The classical formula of a parallel plate capacitor (PP-Cap) does not take fringing effects into consideration, which assumes that the side length of a PP-Cap is by far larger than the distance between the two plates. However, for capacitive power transfer applications, especially those designed for electric vehicle charging, this assumption no longer holds since the distance can be as large as 150 mm. Based on conformal mapping, the corrected or improved formula of PP-Cap with the consideration of fringing effect can be obtained; nevertheless, some approximations are introduced for the convenience of calculation. By finite element method (FEM) simulation and experimental measurement, this paper investigates the influencing factors of large distance PP-Cap especially in the capacitive power transfer application and thereby the proposed formula with improved accuracy is verified.

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We focus on a new kind of vector optical field with bipolar symmetry of linear polarization instead of cylindrical and elliptical symmetries, enriching members of family of vector optical fields. We design theoretically and generate experimentally the demanded vector optical fields and then explore some novel tightly focusing properties. The geometric configurations of states of polarization provide additional degrees of freedom assisting in engineering the field distribution at the focus to the specific applications such as lithography, optical trapping, and material processing.

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The grounded electrical-source airborne transient electromagnetic signal is significantly affected by electromagnetic noise (sferics and aircraft engine electromagnetic noise), leading to inferior image formation. We calculate the theoretical response of the grounded electrical-source airborne transient electromagnetic system and propose a denoising algorithm based on the transient characters of the theoretical electromagnetic response and the measured noise. The proposed algorithm utilises multi-resolution analysis via a stationary wavelet transform of the data. Primarily, the measured data are decomposed into detailed coefficients and approximated coefficients. Then, the logarithmic slope of the measured data and a threshold are calculated to identify the noise in the detailed coefficients; the corresponding detailed coefficients are processed to reduce the noise. Finally, the undisturbed data are reconstructed using inverse stationary wavelet transform. The algorithm is verified using synthetic signal and is applied for electromagnetic noise suppression in synthetic data and real data collected over the coastal areas in Yanwei Harbor, China. The results confirm that the denoising algorithm can effectively remove the electromagnetic noise from the grounded electricalsource airborne transient electromagnetic signal. Moreover, the image formations clearly reveal the structure of the Huaiyin-Xiangshui fault zone. from the aircraft engine, leading to inferior image quality. Therefore, it is necessary to develop an effective denoising algorithm to obtain a high signal-to-noise ratio (SNR) and to improve the interpretation quality of the electromagnetic data.With the development of the signal processing technology, studies on airborne and grounded-airborne electromagnetic data denoising have made progress. Lemire (2001) designed an algorithm based on the Lagrangian optimisation method to correct the baseline drift. Bouchedda et al. (2010) reported a filter using stationary wavelet transform (SWT) to remove the sferics noise from the airborne transient electromagnetic data. Reninger et al. (2011) adopted a singular value analysis method to remove white noise and sferics from airborne transient electromagnetic data. Chen, Lu and Liu (2014) proposed a kernel principal component analysis to address the natural and aircraft noise in airborne transient electromagnetic data. Wang et al. (2013) used a wavelet-based method to correct the baseline drift of grounded-airborne electromagnetic data. Li et al. (2013) utilised a combined wavelet transform algorithm for grounded-airborne electromagnetic data that can reduce the white noise while solving the problem of baseline drift; how-

The wire loop method of the transient electromagnetic (TEM) method is used to nondestructively detect conductor breaks of grounding grid. For this purpose, grounding grids serve as an underground wire loop, and the measuring points are arranged on the ground. At each measuring point, a receiving loop is employed to detect the electromagnetic response generated by transmitting the current of the transmitting loop. Conductor breaks can be diagnosed by analyzing the slices of the electromagnetic response. We study the effect of loop size and height difference through the simulation of an intact 2×2 grounding grid, confirming that it is easier to obtain the topological structure using a small transmitting loop and a small height difference. Furthermore, simulations of an intact 4×4 grounding grid and grids with different locations of conductor breaks are also conducted with a small transmitting loop. It is easy to distinguish the topological structure of the grounding grid and the locations of conductor breaks. Finally, the detection method is applied experimentally. The experimental results confirm that the proposed method is an effective technique for conductor break diagnosis.