UHF-Printed Monopole Filtenna for Partial Discharge Detection with LTE Signal Suppression

External partial discharge (PD) sensors for the ultra-high frequency (UHF) method are widely used to detect the PD signals in high-voltage power equipment for ease of installation and maintenance. However, conventional external PD sensors detect not only PD signals but also LTE signals; thus, a microwave filter is usually employed. In this work, a UHF filtering antenna (filtenna) is proposed as the external PD sensor to detect PD signals and simultaneously block LTE-band signals. The proposed UHF filtenna is the printed monopole antenna with a built-in interdigital bandpass geometry, which is selected for its compact size. Measurement results show that the proposed UHF-printed monopole filtenna operates adequately in the frequency range of 1 GHz to 1.6 GHz and simultaneously blocks LTE signals significantly.