Compact edge coupled filter

A band pass filter circuit for microwave frequencies, comprising:

• a dielectric substrate having first and second opposed planar surfaces;
• a ground plane formed on the first substrate surface;
• a plurality of parallel-coupled resonators formed on the second dielectric surface, the resonators arranged in a staggered arrangement about a linear filter axis with gaps between ends of alternate resonators to provide edge coupling between alternate resonators.

An RF circuit, comprising:

• a housing structure defining a conductive channel;
• and
• a band pass filter circuit disposed in said housing structure for passing RF signals in a frequency pass band and attenuating RF signals outside said pass band, the filter circuit comprising a first input/output (I/O) port, a second I/O port, a plurality of parallel-coupled resonators formed in a planar transmission line medium comprising a dielectric substrate and coupling the first I/O port and the second I/O port, the resonators arranged for signal coupling between alternate resonators in the form of transmission line gaps.