Electrical Intermodulation Tuner by Multiple Nonlinearities Superposition Using Star Topology

An intermodulation (IM) tuner with 2π rad phase and 40-dB amplitude range is demonstrated in this article. The solution is based on the coherent nonlinearities combination among three nonlinear sources connected with star topology. By combining the IM components from these three nonlinear sources with 2π/3 rad phase offset for each pair, the final output IM signal can be tuned in the whole 2π rad region. Targeted to the special IM measurement for passive devices, the minimal output IM amplitude can be adjusted to be lower than -112 dBm at 2 × 43 dBm. This article can be used as a standard source for the IM phase and amplitude calibration while the tuner can also be used to realize IM distortion product mitigation for the passive devices.