Abstract
This paper reports the design of a compact Wilkinson power divider for use in modern wireless communication systems where circuit size is a critical constraint. The proposed design replaces the conventional quarter-wavelength transmission line with a compact phase-shifting section based on parallel-coupled microstrip lines, providing an impedance transformation factor of 2–√ for proper matching to a 50 Ω system. The power divider is designed to operate at a center frequency of 3.0 GHz on an AD260 substrate, with the phase-shifting function directly integrated into the power-dividing network to reduce the overall circuit footprint. The fabricated prototype occupies an area of 15.367×22.860mm2, corresponding to a size reduction of approximately 22% compared with a conventional Wilkinson power divider. Simulation results obtained using Advanced Design System (ADS) demonstrate strong agreement, with a return loss (S11) better than 15 dB and insertion losses (S21 and S31) close to the ideal value of −3 dB at the operating frequency. The fabricated prototype was characterized over the 2–6 GHz frequency range, demonstrating strong agreement with the simulated results. These results indicate that the proposed structure achieves effective power division with good impedance matching while maintaining a compact size, making it suitable for integration into compact RF and microwave front-end circuits.