Methods for measuring high frequency voltage and current

　　1. Measurement of high-frequency voltage
　　In order to analyze the influence of the voltmeter on the measured circuit, let's study the equivalent circuit of the voltmeter. The larger the Ci of the voltmeter, the smaller the capacitance C of the loop, resulting in more severe detuning of the loop; the input resistance Ri is connected in parallel to the loop, which will change its working state. The smaller Ri is, the more obvious the change in working state is.

　　2. The electronic voltmeter used for high-frequency measurement should have the following characteristics:
　　(1) The reading has little to do with the frequency of the voltage being measured over a wide frequency band.
　　(2) It has little effect on the operating conditions of the source being measured. In other words, the input resistance should be large (the input capacitance should be small).
　　(3) The range of the measured voltage should be wide and the sensitivity should be high.
　　(4) The reading settling time should be short.
　　(5) It should have the ability to withstand overload (the voltage at the input end of the voltmeter exceeds the allowable value).
　　3. Measurement of high-frequency current

　　【example】

　　The ammeter should be connected at the lowest point, where the reaction effect of the circuit under test is minimal.