All-pass filters based on CCII− and CCCII−

This paper proposes a first-order all-pass filter using one negative type second-generation current conveyor (CCII?), two resistors and a capacitor. From the proposed CCII? based filter, by replacing the CCII? and a resistor by a negative second-generation current-controlled conveyor (CCCII?) a new filter is developed which requires only one each of CCCII?, capacitor and resistor. The experimental and simulated results are found in good agreement with theoretical analysis. The circuits are also analyzed for non-ideal current conveyors to show that they still function as all-pass filters but with slight altered values of gain and phase.     

Estimation of autoregressive fading channels based on two cross-coupled H ∞ filters

This paper deals with the on-line estimation of time-varying frequency-flat Rayleigh fading channels based on training sequences and using H _∞ filtering. When the fading channel is approximated by an autoregressive (AR) process, the AR model parameters must be estimated. As their direct estimations from the available noisy observations at the receiver may yield biased values, the joint estimation of both the channel and its AR parameters must be addressed. Among the existing solutions to this joint estimation issue, Expectation Maximization (EM) algorithm or cross-coupled filter based approaches can be considered. They usually require Kalman filtering which is optimal in the H ₂ sense provided that the initial state, the driving process and measurement noise are independent, white and Gaussian. However, in real cases, these assumptions may not be satisfied. In addition, the state-space matrices and the noise variances are not necessarily accurately estimated. To take into account the above problem, we propose to use two cross-coupled H _∞ filters. This method makes it possible to provide robust estimation of the fading channel and its AR parameters.     

Design of UWB monopole antenna with dual notched band characteristics by using π-shaped slot and EBG resonator

In this paper, we propose the design of coplanar waveguide (CPW) ultra-wideband (UWB) dual notched band monopole antenna with a π-shaped slot and EBG is proposed. The designed antenna produces an impedance bandwidth of 2.7–11.7 GHz (VSWR < 2), except with 3.4 GHz (3.3–3.7 GHz) for S-band WiMAX application and 6.9 GHz (6.5–7.2 GHz) for C-band IEEE INSAT applications. Here, the lower and upper notches are realized by proposing a π-shaped slot on the radiating element and an electromagnetic bandgap structure as a resonator integrated on either side of the ground plane. Meanwhile, the impedance over a frequency range and current distribution are also plotted for the proposed design. The antenna prototype is fabricated and characterized experimentally for validation purpose. Fair matching is observed among the simulated and measured results.     

Design of a 1 × 2 novel optical switch based on polarization converters and splitters

In this paper, a 1?×?2 optical switch based on two TE/TM polarization converters, one 1?×?2-polarization beam splitter and a hybrid 2?×?2-polarization beam splitter/combiner is designed and discussed. The novelty of this work resides in the design of a 2?×?2-hybrid polarization beam combiner/splitter, operating as a 2?×?2 polarization optical switch through the combining and the splitting of polarized signals issued from two TE/TM polarization controllers. The novel hybrid splitter/combiner can route an optical signal either to a bar or a cross port with an extinction ratio higher than 90 dB, thanks to the feature of polarization splitting used in this device to suppress undesired polarization states and minimize the polarization-dependent loss. We have used polarization beam converters to switch between two orthogonal modes in order to facilitate the routing of these signals through the 2?×?2-hybrid polarization splitter/combiner. We changed the polarization states of signals, in our simulation via OptiSystem, through polarization controllers, by modifying only their phase shifts between 0 rad and π rad. The proposed 1?×?2 optical switch presents an average insertion loss of 3.5 dB.

     

A microstrip wideband bandpass filter based on λ/2 stub with spurious passband suppression scheme

In the design of bandpass filters, the use of λ/2 stubs of shunt configuration had been mostly unacceptable due to their effect of narrow stopband bandwidths in the ensuing filters. The design of bandpass filter presented in this article introduces 360° series transmission line segments to increase the stopband bandwidths to an acceptable level without affecting the wide passband. This designed filter has low insertion loss of less than –1.98 dB and a fractional bandwidth of 50% at 6 GHz mid-band frequency. A sharp rejection in the stopband is observed. To further widen the bandwidth of stopbands, a series capacitor and a shunt stub are used. The transmission line model of the filter is in good agreement with measured results. The filter is planar and is fabricated on FR-4 substrate which makes it cost-effective and easy to fabricate.     

Design and simulation of novel TLG–SET based configurable logic cells

Single electron tunneling circuits seem to be promising candidates as basic circuit elements of the next generation ultra-dense VLSI and ULSI circuits for their ultra-low power consumption, ultra-small size, and rich functionality. In this paper, design and simulation of novel configurable logic cells (CLCs) using single electron tunneling (SET) technology based threshold logic gate (TLG) are presented. The proposed CLC can realize all Boolean logic functions by configuring the control bits without changing the structure of the circuit and the parameters of TLG–SET based design. The logic operation of the circuit is simulated using Monte Carlo simulation. According to the simulation results, the circuit operation based on the transfer of single electrons between adjacent islands is stable.     

A novel 2.2 Gbps LVDS driver circuit design based on 0.35μm CMOS

This paper presents a novel high-speed low voltage differential signaling(LVDS) driver design for point-to -point communication.The switching noise of the driver was greatly suppressed by adding a charge/discharge circuit and the operating frequency of the circuit was also increased.A simple and effective common-mode feedback circuit was added to stabilize the output common-mode voltage.The proposed driver was implemented in a standard 0.35μm CMOS process with a die area of 0.15 mm~2.The test result show...     

New semi-conducting rotaxane based on β-cyclodextrin and anthracene moieties

A new rotaxane (BPAAn/β-CD), consisting of an anthracene-based semi-conducting material (BPAAn) encapsulated into β-cyclodextrin (β-CD), has been synthesized via the Williamson reaction in solvent-free conditions. The supramolecular structure of the compound was confirmed by NMR and FT-IR spectroscopies. The optical and morphological properties of this organic material were investigated by UV–visible absorption, photoluminescence spectroscopy and atomic force microscopy. BPAAn/β-CD film has an optical gap of 2.9 eV and exhibits green photoluminescence. An optical gap of 2.9 eV was estimated from the absorption edge of the rotaxane thin film. The BPAAn/β-CD exhibits a blue photoluminescence in dilute solution; whereas, a green emission was observed in the solid state, due to the π–π interaction in the anthracene moieties. The rotaxane shows a significantly enhanced PL quantum yield and improved film quality in comparison with the free BPAAn. The HOMO and LUMO levels were estimated using cyclic voltammetry analysis, and show enhanced electron affinity of the BPAAn in its complexed form. A single-layer device with the configuration [ITO/rotaxane/Aluminum] has been elaborated and showed low turn-on voltage of 5 V.     

Human–robot interaction based on gesture and movement recognition

Human–robot interaction (HRI) has become a research hotspot in computer vision and robotics due to its wide application in human–computer interaction (HCI) domain. Based on the explored algorithms of gesture recognition and limb movement recognition in somatosensory interaction, an HRI model of a robotic arm is proposed for robot arm manipulation. More specifically, 3D SSD architecture is used for the location and identification of gesture and arm movement. Then, DTW template matching algorithm is adopted to trace the dynamic gestures. The interactive scenarios and interactive modes are designed for experiment and implementation. Virtual interactive experimental results have demonstrated the usefulness of our method.     

Design and analysis of firewall-penetrated scheme based on trusted host

On the basis of various firewall-penetrated technologies, a novel firewall-penetrated technology based on trusted host, which can realize the communication between penetrating host and protected host, is proposed in this paper. Meanwhile, the firewall-penetrated evaluating model and its formalized statement is also proposed by quantizing penetrated level, penetrated quality, and penetrated hiding. Finally, the firewall-penetrated technology based on trusted host is analyzed under the firewall-penetrated evaluating model, and the experimental results show that this technology has obvious penetrating effect and high penetrating quality.     

Mitigation of channel estimation error in TR–UWB system based on a novel MMSE equalizer

The time reversal (TR) technique combined with the ultra-wideband (UWB) system offers a new potential for decreasing the cost and complexity of the UWB receivers. In spite of TR–UWB's good performance in perfect channel state information (CSI), it is very sensitive to the channel estimation error. The effect of channel imperfection on the TR–UWB system is considered in this paper. At first, based on a minimum mean square error (MMSE) equalizer receiver, a prefilter is calculated in closed form to improve the performance of the TR–UWB system in an imperfect CSI scenario. Furthermore, for comparison purposes, a similar calculation for prefilter is carried out based on a simple matched filter (MF) receiver. Then, in order to improve the MF receiver performance, a two-stage iteration-based algorithm is developed. The initial value for this iteration-based improved algorithm is considered to be a prefilter which is calculated in the TR–UWB system with MMSE equalizer. This optimized algorithm causes the channel estimation error in the TR–UWB system to become zero in some steps. Finally, exhaustive simulations are done to demonstrate the performance advantage attained by the improved algorithm.     

QSM-IDM – A novel quadrature spatial modulation based on interleaving division multiplexing for multiple antenna system

Quadrature Spatial Modulation (QSM) is a high spectral efficiency Multiple-Input Multiple Output (MIMO) technique used to improve the spectral efficiency of wireless communication systems. The main concept of QSM is to extend the spatial constellation of the conventional Spatial Modulation (SM) in both the in-phase and quadrature components of the data symbol. In this paper, because QSM-based on Interleaving Division Multiplexing (IDM) has not been introduced in the literature as a multiple antenna system, we introduced a novel scheme, called QSM system based on Interleaving Division Multiplexing (QSM-IDM). The antenna sets are also applied to a spreader, before being used to assign an antenna number for information transmission. Analysis and simulations for a flat fading channel show that the proposed QSM-IDM method significantly outperforms the original QSM system with the same data rate, while maintaining a relatively acceptable complexity. The obtained simulation results show that the conducted analysis yields significant improvements for the accuracy of the proposed scheme, with satisfactory complexity.     

A novel scheme to suppress the third-order intermodulation distortion based on dual-parallel Mach–Zehnder modulator

A scheme to enlarge the spurious free dynamic range (SFDR) of the microwave photonic link is proposed based on a dual-parallel Mach–Zehnder modulator (DPMZM). By properly adjusting the phase of the RF signals and the bias voltages of the DPMZM, the second-order spurious components in the optical carrier band (OCB) of the two sub-MZMs can be canceled out completely, and the third-order and fifth-order spurious components in the first-order upper sideband (1-USB) produced by one sub-MZM have equal amplitude but \(180{^{\circ }}\) phase difference with the other sub-MZM. Therefore, as the two optical beams are combined at the output of the DPMZM and the OCB and the 1-USB are abstracted by a bandpass filter to generate the transmitted signal, all the major optical spurious components that contribute to the third-order intermodulation distortion (IMD3) are canceled out. Theoretical analysis and simulation results show that the proposed scheme, without digital linearization and other optical processor, can suppress IMD3 approximately 30 dB and improve the SFDR by \(18~\hbox {dB}\,\hbox {Hz}^{2/3}\) compared with the conventional quadrature biased MZM system.     

Research and design of wap service system based on MISC platform

1 Introduction With the introduction of high mobile handsets with increasingly powerful functions and the applications of WAP2.0 with considerably novel technologies, a series of diverse hot WAP services have come into being and have been successfully lau…