Abstract: An electronic device may be provided with a first antenna fed by a first path and a second antenna fed by a second path. A first coupler may be disposed on the first path, a second coupler may be disposed on the second path, and a feedback path may couple the couplers to a receiver. A low-pass filter may be disposed on the second path. The first antenna may transmit signals in a low band. Some of the signals may couple onto the second antenna. The second coupler may pass the coupled signals to the receiver. Control circuitry may generate a scattering parameter value characterizing the coupling of the signals from the first antenna onto the second antenna. The scattering parameter value may be used to determine when to switch the first antenna out of use and the second antenna into use for covering the low band.

Abstract: The present disclosure provides systems and methods for detecting leakage currents in radio-frequency (RF) ablation systems. An RF generator may be configured to disable an electrical return path from a patient to a ground terminal. The RF generator may also be configured to apply an electrical signal to an electrode that is positioned to be in proximity to target tissue of the patient. The RF generator may be further configured to measure a leakage impedance while the electrical return path is disabled and the electrical signal is applied to the electrode. The RF generator may also be configured to control RF ablation therapy based, at least in part, on the measured leakage impedance. Other features are also claimed and described.