Influence to measurement level was evaluated by using three types of measurement circuit(called test board). The ratio of disturbance source voltage to current of the circuit was calculated by FDTD method and was measured by a network analyzer. The signal source whose source impedance was 50 ohm was used as the disturbance source. The measurement results agreed with the calculation results in the frequency range less than 3GHz. However, the deviation increased at higher frequencies caused by imperfection of the test board. The results also suggested that the measurement level deviation appeared at the area where the de-coupling factor was small.
（英）
Influence to measurement level was evaluated by using three types of measurement circuit(called test board). The ratio of disturbance source voltage to current of the circuit was calculated by FDTD method and was measured by a network analyzer. The signal source whose source impedance was 50 ohm was used as the disturbance source. The measurement results agreed with the calculation results in the frequency range less than 3GHz. However, the deviation increased at higher frequencies caused by imperfection of the test board. The results also suggested that the measurement level deviation appeared at the area where the de-coupling factor was small.