一、引言我们设计的12.4～18千兆赫波导型吸收式PIN电调衰减器,是由六个PIN管相隔四分之一波长并联地安装在脊波导内构成的,PIN二极管装置的截面图及其等效电路如图1所示。图中,L_p为线柱电感;C为电路电容;C_p为线柱电容;C_d为管芯电容;R_d为PIN管的结电阻(它随偏流而改变),X_h为扼流系统的输入阻抗;Z_0为脊波导的特性阻抗;Z_0＇为h段同轴线的特性阻抗。只有测量出具体微波电路的各个等效电路参量的数值,才能运用级联[A]矩阵的 I. INTRODUCTION The 12.4 ~ 18 Gigahertz absorption PIN electric attenuator designed by us is a cross-sectional view of a PIN diode device with six PIN tubes installed in parallel in the ridge waveguide at a quarter wave length. The equivalent circuit shown in Figure 1. C_d is the column capacitance; C_d is the die capacitor; R_d is the junction resistance of the PIN tube (which changes with the bias current); X_h is the input impedance of the choke system; Z_0 is the characteristic impedance of the ridge waveguide; Z_0 ’is the characteristic impedance of the h-axis coaxial line. Only by measuring the value of the equivalent circuit parameters of a specific microwave circuit can we use the cascaded [A] matrix