Beam Steering by Means of Harmonic Injection Locking

Electrically controlled beam steering requires mutually phase-locked oscillators. In this work, a free running first harmonic oscillator with a 12 GHz fundamental oscillation and a 24 GHz output signal is presented. For beam steering purposes we investigated the injection locking mechanism at the first harmonic via the antennas. Nine oscillators were mutually phase locked by means of coupling structure integrated in the antennas. Beam steering is achieved by injection locking of the oscillators at the ends of this phased array to a reference source. This combination of high output power due to the power combining of several oscillators with simple electronic beam steering and phase-locking to a moderate powered reference source is very advantageous for low-cost radar systems.