Patent ID: 6937117

Claim:
A high-frequency device comprising: a dielectric substrate with a first and a second surface; a filter element having a microstrip line structure, including a plurality of resonating elements made of a first superconductor film on said first surface of said dielectric substrate; a dielectric plate having a third and a fourth surface, said third surface of said dielectric plate facing at least a part of said plurality of resonating elements, said dielectric plate being substantially in parallel with said first surface, wherein when a maximum value and a minimum value of a spacing between said third surface of said dielectric plate and a surface of said first superconductor film is L and S respectively, a value of an expression 2×(L−S)/(L+S) is 0.3 or less; and a spacing adjusting member configured to control a spacing between said third surface of said dielectric plate and said first surface of said dielectric substrate.