Ultra high frequency（UHF）partial discharge detection technology has been widely used in state detection of GIS equipment

but the performance of the sensor for detection varies to restrict field application effect of this technology. To investigate the UHF sensor’s response characteristics to electromagnetic wave signal caused by partial discharge

the frequency sweeping test for the sensor was conducted based on gigahertz transverse electromagnetic cell. By injecting continuous sweeping frequency sine wave signal with constant intensity into the transverse electromagnetic cell

the UHF sensor ’s output was obtained within effective detection band

and the intensity ratio of output signal to input signal is adopted to characterize the response characteristics of the sensor. Compared with traditional pulse decomposition method and standing wave ratio method

the present method is accurate. The sensor’s response characteristic curves to the signals with different input intensity were also compared

and the result showed that this method could get more information about sensor’s detection capability

such as response ability for every frequency point

detection sensitivity

and saturation interval. This method may provide theoretical basis for further study on UHF sensor performance evaluation method.