In order to overcome the main drawbacks of coaxial, waveguide, and stripline couplers, the analysis and the design of a compact coaxial-to-microstrip directional coupler convenient for power and antenna control application, are presented using the method of moments (MoM) in two dimensions. This technique is adapted to study the complex configuration of the line’s system, which does not have a s...

A novel design for an ultracompact, high-Q notch-rejection filter is presented, and an analytic expression for the transmission properties is derived. This folded directional coupler shares the properties of a Fabry-Perot resonator and a directional coupler. We compare and contrast the device to high-Q Fabry-Perot cavities in photonic crystal waveguides.

We report on intensity-dependent switching in lithium niobate directional couplers. Large nonlinear phase shifts that are due to cascading detune the coupling between the coupler branches, which makes all-optical switching possible. Depending on the input intensity, the output could be switched between the cross and the bar coupler branches with a switching ratio of 1:5 and a throughput of 80%.

Recent experience with X-band accelerator structure development has shown the rf input coupler to be the region most prone to rf breakdown and degradation, effectively limiting the operating gradient. A major factor in this appears to be high magnetic fields at the sharp edges of the coupling irises. As a first response to this problem, couplers with rounded and thickened iris horns have been e...

One of the essential components a wireless high-power transfer system for heavy-duty electric vehicles is inductive coupler. The efficiency power strongly depends on geometric parameters coupler, which in turn have an important effect electromagnetic whole system. transmitting (Tx) and receiving (Rx) coils coupler proposed this paper Double-D planar structure are located magnetic cores made con...

Analysis and design techniques for designing a lumped-element 3-dB quadrature coupler with wide-band flat coupling are proposed for microwave integrated-circuit/monolithic-microwave integrated-circuit applications. The proposed design technique can produce a coupler with flat coupling over 50% fractional bandwidth, which is wider than the conventional lumped-element design methods. A prototype ...

A new metal mesh coupler that makes use of a tunneling effect of evanescent waves between a metal mesh and a dielectric plate, has been proposed as a quasi-optical component for millimeter and submillimeter wavelengths. Theoretical calculation and experimental measurement performed from 40 GHz to 60 GHz show that the transmittance of the coupler can be changed more than 50 % for the variation o...

We present simple and accurate relations for the study of parallel and curved tunable single-mode fiber directional couplers employing step-index or graded-index fibers. Analytical results for the various coupler parameters such as coupling coefficient, effective interaction length, tunability, and channel wavelength separation in directional coupler wavelength filters are presented. These resu...

A polarization-independent optical directional coupler based on slot waveguides is proposed and analyzed by using rigorous full-vectorial analysis methods based on a finite-element scheme. Properly choosing materials and structural parameters makes the coupling length for quasi-TE modes become equal to that for quasi-TM modes. Tolerances to operating wavelength and structural parameters are als...

A novel optical add-drop multiplexer (OADM) based on a null coupler with an antisymmetric grating was designed and experimentally demonstrated. The antisymmetric grating exclusively produces a reflection with mode conversion in a two-mode waveguide. This improves the performance compared with previous demonstrations that used tilted Bragg gratings. Our design minimizes noise and cross talk prod...