150 kHz～30 MHz容性电压探头设计

Design of 150 kHz～30 MHz Capacitive Voltage Probe

为满足复杂电子系统的工作中无损电压测量需求,依据GB/T 6113.102-2018,研制了容性电压探头,探头工作频率150 kHz^30 MHz,检测电压范围10 mV^10 V。介绍电压探头的结构和工作原理,根据指定的分压系数和阻抗要求设计了同轴电极和阻抗变换电路。实测结果表明:容性电压探头输出电压平坦性在0.5 dB以内;被测线缆位置偏移4 mm以内,S21的测试误差小于1 dB;探头输出电压线性度较好。

In order to meet the requirements of non-destructive voltage measurement in the work of complex electronic systems, a capacitive voltage probe has been developed according to GB/T 6113.102-2018. The probe operating frequency is 150 kHz^30 MHz, and the detection voltage range is 10 mV^10 V. The structure and working principle of the voltage probe are introduced. The coaxial electrode and impedance conversion circuit are designed according to the requirements of voltage dividing coefficient and impedance. The measured results show that the output voltage flatness of the capacitive voltage probe is within 0.5 dB;when the measured cable position offset is within 4 mm, the test error of S21 is less than 1 dB;the linearity of the probe output voltage is good.