Adjustable coilform for variable inductance

摘要

Methods and apparatus are disclosed for a tunable inductor. A coil of electrically conducting material is wrapped around a coilform, preferably generally cylindrical in shape. The coilform is constructed having a threaded portion of screw-like ridges with troughs between the ridges. The coilform may also have an unthreaded portion. The ridges and troughs of the threaded portion may run along substantially all of the coilform or just a portion of the coilform. As the coilform is rotated, the electrical conductor is engaged in the threads, changing the shape of the coil, and thereby also changing the inductance of the coil.