A Method for Calculating the Shielding Effectiveness of Radio Fuze Cavity

doi:10.12382/bgxb.2021.0888

Abstract

Abstract:

The internal space of radio fuzes is limited, making it difficult to measure the electromagnetic shielding effectiveness (SE) of their cavity through experiments. To analyze the SE of the radio fuze cavity under the circumstance of a strong electromagnetic pulse, a calculation method on electromagnetic topology theory and Baum-Liu-Tesche (BLT) equation is proposed in this paper. This method establishes the cavity propagation matrix by analyzing the energy flow characteristics, calculates the cavity scattering matrix by using the equivalent circuit model, deduces the extended BLT equation of energy transmission in the cavity, and then obtains the voltage value of each topological node. The effectiveness of this method is verified using CST software. The SE of various models, including the rectangular antenna window model, circular antenna window model, double-sided circular hole model, and dielectric substrate model, is calculated. The calculation results are analyzed quantitatively using the correlation coefficient, and the results show that the calculation accuracy of the proposed method is better than that of the equivalent circuit method. The needed calculation memory is lower than that of the CST software. This method can be used to analyze the SE of fuzes with cylindrical cavities.

Key words: radio fuze, electromagnetic topology, electromagnetic shielding effectiveness

CHEN Kaibai, GAO Min, ZHOU Xiaodong, BI Junjian, WANG Yi. A Method for Calculating the Shielding Effectiveness of Radio Fuze Cavity[J]. Acta Armamentarii, 2023, 44(4): 1200-1208.

Figures/Tables 18

Fig.1 Simplified fuze cavity model

Fig.2 Equivalent fuze cavity circuit

Fig.3 Electromagnetic topology model of fuze cavity

Table 1 Model parameters of the cavitymm

模型参数	数值
r	80
d	150
t	1
l	20
w	20
p	80

Fig.4 Calculation results of the rectangular antenna window

Fig.5 Comparison between the resampling curve and original curve

Table 2 Correlation coefficient of the SE curve of the rectangular antenna window

计算方法	ρ_X_,_Y
本文方法	0.9425
等效电路法	0.8643

Table 3 Model parameters of the cavitymm

模型参数	数值
r	80
d	150
t	1
r_a	10
p	80

Fig.6 Calculation results of the circular antenna window

Table 4 Correlation coefficient of the SE curve of the circular antenna window

计算方法	ρ_X_,_Y
本文方法	0.9573
等效电路法	0.8773

Fig.7 Equivalent circuit model of the double-sided perforated cavity

Fig.8 Energy flow model of the double-sided perforated cavity

Fig.9 Calculation results of the double-sided circular hole

Table 5 Correlation coefficient of the SE curve of the double-sided circular hole

计算方法	ρ_X_,_Y
本文方法	0.9445
等效电路法	0.8749

Fig.10 Circuit model of the cavity containing dielectric substrate

Fig.11 Energy flow model of the cavity containing dielectric substrate

Fig.12 Calculation results of the cavity containing dielectric substrate

Table 6 Correlation coefficient of the SE curve of the model containing dielectric substrate

计算方法	p₁/mm
计算方法	5	10
本文方法	0.9715	0.9163
等效电路法	0.9271	0.9102

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