This paper presents an electrically tunable phase shifter with a compact design, developed for implementing a Ku-band continuous beam-steering antenna. The proposed design is an enhanced Schiffman phase shifter, integrated with varactor diodes. By adjusting the voltages applied to the diodes, the phase shifter enables continuous tuning of the phase shift across a broad bandwidth within the Ku band. A prototype featuring a three-diode varactor-compensated phase shifter has been fabricated and experimentally validated, demonstrating effective tunability through measurement results. Analytical design methods are employed to derive mathematical expressions for the scattering parameters and phase shift behavior.