Monolithic Microwave Nonlinear Phase Shifter

A microstrip-based microwave phase shifter that includes a thin Fe film as the active element was designed and fabricated. The device is a monolithic microwave structure that is lightweight and can be integrated on a semiconductor chip. At a fixed frequency, a large change in the phase, , was observed as the power was varied. For 1GHz below the resonance frequency, the maximum power-dependent phase shift is δφ = 55°, and for 1GHz above the resonance frequency the maximum phase shift is δφ = 74°. The experimental results show three different regimes: 1) a linear regime for powers up to 6.3 mW, 2) a stable nonlinear regime for power levels from 6.3 mW to about 1W, and above this, 3) an unstable nonlinear regime. The second regime can be used for microwave signal processing.