Verification of Beam Steering Based on True Time Delay in Active Phased Array Antennas

Precise beam-steering technology is essential in active phased-array antenna systems to rapidly and accurately detect targets over a wide area. Phase-based beam steering using phase shifters has been widely adopted in conventional narrowband radar systems. However, as high-speed signal processing and high-resolution range detection have become increasingly important, the use of broadband radar systems is expanding, and research on real-time true time delay (TTD)-based beam steering is gaining momentum. Unlike phase-based methods, TTD beam steering applies time delays, rather than phase shifts, across channels to control the wavefront slope. In this study, near-field transmission measurements were conducted on an 8×8 active phased-array antenna system implementing both phase-shift and time-delay beam-steering methods. By comparing the results obtained from the two approaches, the time-delay-based beam steering method was verified to produce beam directions consistent with those of the phase-shift method, thereby demonstrating the feasibility of implementing time-delay-based beam steering at the practical system level.