Frequency Multiplication Techniques for Sub-Harmonic Injection Locking of LC Oscillators and its Application to Phased-Array Architectures

A frequency multiplication and phase steering technique that utilizes the injection locking phenomena of LC local oscillators (LO) is reported. The potential application of this technique to LO-path based phase-shifting in RF/millimeter-wave integrated phased-array architecture is proposed. Advantages and disadvantages of the proposed technique are discussed in reference to those of the recently reported architectures in the literature. A high-order harmonic synthesis approach is introduced at the core of the proposed frequency multiplication technique for which a mathematical formulation is provided to highlight the underlying principles and trade-offs. Architectural variations on the high-order harmonic synthesis approach are also introduced and contrasted. The proposed multiplication and phase steering techniques have been investigated and prototyped in a main stream 130-nm CMOS process. Simulation and measurement results of the prototype are provided to substantiate the proposed techniques. Measurement results include output phase noise performance of -115 and -107.17 dBc/Hz, maximum phase shift errors of 2.35- and 2.1-degrees after calibration, extracted peak-to-null ratios of > 28 dB and current consumptions of 26.8 mA and 30.3 mA at 18.31-GHz and 21.51-GHz, respectively.