Piezoelectric transformer (PT) is a combination of piezoelectric actuator and transducer, which serve as the primary side and the secondary side respectively. In the present study the disk shaped (of 20 mm in diameter and 0.6 mm, in thickness), unipoled radial mode piezoelectric transformer based on modified PZT-type solid solution was custom designed and fabricated. Different input and output area ratios of the PT were studied, namely: 21, 4, 1. The electrical properties like voltage step-up ratio, output power and temperature rise were measured for PT operating at the first resonance frequency. With the driving voltage of 20 V-RMS, the 3 W output power, 165 V-RMS output voltage and temperature rise of 20 degrees C was obtained for PT with the input/output area ratio of 1. The voltage step-up ratio of 12.5 was obtained for PT with input/output area ratio of 21.