In order to overcome the shortcomings that the measuring bandwidth of small size flat capacitive divider is generally narrow

we introduce a flat capacitive sensor contains integrator and impedance converter. The flat capacitive sensor adopts small coaxial structure of which diameter is 100 mm. And the connecting segment between the flat probe and the outgoing cable hides in the shielding cavity which is convex. This could reduce the self-inductance and the interference effectively. The outgoing cable connects to the designed integrator and impedance converter

restoring the signal and optimizing the low-cut-off frequency. Through the experiment and the data analysis

the bandwidth of the flat capacitive sensor is 10 Hz

1

50 MHz

and it can be used for measuring the steep front pulse and long tail pulse.