Medium-bandwidth crystal filter with small voltage standing-wave ratio and parameter generation method thereof

The invention discloses a medium-bandwidth crystal filter with a small voltage standing-wave ratio and a parameter generation method thereof, and the medium-bandwidth crystal filter comprises a quartz crystal resonator which comprises two lattice networks, and each lattice network comprises a high-frequency crystal resonator and a low-frequency crystal resonator and is used for frequency control of input and output signals; the inter-stage coupling capacitor is arranged between the two lattice networks and is used for widening the passband bandwidth of the filter; the two differential connection transformer inductance coils and the two coupling capacitors are arranged on the edges of the two lattice networks respectively and used for matching lattice network characteristic impedance and terminating impedance, and the differential connection transformer is used for impedance conversion and resonance of the coupling capacitors and the inductance coils, so that the part, needing to be reserved, of an electric si