Antenna Switch Bias Circuit for Low-Harmonic Tx Mode Switching

The patent applies preliminary action by introducing a discharge path for the capacitance in the DC boost circuit that activates before or during the bias transition. This discharge path allows the capacitance to rapidly discharge its stored charge, preventing the slow charge speed that causes harmonic distortion. The discharge path is configured to be active during switching transitions, enabling the capacitance to reset quickly before the next switching cycle begins, thus maintaining low harmonic distortion while preserving the isolation characteristics provided by the DC boost circuit.

The patent applies dynamics by making the discharge path dynamically controllable rather than static. The discharge path includes a discharge control signal that is activated only during switching transitions when rapid discharge is needed. During normal operation, the discharge path remains inactive, allowing the capacitance to maintain stable bias output. During transitions, the discharge control signal activates the discharge path, enabling rapid discharge regardless of capacitance value. This dynamic approach allows the system to achieve both stability during normal operation and fast response during transitions.

The patent applies merging by integrating the discharge path directly into the existing DC boost circuit structure. The discharge path shares common elements with the bias generation path, including the same capacitance and inductor, and uses the switching signals already present in the antenna switch control. The discharge control signal is derived from the same control logic that drives the main switching transistors. This integration approach adds minimal external components while achieving rapid discharge functionality, thus improving switch control precision without significantly increasing device complexity.