We present the first prediction of lateral leakage behavior of the TM-like mode in thin-ridge SOI curved waveguides and ring resonators. A simple phenomenological model is first presented which predicts that the lateral leakage in these structures is significantly impacted by both the ring radius and waveguide width. This prediction is verified using full vectorial mode matching and finite elem...

Twisted hollow waveguides with noncircular cross sections may be considered as slow-wave structures. In a twisted waveguide, propagating radio frequency (rf) waveguide modes can have phase velocities slower than those of similar modes in a straight waveguide. This property is interesting since a twisted waveguide basically has a uniform cross section along the propagation direction. In such a w...

1. Introduction A leaky-wave line-source antenna is basically an open waveguide that supports a leaky mode (instead of a bound mode) and that therefore radiates all along its length. For use at millimeter wavelengths, various novel leaky-wave antennas were proposed, analyzed, and measured based on some low loss open waveguide designed specifically. Since these waveguides are already open, a phy...

Integrated InP polarization converters based on half-ridge structure are studied numerically. We demonstrate that the fabrication tolerance of the half-ridge structure can be extended significantly by introducing a slope at the ridge side and optimizing the thickness of the residual InGaAsP layer. High polarization conversion over 90% is achieved with the broad range of the waveguide width from...