A new design of coplanar waveguide (CPW)-fed antenna with circular polarization (CP) and excellent impedance matching is presented. In this design a pair of circular-shaped slits is applied to opposite corners of the slot for enhancing the impedance matching and realizes bandwidth of 134.43% across 2.98-15.20 GHz for VSWR≤2. Furthermore this structure exhibits axial ration bandwidth (ARBW) of 3...

We present the design and simulation of an ultra-compact polarization beam splitter (PBS) by combining a photonic crystal (PhC) multimode waveguide and an internal PhC section. The PhC multimode waveguide is designed to collect the powers reflected by or transmitted through the internal PhC structure which serves as a polarization sensitive scatterer. Plane wave expansion (PWE) method is used t...

New designs of all-optical logic gates based on spatial-soliton interactions in optical communication spectral regions were proposed. The proposed structures are composed of local nonlinear Mach-Zehnder interferometer (MZI) waveguide structures with multi-input ports and two nonlinear output ports. They can be used to design various all-optical logic gates. The nonlinear MZI waveguide structure...

We report a general approach to the design of broadband waveguide couplers. A double-parallel grating assembly is used to cancel the first chromatic order, and a proper choice of prism glass and base angle is made to compensate for the second chromatic order. The technique was applied to a Corning glass 7059 waveguide, and a spectral bandwidth of 70 nm was measured by the use of two complementa...

An optical modulation mechanism based on dynamically shifting the photonic potential barrier of a photonic crystal waveguide is presented. The modulation mechanism is modeled by the one-dimensional quantum tunneling effect using the Schrödinger equation. The calculation results show that the modulation efficiency is 200 times higher than that of the conventional Mach-Zehnder modulator. Based on...

Microwave-frequency signals are conveyed by using the Microstrip antennas. It is capable of dual and triple frequency operations and has light weight and low cost. Similarly, larger bandwidth can be achieved by Coplanar Waveguide (CPW) structure. Gain can be enhanced using the Defected Ground Structure (DGS). This paper presents the performance comparison of the design of a microstrip antenna a...

Abstract— This work investigates the improvement of the active reflection coefficient of waveguide-fed phased-array antenna using liquid crystal layers. The anisotropy properties of liquid crystal layer can be employed to eliminate blind scan angle and improve the wide angle impedance matching of the waveguide-fed phased array antennas. The authors have expressed the modal analysis of the waveg...

We describe a design for a sideband-separating balanced mixer using four planar single-ended mixer chips connected to the feed horn and LO source by a network of quadrature waveguide hybrids and an in-phase waveguide power divider. The mixer has separate IF output ports for the downconverted signals from the upper and lower RF sidebands, and requires ~14 dB less LO power than a single-ended mix...

A new generation of high-frequency integrated circuits is presented, which is called substrate integrated circuits (SICs). Current state-of-the-art of circuit design and implementation platforms based on this new concept are reviewed and discussed in detail. Different possibilities and numerous advantages of the SICs are shown for microwave, millimeter-wave and optoelectronics applications. Pra...