A wideband dual-line polarized antenna with low-profile property is presented in this paper. The dual-polarized antenna consists of two crossed antenna elements over a metal reflector and is excited by RF connectors vertically. Here, the crossed antenna element is based on Vivaldi radiator to obtain wideband performance. By loading resistors on the patches of Vivaldi radiator, not only the impedance matching of the proposed antenna can be improved further but also the profile is reduced greatly. Whatever, the loaded resistors can also depress radiation efficiency of the antenna element to a certain extent, especially in the lower band. For this reason, three periodic slots etched on the Vivaldi radiator are introduced herein to enhance the gain performance. To verify the feasibility of the proposed design, a prototype has been fabricated and measured. The results show good performance of a relative bandwidth of 153% for VSWR ≤ 2 (2-15GHz) and a low profile of 0.22λ_L (in terms of the lowest frequency of the band). Besides, the prototype can achieve an average gain of approximately 5dBi and a maximum radiation efficiency of 80% within passband.

The novel rare earth variable flux permanent magnet synchronous motor (PMSM) for electric vehicles is proposed. The structure and magnetic field regulation characteristics are analyzed, the variation of magnetic density, no-load back electromagnetic force and output torque with speed was studied through finite element simulation. The weak magnetic field expansion speed performance of the novel PMSM has been verified through experimental equipment. The adjustable electromagnetic field with running speed on the rare earth PMSM increases the high-speed operation range of vehicle.

In order to solve the problems of the traditional model reference adaptive system (MRAS) speed estimation adaptive mechanism, such as poor tracking accuracy and slow response, A new dual sliding mode adaptive observer is designed to estimate the rotational speed and rotor position of permanent magnet synchronous motor (PMSM). Firstly, a new two-variable complex reaching law is used to replace the traditional first-order sliding mode for velocity loop control, and an anti-saturation scheme is introduced to improve the anti-interference ability of the system. Secondly, the PI adaptive mechanism in the traditional MRAS is replaced by a new super-twisting weighted integral type algorithm adaptive observer (STWITA-AO), which effectively speeds up the convergence of the estimated speed and reduces the inherent chattering of the sliding mode structure. Finally, the relevant simulation is compared and verified. The simulation results show that the estimation strategy based on the new double sliding mode MRAS control can make the speed estimate converge to the actual value faster, and improve the dynamic performance and robustness of the observer.

A wideband crossed dipole antenna for dual-polarized applications is presented in this paper. The antenna consists of a printed crossed dipole radiator loaded with periodic slots, four metal posts, four metal sidewalls and a metal reflector. The crossed dipole antenna is directly fed by a simple coaxial cable, achieving stable dual-polarization radiation characteristics. Here, two approaches are adopted to adjust the high and low resonant frequency of the antenna with large freedom. Firstly, four metal posts are introduced into conventional crossed dipole antenna, and their distance from the feeding point can independently adjust the lower resonant mode. Secondly, periodic slots are etched on the crossed dipole arms, and the upper resonant frequency can be controlled independently by altering the length of these slots. Also, the metal sidewalls on the ground are used herein to obtain enhanced gain property. To verify the feasibility of the proposed design, a prototype has been fabricated and measured. The measured results show good performance of a relative bandwidth of 64.3% for VSWR ≤ 2 (1.32-2.57GHz). Moreover, the antenna has good unidirectional radiation performance and can achieve maximum gain of 9.1dBi at 2.3GHz.

This paper presents a 2:1 analog multiplexer (AMUX) using IHP’s 130-nm SiGe BiCMOS process. The proposed AMUX expands the analog bandwidth (BW) of CMOS-based DACs by introducing interleaving sampling technique, thus improving the data rate of single lane in modern optical communication systems. Meanwhile, a detailed analysis of process selection which particularly focuses on material and device considerations is adopted, and a principle of the BW expansion is comprehensively discussed. The AMUX exhibits a BW >70GHz, achieving a data rate of 200Gb/s under PAM-4 modulation.

In this paper, a multi-objective optimization strategy is proposed for the design of high-density low-noise motors. The approach considers efficiency and computational accuracy and uses a wide-frequency-domain multi-operating-condition electromagnetic vibration source as the objective function. The first step is to identify the wide-speed multi-operating-condition vibration source of the motor using the unit-force-wave response method. Then, a multi-objective optimization model of high-density low-noise motors is established by combining electromagnetic design objectives to create a mapping relationship between the electromagnetic noise source and the structural parameters. This method optimizes a 48-slot 8-pole IPMSM for suppression in electric vehicles. The amplitude of the vibration source of the prototype is reduced by 80.73% and 85.48%, respectively, while the average torque remains unchanged. The vibration acceleration of the motor is significantly suppressed under the wide frequency domain multi-operating conditions. This paper provides technical support and design references for engineering applications.

This brief presents a fully integrated automatic impedance-matching RF energy harvesting system that automatically compensates for variations at the antenna-rectifier interface. The control loop is fully integrated on-chip with a low-voltage, low-power design. The design is fabricated in 0.18-µm CMOS technology, and the active chip area is 0.064mm². The sensitivity optimized by impedance tuning can be improved to more than -30.5dBm for 0.7V output at varied initial mismatches, leading to a maximum increase in sensitivity of 5dB. The control circuit’s power consumption is only 2.4nW, and the minimum supply voltage is 416mV.

An accurate and efficient electromagnetic (EM) modeling approach based on Neuro-space mapping (Neuro-SM) is proposed for substrate integrated suspension line (SISL) devices. A new coarse model containing 1 layer of dielectric plates, 2 layers of metal plates and 2 air cavities are developed to accelerate EM model simulation speed. To improve EM model accuracy, a parameter mapping network and a frequency mapping network are added into the structure. The EM responses of the SISL devices are taken as the fine model, while the proposed coarse model and two mapping networks are considered as the advanced Neuro-SM model. A three-step training process is developed to reduce errors between the fine and Neuro-SM model. The reasonable Neuro-SM model structure and efficient training algorithm greatly simplify the SISL device modeling process and further shorten the SISL device design cycle. The experimental results of a low-pass filter with SISL structure show that the training and test errors of the proposed model are 1.1% and 1.3%, which proves that the established model could accurately represent the characteristic of the SISL device.

In this paper, a family of zero voltage switching (ZVS) buck/boost converters with positive common rail (PCRBBC) is proposed for the PMSM sensorless driving system in electric vehicles. The proposed family of PCRBBCs includes more than 12 topologies with coupled LC or LD auxiliary circuits. Their special characteristics are the common positive connection between input and output ports, ZVS conditions, and a variety of different topologies to be chosen. The operation principle, soft-switching realization limit, application conditions, design guidance of proposed ZVS PCRBBCs are analyzed. Finally, an experimental prototype is built to verify the correctness and validity of the proposed soft-switching topologies.

Weak resistive defects in standard cells exhibit subtle electrical behaviour that may lead to test escapes, thereby compromising the reliability of integrated circuits. Fault analysis data has shown that the presence of weak defects in specific cells can cause variations in output timing when multiple transitions occur on the inputs, as opposed to a single transition. However, existing delay test generation tools do not account for the effect of multiple input switching (MIS). In this paper, the effects of MIS on defect detection and timing analysis are analyzed and a multi-transition delay test method is proposed to further expose and detect cell internal defects. In addition to sensitizing the selected paths, the new test pattern attempts to maximize the off-path input transitions, thus increasing the propagation delay of the selected paths or the proportion of incremental delay introduced by the defects. The simulation results on ISCAS benchmark circuits show that the proposed method achieves a maximum of 8.73% and an average of 5.99% defect coverage gain compared to the existing delay tests that based on single input switching schemes.