Broadband Mechanical Intermodulation Tuner Using Reconfigurable Distributed Nonlinearity

Abstract

A broadband intermodulation (IM) tuner using reconfigurable nonlinearity to generate tunable IM magnitude and phase reference is proposed and demonstrated in this work. The IM-tuning mechanism is based on changing the physical positions of nonlinear source in the cavity transmission field line. In this design, the high-density electromagnetic (EM) field is optimized to be focused around the center of the transmission line; by regulating the position of nonlinear reactor (NR) in this EM field, the IM phase and magnitude can all be adjusted. By tolerance design principle, the port reflection of the transmission line can always keep stable although in different NR positions. The experiment proves the IM tuning can reach more than 65 dB in magnitude and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\pi $ </tex-math></inline-formula> in phase from 700 to 2700 MHz, while the minimal IM level is below −112 dBm at 2 dBm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times43$ </tex-math></inline-formula> dBm and the finest IM magnitude and phase resolution reach 0.1 dB and 1°, respectively. The tunable IM reference can serve for the IM measurement on passive devices and also work as an IM calibrator and mitigator for IM test and suppression in whole S band.