Improved Mechanically Controlled Variable Capacitors for Impedance Tune / 8,919,861

Tuesday, December 16, 2014

Mechanically short multi-carriage impedance tuners use meandering slabline structures. The meandering structure reduces the overall tuner length by a factor of 2.5 at 0.4GHz. The critical issue of slabline bends is addressed with several low loss, low reflection alternatives. A preferred configuration comprises a vertical-horizontal slabline transition. Cable connections are discarded because of reflections and insertion loss. Measured results show acceptable performance. The tuner is mostly interesting for relatively lower microwave frequencies, such as 1GHz.