Abstract: Waveguides in accordance with embodiments of the invention are disclosed. In one embodiment, a dual-mode circular waveguide includes a cavity, a first end wall including a first handedness-preserving metasurface positioned at a first end of the cavity, and a second end wall including a second handedness-preserving metasurface positioned at a second end of the cavity.

Abstract: Waveguides in accordance with embodiments of the invention are disclosed. In one embodiment, a dual-mode circular waveguide includes a cavity, a first end wall including a first handedness-preserving metasurface positioned at a first end of the cavity, and a second end wall including a second handedness-preserving metasurface positioned at a second end of the cavity.

Abstract: Novel quadruple-mode, dual-mode, and dual-band filters as well multiplexers are presented. A cylindrical dielectric resonator sized appropriately in terms of its diameter D and length L will operate as a quadruple-mode resonator, offering significant size reduction for dielectric resonator filter applications. This is achieved by having two mode pairs of the structure resonate at the same frequency. Single-cavity, quad-mode filters and higher order 4n-pole filters are realizable using this quad-mode cylindrical resonator. The structure of the quad-mode cylinder can be simplified by cutting lengthwise along its central axis to produce a half-cut cylinder suitable for operation in either a dual-mode or a dual-band. Dual-mode, 2n-pole filters are realizable using this half-cut cylinder. Dual-band filters and diplexers are further realizable using the half-cut structure and full cylinder by carrying separate frequency bands on different resonant modes of the structure.

Abstract: Novel quadruple-mode, dual-mode, and dual-band filters as well multiplexers are presented. A cylindrical dielectric resonator sized appropriately in terms of its diameter D and length L will operate as a quadruple-mode resonator, offering significant size reduction for dielectric resonator filter applications. This is achieved by having two mode pairs of the structure resonate at the same frequency. Single-cavity, quad-mode filters and higher order 4n-pole filters are realizable using this quad-mode cylindrical resonator. The structure of the quad-mode cylinder can be simplified by cutting lengthwise along its central axis to produce a half-cut cylinder suitable for operation in either a dual-mode or a dual-band. Dual-mode, 2n-pole filters are realizable using this half-cut cylinder. Dual-band filters and diplexers are further realizable using the half-cut structure and full cylinder by carrying separate frequency bands on different resonant modes of the structure.