2): 415-422. doi: 10.23919/cje.2022.00.397
Abstract(185) HTML (94) PDF(18)
Aiming at the problem of the non-uniformity of the ramp signal in the super-large array CMOS (complementary metal-oxide semiconductor) image sensors, a ramp uniformity correction method for CMOS image sensors is proposed in this paper. Based on the error storage technique, the ramp non-uniformity error is stored. And the input ramp signal of each column is shifted by level-shifting technique to eliminate the ramp non-uniformity error. Based on the 55 nm-1P4M CMOS process, this paper has completed the detailed circuit design and comprehensive simulation verification of the proposed method. Under the design conditions that the voltage range of the ramp signal is 1.4 V, the slope of the ramp signal is 71.908 V/ms, the number of pixels is 8192 (H) × 8192 (V), and a single pixel size is 10 μm, the correction method proposed in this paper reduces the ramp non-uniformity error from 7.89 mV to 36 μV. The differential non-linearity of the ramp signal is +0.0013/−0.004 LSB and the integral non-linearity is +0.045/−0.021 LSB. The ramp uniformity correction method proposed in this paper reduces the ramp non-uniformity error by 99.54% on the basis of ensuring the high linearity of the ramp signal, without significantly increasing the chip area and without introducing additional power consumption. The column fixed-pattern noise is reduced from 1.9% to 0.01%. It provides theoretical support for the design of high-precision CMOS image sensors.
An Effective Power Optimization Approach Based on Whale Optimization Algorithm with Two-Populations and Mutation Strategies
HE Juncai, HE Zhenxue, LIU Jia, ZHANG Yan, ZHANG Fan, LIANG Fangfang, WANG Tao, XIAO Limin, WANG Xiang
2024, 33(2): 423-435. doi: 10.23919/cje.2022.00.358
Abstract(206) HTML (104) PDF(23)
Power is an issue that must be considered in the design of logic circuits. Power optimization is a combinatorial optimization problem, since it is necessary to search for a logical expression that consumes the least amount of power from a large number of Reed-Muller (RM) logical expressions. The existing approach for optimizing the power of multi-output mixed polarity RM (MPRM) logic circuits suffer from poor optimization results. To solve this problem, a whale optimization algorithm with two-populations strategy and mutation strategy (TMWOA) is proposed in this paper. The two-populations strategy speeds up the convergence of the algorithm by exchanging information about the two-populations. The mutation strategy enhances the ability of the algorithm to jump out of the local optimal solutions by using the information of the current optimal solution. Based on the TMWOA, we propose a multi-output MPRM logic circuits power optimization approach (TMMPOA). Experiments based on the benchmark circuits of the Microelectronics Center of North Carolina (MCNC) validate the effectiveness and superiority of the proposed TMMPOA.
Wide Stopband Substrate Integrated Waveguide Filter Using Bisection and Trisection Coupling in Multilayer
CHU Peng, FENG Jianguo, ZHU Peng, GUO Lei, ZHANG Long, LIU Leilei, LUO Guoqing, WU Ke
2024, 33(2): 436-442. doi: 10.23919/cje.2023.00.027
Abstract(140) HTML (71) PDF(20)
This article presents a highly efficient method for substrate-integrated-waveguide (SIW) filters to achieve very wide stopbands. By employing the proposed trisection slots in addition to the bisection slots as the inter-coupling structures, all spurious modes below TE505 of a SIW filter working in the fundamental mode TE101 (f0) can be eliminated without requiring additional structure or complex theoretical analysis, without affecting the design of the fundamental passbands, and without degrading the performance of the filters. For verification, two prototype filters are designed, fabricated, and measured with wide stopbands up to 4.15f0 and 4.83f0, respectively. The proposed technique could facilitate the development of high-performance wide-stopband SIW filters for microwave/wireless circuits and systems.
The Choice of Mesh Size and Integration Points Number for the Electrostatically Controlled Membrane Antenna Structural-Electromagnetic Coupling Model
GU Yongzhen, ZHANG Qinggang, YU Xiao, LI Guixu
2024, 33(2): 443-448. doi: 10.23919/cje.2022.00.424
Abstract(139) HTML (71) PDF(16)
It is of great significance for the improvement of the computational efficiency of the electrostatically controlled membrane antenna (ECMA) structural-electromagnetic coupling model through the choice of appropriate mesh size and integration points number. In this paper, the physical optics formulation is used to analyze the radiation pattern of the ECMA surface, and the finite element method is applied to the electrostatic-structural coupling analysis. An expression for the relation between the mesh size, the focal length of the parabolic antenna, and the wavelength is developed based on the discretization error analysis of the triangular mesh approximating the parabolic surface. Moreover, the integration points number in each triangular mesh is determined by the numerical evaluation of the physical optics integral. Numerical results show that the proposed method improves the computing efficiency by about 87% compared with the referenced method.
A Tightly Coupled Dipole Array with Diverse Element Reflection Phases for RCS Reduction
GOU Yuewen, CHEN Yikai, YANG Shiwen
2024, 33(2): 449-455. doi: 10.23919/cje.2022.00.121
Abstract(307) HTML (152) PDF(40)
This paper proposes a novel low scattering tightly coupled dipole array (TCDA), aiming to reduce the radar cross section (RCS) of phased antenna arrays under a certain oblique incident wave. First, we build three types of antenna elements that exhibit similar radiation characteristics but diverse reflection phase differences based on the proposed theoretical analysis. The required reflection phase difference is achieved by using different dielectric superstrates for each antenna element. Then, by arranging the three types of subarrays next to each other, a low scattering TCDA (8 × 9) is designed. Meanwhile, a reference antenna array with a single type of antenna element is also constructed. To demonstrate the effectiveness of the proposed RCS reduction technique, simulated and measured results of the reference and proposed antenna array are compared. Both antenna arrays operate over the 6–18 GHz frequency band and can scan up to ±45° in the E-/H-planes. However, the proposed antenna array achieves a significant monostatic RCS reduction over 8–12 GHz, with a maximum reduction value of 7.55 dB. It indicates that this diverse element reflection phase technique is a good candidate for wideband RCS reduction.
Miniaturized, Wide Stopband Filter Based on Shielded Capacitively Loaded SIW Resonators
ZHENG Yan, TIAN Hanyu, DONG Yuandan
2024, 33(2): 456-462. doi: 10.23919/cje.2023.00.057
Abstract(253) HTML (125) PDF(62)
Based on the full-mode capacitively loaded substrate integrated waveguide (SIW) resonator and the miniaturized shielded half-mode capacitively loaded SIW (S-HMCSIW) cavities, a novel compact high-performance filter is proposed. The footprint of the half-mode SIW (HMSIW) is further reduced due to the application of the capacitive-loading technique. By applying cross coupling, the proposed SIW filter’s transmission zero enhances the stopband rejection and shows excellent selectivity. For the bandpass filter, the measured |S21| and |S11| are better than 1.09 dB and −14 dB, respectively. And a 3-dB fractional bandwidth (FBW) of 9.14–10.76 GHz (FBW=16.2%) is also observed. The filter achieves a wide stopband with a −20 dB out-of-band rejection up to 2.69f0 (f0 = 10 GHz), with a size of 0.39λg × 0.51λg only. Good agreement between measurement and simulation is obtained.
A Wideband High-Gain Sawtooth Slot Array Antenna with Frequency-Scanning at Lower Frequency and Fixed-Beam at Higher Frequency
SUN Qiang, BAN Yongling, HU Jun
2024, 33(2): 463-471. doi: 10.23919/cje.2022.00.332
Abstract(118) HTML (61) PDF(16)
Exploring the multifunctional array antenna suitable for complex communication environment has very important research value. In this paper, a millimeter wave (mm-wave) double longitudinal sawtooth slot array antenna (DLSA) based on substrate integrated waveguide (SIW) technology is proposed, which has wideband, high-gain and novel beam characteristics. Two irregular longitudinal slots are etched on the SIW conductor surface as the radiation structure. To improve the bandwidth of the DLSA, the metallized vias are added at the transition point of the slots to construct multiple resonant frequency points. By adjusting the size of the slots and the position of the metallized vias, the phase constant can be regulated, and the unusual beam characteristics can be obtained. That is to say, in the lower frequency band, the beam pointing angle increases with frequency. In the higher frequency band, the beam pointing angle is maintained at a fixed angle. Finally, to improve the antenna gain, a 16 × 8 DLSA is fabricated, measured and discussed. The proposed antenna has an impedance matching bandwidth close to 9.7 GHz. From 27 to 33 GHz, the beam pointing angle changes from 8° to 29°. From 33 to 37 GHz, the beam pointing angle is fixed at 29°, and the pointing angle error range is ±1°. In addition, the measured maximum gain is 22.9 dBi at 32 GHz.
A Novel Approach of Electromagnetic Compatibility Conducted Susceptibility Analysis Based on Gaussian Even Pulse Signal
MENG Youwei, PENG Yanhua, ZHANG Haoyang, LI Lilin, SU Donglin
2024, 33(2): 472-478. doi: 10.23919/cje.2022.00.298
Abstract(359) HTML (177) PDF(43)
The purpose of the electromagnetic compatibility conducted susceptibility test for interconnected cables in the system is to evaluate its ability to operate acceptably when subjected to interference. We propose a novel conducted susceptibility analysis approach: by injecting the Gaussian even pulse signal, we find that the susceptibility threshold of the system shows two different patterns with the change of signal parameters; then we locate the cause of the susceptibility of the device by analyzing the threshold level curves. The effectiveness of the proposed approach is verified by testing with devices containing digital modules such as navigation receivers. The proposed approach facilitates a deeper understanding of the susceptibility mechanism of systems and their appropriate electromagnetic compatibility design.
The Establishment and Analysis of the Structural-Electromagnetic Coupling Model of the Electrostatically Controlled Deployable Membrane Antenna
ZHANG Shunji, GU Yongzhen, ZHONG Wang, ZHANG Qinggang
2024, 33(2): 479-487. doi: 10.23919/cje.2022.00.328
Abstract(149) HTML (76) PDF(17)
A new structural-electromagnetic coupling (SEC) analysis based on quadratic elements is proposed to solve the mismatch problem between structural elements and electromagnetic grids of the electrostatically controlled deployable membrane antenna (ECDMA). Firstly, the ECDMA reflector surface is meshed and redefined by a series of quadratic elements. Without grid transformation, the calculating formulas for the far-field pattern of ECDMA are derived by the physical-optics method. Then the structural deformation of ECDMA is analyzed and the far-field pattern calculating formulas including deformation errors are developed. Simulation and experiment results show that the quadratic elements are effective and efficient in SEC analysis of the ECDMA, moreover, the electromagnetic grid size demand and the grid discretization error are reduced greatly.
Mode Competition of Low Voltage Backward Wave Oscillator near 500 GHz with Parallel Multi-Beam
ZHAO Xiaoyan, HU Jincheng, ZHANG Haoran, GUO Sidou, FENG Yuming, TANG Lin, ZHANG Kaichun, LIU Diwei
2024, 33(2): 488-495. doi: 10.23919/cje.2022.00.003
Abstract(335) HTML (170) PDF(31)
A backward wave oscillator with parallel multiple beams and multi-pin slow-wave structure (SWS) operating at the frequency above 500 GHz is studied. Both the cold-cavity dispersion characteristics and CST Particle Studio simulation results reveal that there are obvious mode competition problems in this kind of terahertz source. Considering that the structure of the multi-pin SWS is similar to that of two-dimensional photonic crystals, we introduce the defects of photonic crystal with the property of filtering into the SWS to suppress high-order modes. Furthermore, a detailed study of the effect of suppressing higher-order modes is carried out in the process of changing location and arrangement pattern of the point defects. The stable, single-mode operation of the terahertz source is realized. The simulation results show that the ratio of the output peak power of the higher-order modes to that of the fundamental mode is less than 1.9%. Also, the source can provide the output peak power of 44.8 mW at the frequency of 502.2 GHz in the case of low beam voltage of 4.7 kV.
High-Efficiency Wideband Transmitarray Antenna Using Polarization-Rotating Elements with Parasitic Stubs
WANG Xi, DONG Yuandan
2024, 33(2): 496-503. doi: 10.23919/cje.2023.00.094
Abstract(231) HTML (114) PDF(41)
A high-efficiency polarization-rotating transmitarray antenna (TA) using wideband elements is proposed for millimeter-wave applications. The polarization-rotating element consists of three metallic layers and two substrates. Orthogonal polarizers are employed on the top and bottom of the element. And the split ring with a parasitic stub on the middle layer is symmetric about the diagonal, performing the polarization rotation and phase compensation simultaneously. A parasitic stub is designed to decrease transmission loss and broaden the bandwidth. The periodicity of the element is only 1/4 wavelength at 30 GHz. A prototype TA with 28 × 28 elements is designed, fabricated, and measured. The measured peak gain reaches 27.5 dBi at 37.8 GHz. The 1-dB gain drop bandwidth is 30.8–40 GHz (26.0%). The aperture efficiency reaches as high as 71% at 31.5 GHz. Within the bandwidth of 26.5–38.8 GHz (37.7%), the aperture efficiency is higher than 50%. The proposed polarization-rotating TA features wide bandwidth and high efficiency, demonstrating great application potential for 5G millimeter-wave communication.
Blind Signal Reception in Downlink Generalized Spatial Modulation Multiuser MIMO System Based on Minimum Output Energy
WU Wei-Chiang
2024, 33(2): 504-515. doi: 10.23919/cje.2022.00.113
Abstract(439) HTML (221) PDF(24)
This paper considers downlink multiuser multiple-input-multiple-output system with parallel spatial modulation scheme, in which base station transmitter antennas are separated into K groups corresponding to K user terminals. Generalized spatial modulation is employed, in which a subset (more than single antenna) of transmit antenna array are activated and the activating pattern corresponds to specific spatial symbol. Different from existing precoding-based algorithms, we develop a two-stage detection scheme at each user terminal: In the pre-processing stage, a minimax algorithm is proposed to identify the indices of active antennas, where the key idea is that the minimum output energy of the detector is maximized; A constrained minimum output energy algorithm is proposed in the post-processing stage to mitigate multiuser interference and extract temporal symbols. Compared with existing precoding-based algorithms, the complexity is significantly reduced. Moreover, the proposed algorithm is semi-blind, in which only a small subset of channel state information is required to identify active antennas as well as eliminate multiuser interference. Simulation results demonstrate that the proposed algorithm is near-far resistant and the spectral efficiency is extensively increased compared to the conventional spatial modulation scheme.
A Compact Filtering Antenna System with Wide-Angle Scanning Capability for V2I Communication
HAN Chuang, LI Tong, ZHANG Zhaolin, WANG Ling, YANG Guangwei
2024, 33(2): 516-526. doi: 10.23919/cje.2023.00.039
Abstract(212) HTML (107) PDF(21)
A compact filtering antenna system with wide-angle scanning is proposed for vehicle to infrastructure (V2I) communication which would handle complex communication scenarios. In this work, a wide beam filtering antenna is realized by using some inductive resistance structures such as metal pins and pillars, and capacitive structures such as slots, parasitical patches to produce the radiation nulls at two sides of the operating frequency band and improve the impedance matching in the passband. Meanwhile, the wide beam capability is also realized by the above structure. Furthermore, two H- and E-plane linear arrays are designed for the beam scanning capability with filtering characteristics based on the proposed antenna. To verify the proposed design concept, a prototype is fabricated and measured. The measurement and simulation agree well, demonstrating an excellent filtering characteristic with the operating frequency band from 3.18 to 3.45 GHz (about 8.1%), the high total efficiency of about 88%, and 3-dB-beamwidth of more than 100° and 120° in the above two arrays, respectively. Additionally, the proposed arrays can realize the beam scanning up to the coverage of 112° and 120° with a lower gain reduction and a good filtering characteristic, respectively.
Optical Space Time Pulse Position Modulation over Exponential Weibull Turbulence Channel
ZHANG Yue, WANG Huiqin, MA Xuemei, CAO Minghua, PENG Qingbin
2024, 33(2): 527-535. doi: 10.23919/cje.2022.00.097
Abstract(160) HTML (80) PDF(15)
An optical space time pulse position modulation (OSTPPM) scheme is proposed to satisfy the communication requirement of high transmission rate and better reliability. For the OSTPPM scheme, an improved threshold judgment-based orthogonal matching pursuit (IT-OMP) algorithm with low-complexity and near optimal performance is proposed. The average bit error rate of OSTPPM-IT-OMP scheme is investigated over the exponential Weibull channel, and its analytical expression is verified via Monte Carlo simulation. With the same simulation parameters, the signal to noise ratio of (4,4,2)-OSTPPM-IT-OMP is respectively 3.75 dB and 8.5 dB better than that of spatial pulse position modulation (SPPM) scheme and generalized spatial pulse position modulation (GSPPM) scheme at a bit error rate of 1 × 10−3. With the same transmission bits per symbol, the computational complexity of (3,4,2)-OSTPPM-IT-OMP scheme is reduced by 90.47% and 75.4% compared with (16,4,2)-SPPM and (5,4,2)-GSPPM schemes, respectively.
Joint Transmit and Reflective Beamforming Design for Active IRS-Aided SWIPT Systems
SHI Weiping, WU Qingqing, WU Di, SHU Feng, WANG Jiangzhou
2024, 33(2): 536-548. doi: 10.23919/cje.2022.00.287
Abstract(664) HTML (329) PDF(112)
To further improve the performance of passive intelligent reflecting surface (IRS)-assisted communication systems and mitigate the serious path loss due to “double-fading” of IRS-assisted links, an active IRS-aided simultaneous wireless information and power transfer (SWIPT) system is investigated. This paper jointly optimizes the transmit beamforming at the base station (BS) and the phase shifts at the active IRS in order to maximize the power collected by the energy harvesting receiver under both perfect and imperfect channel state information (CSI) states, subject to the signal-to-interference-noise ratio constraint of the information decoding receiver, and the power constraints of the BS/IRS. Under perfect CSI, the alternating optimization algorithm is utilized for obtaining the transmit beamforming at the BS and the phase shifts at the active IRS. For each subproblem, we first transform non-convex objective function and constraints into convex ones by performing a first-order Taylor expansion. Then, each subproblem is solved by using the interior point method. Given that obtaining perfect CSI is impractical, two robust beamforming designs are proposed for imperfect CSI case. Under the bounded CSI error model, we first transform the non-convex optimization problem into two semidefinite programming subproblems, and then solve each subproblem based on S-procedure and sequential rank-one constraint relaxation (SROCR) techniques. Under the stochastic CSI error model, the alternating optimization method is applied in an iterative manner based on Bernstein-type inequality and SROCR technique. Simulation results show that both robust and non-robust schemes for active IRS-assisted SWIPT systems can achieve extremely superior performance over conventional passive IRS-assisted systems under the same overall power budget.
Formal Modeling of Frame Selection in Asynchronous TSN Communications
LI Ershuai, ZHOU Xuan, SUN Jinjing, XIONG Huagang, HE Feng
2024, 33(2): 549-563. doi: 10.23919/cje.2022.00.321
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The asynchronous time-sensitive networking (TSN) based on IEEE 802.1Qcr is expected to be a promising solution for the asynchronous transmissions of safety-critical flows without the support of clock synchronization. When the asynchronous traffic shaping (ATS) mechanism is adopted to meet the deadline requirements for transmissions of safety-critical flow, it is necessary to formally verify the real-time properties and corresponding network performance. However, it is still unclear how to build an efficient formal model to evaluate different frame selection methods during the ATS scheduling process, which originate from the dominations of priority or eligibility time. In this paper, we present a formal modeling framework to compare the impacts of different frame selection on transmission sequence under the ATS mechanism. According to the priority level (pATS) or eligibility time (eATS) for flows, two transmission selection methods in ATS are modeled and compared. Then, we verify the real-time properties of ATS. The result shows that the shaping-for-free property can be satisfied with the pATS method but can not be fulfilled with the eATS method. Besides, the timing analysis results illustrate that the eATS method can provide more fairness than the pATS method for the transmission of low-priority flows in TSN networks.
Performance Study of MIMO-OSTBC Parallel Relay FSO System Based on GFDM
2024, 33(2): 564-572. doi: 10.23919/cje.2022.00.069
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This paper investigates the performance of a new generalized frequency division multiplexing (GFDM) parallel relay free space optical (FSO) communication system using multi-input multi-output (MIMO) orthogonal space-time block codes (OSTBC) scheme. Under the M distribution atmospheric turbulence, taking into account the triple effects of irradiance, pointing errors and path loss, the mathematical expression of system symbol error rate is derived with the help of Meijer G-function. The symbol error performance of GFDM is compared with on-off keying, Gaussian minimum shift keying, polarization shift keying and orthogonal frequency division multiplexing (OFDM) modulation methods. The effects of the MIMO-OSTBC parallel relay scheme on the GFDM system including filter roll down coefficient, the number of transmitting and receiving antennas, the number of relays, normalized beamwidth and jitter variance are analyzed, and the numerical results are verified by Monte Carlo simulation. This work provides a good foundation for engineering applications.