The swarm parameters of the negative corona discharge are improved to calculate the discharge model under different environmental conditions. The effects of temperature, humidity, and air pressure are studied using a conventional needle-to-plane configuration in air. The electron density, electric field, electron generation rate, and photoelectron generation rate are discussed in this paper. The role of photoionization under these conditions is also studied by numerical simulation. The photoelectrons generated in weak ionization region are proved to be dominant.

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Gain curve of the conventional Vivaldi antenna (CVA) decreases at higher frequencies. A dielectric cover is proposed to correct this problem. The detailed analysis, design and discussion for the CVA with shaped dielectrics (SDCVA) have been carried out. Both the CVA and the DSCVA are fabricated and tested. The results show good agreement with the simulated ones. The measured results show that the proposed SDCVA provides a gain variation of 5.2–14.2 dBi in the wide operating range from 3.5 to 16.5 GHz, which corresponds to a gain enhancement of 0.5–6.5 dBi compared to the CVA. In addition, the E‐plane half power beamwidths are narrowed significantly at higher frequencies. An average improvement of 3.58 dB is achieved in terms of the front‐to‐back ratio. The sidelobe levels, on average, are reduced by 5.88 dB and 3.47 dB for E‐plane and H‐plane, respectively.

The effect of photoionization on the negative corona discharge was simulated based on the needle to plane air gaps. The Trichel pulse, pulse train, electron density and the distribution of electric field will be discussed in this manuscript. Effect of photoionization on the magnitude and interval of the first pulse will be discussed for different applied voltages. It is demonstrated that the peak of the first pulse current could be weakened by photoionization and a critical voltage of the first pulse interval influenced by photoionization was given.

Laminated busbars connect capacitors with switching power modules and they are designed to have low stray inductance to minimize electromagnetic interference. Attempts to accurately measure the stray inductance of these busbars have not been successful. The challenge lies with the capacitors as each of them excite the busbar producing their individual stray inductances. These individual stray inductances cannot be arithmetically averaged to establish the total stray inductance that applies when all the capacitors excite the busbar at the same time. It is also not possible to measure the stray inductance by simultaneous excitation of each capacitor port using impedance analyzers. This paper presents a solution to the above dilemma. A vector synthesis method is proposed whereby the individual stray inductance from each capacitor port is measured using an impedance analyzer. Each stray inductance is then mapped into an x-y-z frame with a distinct direction. This mapping exercise allows the data to be vectored. The total stray inductance is then the sum of all the vectors. The effectiveness of the proposed method is demonstrated on a busbar designed for H-bridge inverters by comparing the simulation and practical results. The absolute error of the total stray inductance between the simulation and the proposed method is 0.48nH. The proposed method improves the accuracy by 14.9% compared to the conventional technique in measuring stray inductances.