Mechanically controlled variable capacitors for impedance tuners

摘要

An improved grounding technique for mechanically adjustable rotary capacitors uses a directly grounded bronze sliding contact to effectively and continuously ground the rotating comb-like blades of the capacitor. RF measurements of the continuity and repeatability of the capacitance settings prove the suitability of the modified capacitors for using in pre-calibrated multi-capacitor MHz range impedance tuners.

主权项

1. A method for improving the RF behavior and tuning continuity of mechanically adjustable rotary capacitors,
said capacitors comprising a static set of comb-like parallel metallic blades, and a mobile set of comb-like parallel metallic blades, said sets of blades being able to overlap each-other interdigitally, without making galvanic contact, by rotating said mobile set of blades to adjust the overlapping area, said mobile set of blades being grounded and said static set of blades being insulated from ground (floating), and a conductive sliding contact connected between the edges of the rotating mobile blades and ground.