Bandpass filter, and wireless communication module and wireless communication device using the bandpass filter

Abstract

[Object] An object is to provide a bandpass filter that can be used for a wide frequency band and has a large degree of freedom in designing a passband, and a wireless communication module and a wireless communication device that use the bandpass filter. [Solution] A bandpass filter includes first to third resonance electrodes, andsequentially arranged side-by-side such that they are electromagnetically coupled to each other, the first to third resonance electrodes, andbeing grounded at one end and constituting first to third resonators, respectively; a first input/output coupling electrodefacing the first resonance electrodeand electromagnetically coupled thereto; a second input/output coupling electrodefacing the second resonance electrodeand electromagnetically coupled thereto; and a resonator coupling electrodeconfigured to provide electromagnetic coupling between the first resonance electrodeand the third resonance electrode. The first and second resonators have the same resonance frequency which is different from a resonance frequency of the third resonator. The first to third resonators are used to produce a passband. The bandpass filter can be used for a wide frequency band and has a large degree of freedom in designing the passband.