The beam propagation method (BPM) used for the design of an integrated optical (IO) coupler was proposed in this paper. A modal of the IO coupler was set up in BeamPROP software that is based on the BPM, and then the modes and the bi-directional propagation in the proposed coupler were investigated. Finally, the structure and dimension of the coupler was determined.

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.

Couplers and hybrids are devices in which two transmission lines pass close enough to each other for energy propagating on one line to couple to the other line. A 3dB 90° or 180° hybrid splits an input signal into two equal amplitude outputs. A directional coupler normally splits an input signal into two unequal amplitude outputs. This terminology “directional coupler”, “90° hybrid”, and “180° ...

Abstract—In this paper, a novel wideband directional coupler using coplanar waveguide multilayer slot-coupled technique is presented and implemented. The coupler uses two coplanar waveguide lines etched on two layers and coupled through an hexagonal slot etched on the common ground plane located between these layers. Firstly, conformal mapping techniques were used to obtain analytic closed-form...

⎯An analysis of a 3 dB lumped-element directional coupler (LEDC) based on arbitrary terminal impedance is described numerically. To solve the conflicted requirement for broad bandwidth and small size in LEDC, a new structure of coupler is introduced, which can significantly improve bandwidth and whose size is only 3 cm×4 cm on the conditions of the frequency domain of 410 MHz to 490 MHz. The me...

An optical add-drop multiplexer with a gratingloaded directional coupler in silica waveguides is demonstrated. The device for this configuration has a large fabrication tolerance and is small in size. A new scheme, in which the coupling length of the directional coupler is twice the complete coupling length, enables low cross-talk for both add and drop operations. This device is polarization-in...

The design of Cyclotron CYCHU-10 has been carried out at Huazhong University of Science and Technology (HUST). Because of the low centre frequency (99MHz) of its RF system, we should choose suitable directional couplers for the RF system which is supposed to be highdirectivity and tight-structure. This paper analyzes and synthesizes kinds of directional couplers, especially microstrip structure...

This paper presents the design of a bandpass filter using directional coupler. The concept of transerval filters is applied to design of microwave filters. The directional coupler is used as a transversal filtering element. This is achieved by loading the coupled ports of the filter with open-circuited stubs. The dependence of filter characteristics on the stub lengths and impedances is demonst...