Electronic-tuning type radio-frequency tuning circuit

摘要: A radio-frequency tuning circuit includes an input transformer, and output transformer. The transformer comprises a primary coil adapted to serve as coil, secondary which pair of variable-capacitance diodes having cathodes thereof connected together are in parallel therewith form first circuit. element is second circuit, coil. transformers such manner double-tuning Q-factor the made be twice high that resonant impedance substantially equal each other.