en Diagnostics Techniques Diagnostics Techniques Only For Articles of ELECRiS 2024 Only For Articles of ELECRiS 2024 <span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">The development of advanced diagnostic tools is critical for the effective monitoring and management of electrical insulation systems. This paper presents the development of an Ultra High Frequency (UHF) sensor designed for the detection of partial discharges (PD) within high-voltage substations. The study focuses on the sensor&rsquo;s technical development, encompassing design considerations, fabrication processes, and initial performance evaluations in laboratory settings. The engineering principles underlying the sensor design are detailed, including the selection of innovative materials that enhance sensitivity and frequency response. The sensor configuration is tailored to optimize the detection of PD signals, with adjustments made based on simulated PD scenarios. Initial testing results demonstrate the sensor&rsquo;s capability to detect a range of PD activities, showcasing its potential effectiveness in real-world applications. The sensor&#39;s performance is analyzed through a series of controlled lab experiments, which confirm its high sensitivity and broad operational frequency range. This paper not only illustrates the technical specifications and capabilities of the newly developed UHF sensor but also discusses its practical implications for improving the reliability and efficiency of PD monitoring systems in electrical substations.</span></span> Partial Discharge, UHF Sensor, Antipodal Vivaldi Antenna. 173 181 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-5521-1&slc_lang=en&sid=1 Sharulnizam Mohd Mukhtar sharul@unimap.edu.my 1800319475328460016586 1800319475328460016586 No Faculty of Electrical Engineering & Technology, Universiti Malaysia Perlis, Pauh Putra Campus, 02600 Arau Perlis, Malaysia. MUZAMIR ISA muzamir@unimap.edu.my 1800319475328460016587 1800319475328460016587 Yes Faculty of Electrical Engineering & Technology, Universiti Malaysia Perlis, Pauh Putra Campus, 02600 Arau Perlis, Malaysia Azremi Abdullah Al-Hadi 1800319475328460016588 1800319475328460016588 No Faculty of Electrical Engineering & Technology, Universiti Malaysia Perlis, Pauh Putra Campus, 02600 Arau Perlis, Malaysia.