Switchgear cabinet has narrow interior space and complex structure

which is not conducive to mount the ultra high frequency（UHF）partial discharge（PD）sensor. In this paper

a miniaturized UHF dipole antenna is designed based on PCB technology and its structural parameters have been optimized

which is suitable for switchgear cabinet application. Its port characteristics

such as return loss and voltage standing wave ratio（VSWR）

have been verified by vector network analyzer. The coefficients of the PCB antenna

which expresses the relationship between output signal and electric field strength under the different frequencies

are calibrated based on the standard EM field modulated in GTEM cell. A partial discharge detecting experimental platform has been set up

using the point-plane discharge model as the partial discharge source and the pulse current detection method to measure the partial discharge quantity. The experiments of UHF signals detecting as well as time-delay testing have been performed. It is proved by experiments that the PCB antenna has low loss

great directivity and high resolution and works well in the UHF signal detection of partial discharge.