Response bandwidth measuring device and method of capacitance type tip clearance measuring system based on variable capacitance diode

The invention discloses a response bandwidth measuring device and method of a capacitance type blade tip gap measuring system based on a variable capacitance diode, the capacitance type blade tip gap measuring system is composed of a capacitance sensor, a measuring system host and an upper computer which are connected in sequence, and the measuring system host comprises a signal demodulation module and an acquisition module. The capacitance sensor is composed of a sensor probe and a tri-coaxial cable which are connected with each other, the response bandwidth measuring device is connected with the tri-coaxial cable through an SMA connector after replacing the sensor probe, and a variable capacitance diode is adopted to simulate capacitance change caused by the fact that a blade tip of a rotating blade sweeps the capacitance sensor probe; the response bandwidth measuring device is composed of a variable capacitance diode D, a resistor R1, a capacitor C1 and a capacitor C2. Two ends of the capacitor C2 connecte