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In this paper, we have proposed a novel design and simulated an all-optical 1-bit half-adder based on photonic crystal. The fundamental structure is a square lattice of 2D Silicon rods, operating around the central wavelength of 1550 nm. The proposed half adder is composed of an optical combiner with two input ports, A and B are used for excitation power, and two parallel nonlinear ring resonators with two output ports, S and C, which are SUM and CARRY, respectively. In the creation of a nonlinear ring resonators at the resonant wavelength of 1550 nm and 1538 nm, respectively, we replaced the central rods with defect rods made of doped glass with a linear refractive index and nonlinear Kerr coefficient are about 1.4 and 10-14 m2/W. The optical intensity 10 mW/µm2 is used at the input ports A and B. The contrast ratios for output ports SUM and CARRY are about 13.71 dB, 13.67 dB and the total footprint is 198.9 µm2. The proposed structure has the advantage of simple design and small size with dimensions of 15.3×13 µm2. The normalized power values are low which correspond to 0 state in the output, whereas the power is reasonably high at output for logic stat 1, the power level for logic states "0" and "1" is equal to 4% and 94% respectively. The power difference with high and low logic values improves the constant ratios and reduce the bit error rate BER. The finite element method FEM and Plane-wave expansion PWE method are used to simulate the proposed structure under COMSOL Multiphysics software. [ABSTRACT FROM AUTHOR]

This paper demonstrates a novel form of substrate integrated waveguide SIW antenna array based on Fourier Series Equations. An optimized SIW power divider feeds the proposed structure where a micro-strip transition is used for impedance matching at 50 Ohm. The proposed antenna is traveling wave antenna type, in conventional methods the curve of antenna is of a linear or exponential form. In our method, we used the FSE to modify the contour of the antenna. The method is based on optimization of the Fourier series coefficients in order to maximize the gain for φ = π/2 and θ = π/2. The results of the return loss, the field's distribution, the radiation pattern and the realized gain were analysed. Furthermore, the antenna is designed in HFSS and CST with a comparison between them. The simulated return loss was compared with experimental measurements. The return loss of the proposed 1 × 4 antenna array is less than −10 dB at 5.5–6.8 GHz with an average gain about of 6 dBi and a peak gain about of 7.2 dBi. The proposed 1 × 4 antenna array is optimized with HFSS and designed using FR4 substrate, and considered in C-band for centimeters waves applications. [ABSTRACT FROM AUTHOR]

In this article, two compact Substrate Integrated Waveguide (SIW) bandpass filters based on Defected Ground Structure (DGS) technology are proposed. Hilbert Cell of second order is the resonator shape proposed for the DGS of both filters, where the first filter DGS consists of five pairs, and the second one uses only three pairs. The pair used in the first filter consists of two cells located side to side whereas they are placed face to face in the second filter. In order to enhance the performance of the second filter and based on the evanescent-mode technique, three other pairs of first order Hilbert cells are engraved on the top layer. Both bandpass filters are designed to operate in C band with a measured bandwidth of 1.8 GHz for the first filter and 0.86 GHz for the second one. The proposed structures have the same physical dimensions, which is 38:1mm 16mm with different measured insertion losses of 􀀀2:5 dB and 􀀀2:7 dB. Both structures exhibit an upper stopband rejection with attenuation around 􀀀20 dB and 􀀀29 dB, respectively. The filters operate in a transmission bandwidth of [5.5 GHz|7.3 GHz] and [5.27 GHz{6.13 GHz] with a fractional bandwidth (FBW) of 28.1% and 15.09% for the first filter and the second filter, respectively. A good agreement is reported between the measured and simulated results. [ABSTRACT FROM AUTHOR]

In this paper a defected ground structure (DGS) bandpass filter based on half mode substrate integrated waveguide (HMSIW) technology is proposed. We used vertical double circle complimentary split ring resonator (CSRR) as DGS etched on the top plane of the SIW cavity to constitute a multiple mode resonator and dumbbell DGS etched on the ground plane of the SIW cavity for enhance the filter performance. The taper line is used for transition between microstrip to SIW The simulation results obtained by CST and HFSS show that the proposed filter has a large transmitted bandwidth from 6.2 to 12.7 GHz. The higher simulated insertion loss is about -0.5 dB and the lower return loss is about -48 dB. The size of the designed filter is 60 × 9.8 mm2 which make it more compact compared to other published research works with a size reduction of about 50%. Good rejection are achieved under 6 GHz and upper 13 GHz. The good calculation of taper, the empirical parameters of the filter and the use many DGS cells in the bottom plane allowed us to obtain the good results. Good agreement between CST and HFSS simulation results. [ABSTRACT FROM AUTHOR]

A novel design of a double selective filter for integrated optics in two-dimensional photonic crystals operating at a wavelength of 1.31 and 1.55 µm is proposed in this paper. We focus particularly on filters transmission and selectivity enhancement. The two-dimensional photonic crystals filters are simulated by using a combination of three cascaded waveguides; these later are conceived by one missing row and with different rods radii for efficient filtering purpose. The properties of these photonic crystal structures are numerically investigated by using the two-dimensional finite-difference time-domain method and the numerical results are given for incident light wave having transverse electrical polarization. A final synthesized filter topology is presented and the maximum of transmission is found around 70% and 60% localized respectively near 1.31 and 1.55 µm wavelengths. [ABSTRACT FROM AUTHOR]