A Novel p-i-n Inductor for Tunable Wideband Matching Network Application

A tunable and wideband L network using a small-area p-i-n inductor is realized for matching circuits for the first time. The inductance required for the impedance matching can be controlled by the bias current to tune the resonant frequency of this simple L network. Meanwhile, the bandwidth of the single L network can be enlarged using the presented novel p-i-n inductor, allowing wide bandwidth to be achieved without additional L networks in cascade. The dc and RF characteristics of the presented p-i-n inductors are investigated comprehensively through measurements and our theory. The tunable L network with the p-i-n inductor is designed and implemented by the Taiwan Semiconductor Manufacturing Company CMOS technology to transform a high impedance to 50 Ω. The measured bandwidth and resonant frequency agree well with simulated results. This demonstrates that the p-i-n inductor can be applied for the tunable input matching circuits, providing the capability to minimize the impact of process variation.