The study of stripline resonators and oscillatory circuits interacting through a thin metal layer

The possibility of creating bandpass filters with an ultra-wide rejection band is shown. These filters are based on resonances of odd oscillation modes of each two-conductor resonator, the stripline conductors of which are separated by a metal layer thinner than the skin layer at the passband frequencies. A thin metal layer at the frequency of an odd oscillation mode weakly absorbs and reflects microwave power, since in this case the currents in the strip conductors of the resonator have opposite directions and almost do not induce a current in the metal layer, unlike the even mode. The developed equivalent circuit on lumped elements describes the behavior of the detected effect depending on the thickness of the metal layer. The measured frequency responses of the experimental sample of two circuits on lumped elements coupled through a metal layer, manufactured in accordance with the equivalent circuit, are in good agreement with the calculated characteristics, both with and without a metal layer.