Patent ID: 7319371

Claim:
A resonator filter structure on a substrate to provide a passband defined by a center frequency f C , a lower cut off frequency f L , and an upper cut off frequency f U , the resonator filter structure comprising: an input port; an output port; and a lattice type filter section between the input port and the output port, the lattice type filter section comprising: first resonator elements arranged in series branches as series arms having a resonance frequency f X1R and an anti-resonance frequency f X1A ; second resonator elements arranged in lattice branches as lattice arms having a resonance frequency f X2R and a anti-resonance frequency f X2A , wherein all of said resonator elements within said lattice type filter section have substantially equal resonance frequencies and substantially equal anti-resonance frequencies; and means for tuning at least one of said anti-resonance frequencies or one of said resonance frequencies of the resonator elements, wherein the means for tuning at least one of said anti-resonance frequencies comprises a capacitance C connected to each of said resonator elements.