High power electrically variable inductor

Claim 1

A high power electrically variable inductor comprising a Ushaped ferrite core having two arms, and a connecting member, said connecting member having first, second, and third sections with substantially reduced areas to minimize the DC magnetic field, each of said sections also having holes therethrough, a balanced RF variable inductor winding consisting of three series connected portions, each of said portions having an equal number of turns on opposite sides of the associated hole and wound on the associated section thereof, said balanced RF variable inductor winding including an input terminal for the reception of a high power RF input signal and an output terminal providing a high power RF output signal, an electromagnet attached across the ends of said two arms closing said U-shaped ferrite core, said electromagnet receiving a varying DC input signal thus operating to vary the magnitude of the inductance of said balanced RF variable inductor winding, and a shunt permanent magnet also attached to said U-shaped ferrite core biasing the ferrite material in the RF variable inductor winding region to a lower permeability.