Patent ID: 8779874

Claim:
A waveguide structure comprising: a first conductive plane; a second conductive plane continuously laid in parallel with the first conductive plane; and a plurality of unit structures, each of which includes: a transmission line having an open end, which is formed in a different layer from the first conductive plane and the second conductive plane and is positioned to face the second conductive plane; and a conductive via electrically connecting the transmission line to the first conductive plane, wherein the unit structures are repetitively aligned in a one-dimensional manner or in a two-dimensional manner, and wherein the waveguide structure is configured to suppress electromagnetic propagation between a power source and a ground plane at a frequency f satisfying an inequality Im(Y(f))≦0, where Im(Y(f)) is an imaginary component of a parallel admittance Y(f) defined as: Y ⁡ ( f ) = 1 i ⁡ ( 2 ⁢ π ⁢ ⁢ fL via - Z 0 tan ⁡ ( 2 ⁢ π ⁢ ⁢ f ⁢ ɛ eff ⁢ ɛ 0 ⁢ μ 0 ⁢ d ) ) + i ⁢ ⁢ 2 ⁢ π ⁢ ⁢ fC plane where f denotes frequency, i denotes an imaginary component meaning that i 2 =−1, L via denotes an inductance of the conductive via, C plane denotes a capacitance between the power source and the ground plane, Z 0 denotes a characteristic impedance of the transmission line, d denotes a length of the transmission line, ∈ eff denotes an effective dielectric constant, ∈ 0 denotes a dielectric constant under vacuum, and μ 0 denotes a magnetic permeability under vacuum.