the circuits being coupled so as to form a bandpass filter

Full Title

Continuous tuning (H03J7/00, H03J9/00 take precedence; combination of continuous and discontinuous tuning other than for bandspreading H03J5/00) > of more than one resonant circuit simultaneously, the circuits being tuned to substantially the same frequency, e.g. for single-knob tuning > the circuits being coupled so as to form a bandpass filter