A new type of variable coaxial, low frequency capacitor uses two cylindrical blocks, which are interdigitally insertable into each-other to create an adjustable capacitance. Each block is made using a conductive (aluminum, brass or copper) strip which is mounted vertically on a conductive basis and is wound in spiral form around a centre axis. The blocks are guided coaxially into each-other and the relative orientation angle allows approaching the surfaces of the conductive strips from a maximum distance, which is half the width of the spiral gap, to full galvanic contact. The block penetration is motor controlled and a cascade of three or four such capacitors and associated lengths of coaxial cable is used to make wideband impedance tuners operating in the low MHz frequency range.
Application Number: 14/454,006
Filling Date: 7 August 2014 (priority 8 August 2013)
Allowed: January 20, 2016