Study Of Field-to-Wire Coupling Based On Antenna Reciprocity Theorem

Electromagnetic compatibility(EMC)is one of the key problems to ensure the reliability of electronic products,In the design phase,It is of great significance to evaluate and predict the effects of different radiation interference.This paper has done a series of research on the field to line coupling based on antenna reciprocity theorem,The main research contents are as follows:(1)Transmission line is equivalent to multi-port antenna system,the response of the linear termination to the linear polarized radiation field is derived according to the parameters of the system obtained in transmit mode based on antenna reciprocity theorem.Moreover,the BLT equation of microstrip line is derived,and comparison of the reciprocity theorem,the BLT equation and the direct full wave simulation results is carried out,validating the effectiveness of the method based on reciprocity theorem to solve the response of microstrip line in free space.(2)The method of reciprocity theorem is applied to calculate the response of microstrip enclosed in apertured cavity,termination response to the circular polarized radiation field is derived and verified for the first time.Combining with the Monte-Carlo method,the probability distribution of the maximum received power and the bit error rate of digital system under complex electromagnetic environment are evaluated thank to the high efficiency of reciprocity theorem.(3)Combining the electromagnetic simulation software with the circuit simulation software according to Thevenin equivalent circuit,The time domain waveform of sampling function and period pulse are analyzed,time domain and frequency domain responses of linear and nonlinear loads on single conductor and microstrip transmission lines are calculated.This method is applicable for the analysis of arbitrary waveform interference by Fourier transformation.(4)A microwave power amplifier circuit enclosed in apertured cavity is studied,a novel hybrid method of full wave simulation and circuit simulation is proposed to take the influence of impedance change of nonlinear device into account,the worst-case of the influence of the single frequency radiation interference on the gain of the power amplifier circuit is analyzed.