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A novel three-dimensional (3-D) frequency selective surface (FSS) exhibiting wide- band and highly selective bandpass response is presented. The proposed FSS consists of a two- dimensional periodic array of vertical, shielded, and suspended striplines. By combining the high- pass property of the periodic array of waveguides with bandstop resonances from the inserted U-shaped striplines, a quasi-elliptic bandpass frequency response over a wide-band from 8.4 GHz to 16.2 GHz is achieved with a 3 dB frequency bandwidth of 63% and a sharp rejection skirt.

This paper presents a polarization converter that a linearly polarized incident wave can be converted into a circularly polarized wave. The proposed structure is composed of a two-dimensional periodic arrangement of dielectric-filled substrate integrated waveguide cavities (SIWC) in unit-cell of which double-layer slot frequency selective surface (FSS) cascaded with dielectric layers. Through the coupling of the input and output waves with slots on the layers, two linearly polarized outgoing waves with orthogonal polarization can be transmitted. When the two orthogonally polarized components are combined and adjusted with equivalent amplitude and 90° phase difference, they can be synthesized into circularly polarized wave.

Improving carbon emission efficiency in China is conducive to achieving the win-win situation of economic growth, energy conservation and emissions reduction but it is also crucial to be able to accurately measure it. Based on an improved non-radial directional distance function, the paper constructs a new meta-frontier total-factor carbon emission efficiency index by considering technology heterogeneity. In order to reveal the source of efficiency losses, we look at the two dimensions of production technology and management so as to be able to then decompose the meta-frontier carbon emission inefficiency into technology gap inefficiency and managerial inefficiency. Following this, we measure the meta-frontier total-factor carbon emission efficiency of China’s 31 manufacturing industries from 2012 to 2016 and analyze the root causes of their carbon emission inefficiency. The results show that, during the investigation period, the meta-frontier total-factor carbon emission efficiency of China’s manufacturing industry was low and there was significant industrial heterogeneity. The meta-frontier total-factor carbon emission efficiency of high-tech industry was the highest, followed by that of middle-tech industry, with the lowest being low-tech industry. The root cause of carbon emission inefficiency in China’s manufacturing industry mainly lies in the low level of management. With improvements in industrial technological levels, managerial inefficiency gradually increases as a percentage of the total even though technology gap inefficiency gradually decreases. Based on the above results, we suggest measures to improve carbon emission efficiency for those various manufacturing industries characterized by different technology levels.

The response of a receiving antenna to the high power microwave irradiation is analyzed by using the finite integration technique (FIT). Typical excitation signals are applied to examine the effect of the excitation to the response. The results reveal that the waveform of the response signal is mainly decided by the excitation signal and the operating frequency band of the receiving antenna.

Current probe is a detection method commonly used in electromagnetic compatibility. With the development of power electronics technology, the power level of power conversion devices is constantly increasing, and the power current of the electric energy conversion device in the electromagnetic launch system can reach 10kA. Current probe conventionally used in EMC (electromagnetic compatibility) detection cannot meet the test requirements on high current system due to the magnetic saturation problem. The conventional high current sensor is also not suitable for the RF (Radio Frequency) interference current measurement in high current power device due to the high noise level in the output of active amplifier. In this paper, a passive flexible current probe based on Rogowski coil and matching resistance is proposed that can withstand high current and has low noise level, to solve the measurement problems of interference current in high current power converter. And both differential mode and common mode current detection can be easily carried out with the proposed probe because of the probe’s flexible structure.

In power electronic devices, the winding temperature of the transformer in operation needs to be monitored in real time. But the Electromagnetic Interference(EMI) problems cause the measured winding temperature fluctuates anomalously. In this paper, the 10MVA transformer in the cabinet of a transformer rectifier is studied as a specific case, the temperature measurement circuit of the transformer winding is introduced, according to which the causes of winding temperature fluctuation is analyzed. Finally, the solution of the winding temperature fluctuation is proposed and verified by experiments.