Envelope Tracker Switch Pairs for Low-Inductance Bias Transitions

The patent applies magnetic field cancellation by configuring current loops to generate opposing magnetic fields that neutralize each other. This counteracts the parasitic inductance effects, enabling faster bias voltage switching without excessive power dissipation. The opposing magnetic fields from symmetrically arranged current loops create a net reduction in parasitic inductance, directly resolving the contradiction between switching speed and energy loss.

The patent employs asymmetric switching strategies where different switching sequences are applied to the paired switches in each current loop. By controlling the switches in a specific asymmetric sequence, the circuit optimizes the cancellation effect during transitions, minimizing overshooting and ringing while maintaining fast switching speeds. This asymmetric control approach fine-tunes the magnetic field cancellation to achieve optimal performance.

The patent merges multiple current loops into a symmetric configuration where their magnetic fields cancel each other. By combining the loops in a balanced arrangement with opposing orientations, the circuit achieves net magnetic field cancellation, reducing parasitic inductance and improving RF signal integrity. This merging approach maintains relatively simple circuit topology while achieving the desired electromagnetic cancellation effect.

The patent converts the potentially harmful magnetic fields generated by current loops into a beneficial cancellation effect. By deliberately arranging current loops to produce opposing magnetic fields, the circuit transforms what would normally be parasitic inductance into a useful cancellation mechanism. This approach improves RF signal integrity by turning the magnetic field generation from a harmful effect into a beneficial cancellation feature.

The patent uses magnetic field cancellation to counteract the parasitic inductance that causes overshooting and ringing during fast transitions. By arranging current loops to generate opposing magnetic fields, the circuit neutralizes the inductive effects that would otherwise degrade signal quality during rapid envelope tracking. This allows fast switching without the harmful oscillations that typically accompany high-speed transitions.

The patent introduces symmetric current loop configurations as an intermediary mechanism between the switching elements and the RF signal. These loops act as mediators that cancel parasitic inductance effects, allowing fast switching to occur without directly transmitting the harmful inductive transients to the RF signal. The current loops serve as an intermediate stage that cleans up the switching transitions before they affect the output signal.