TEM band pass filter having an evanescent waveguide

A band pass filter comprising:

• a first half-wave (λ/2) TEM mode resonator constituted by a first dielectric block having a first open end at the first side surface, a second open end at the second side surface opposite to the first open end, an input terminal formed on the second side surface, and metal plates formed on top and bottom surfaces which are opposite to each other and on third and forth side surfaces which are opposite to each other,
• a second half-wave (λ/2) TEM mode resonator constituted by a second dielectric block having a first open end at the first side surface, a second open end at the second side surface opposite to the first open end, an output terminal formed in the second side surface, and metal plates formed on top and bottom surfaces which are opposite to each other and on third and forth side surfaces which are opposite to each other,
• an evanescent E-mode waveguide interposed between the first open end of the first half-wave (λ/2) TEM mode resonator and the first open end of the second half-wave (λ/2) TEM mode resonator,
• and wherein the first half-wave (λ/2) TEM mode resonator, the second half-wave (λ/2) TEM mode resonator and an evanescent waveguide are a single unit.