A comparison between two different FPGA-based topologies of first order sigma-delta modulator

Integrating sigma-delta modulator (SDM) in FPGA causes to have quantization noise inside interested bandwidth. This paper compares and analyzes between two possible FPGA-based SDM structures which are non-noise shaper SDM and noise-shaper SDM. The difference between these two structures is in the integrator block. All other SDM constitutive components are the same for both structures. First-order noise-shaper SDM with its maximum integration for FPGA implementation is reported. The advantages of noise-shaper SDM over non-noise shaper SDM are the elimination of input peak signal error as well as the increment of input voltage range. Moreover, higher suppression in signal harmonics results in better reconstruction of input signal at the output. However, the most important outcome is the improvement of quantization noise shaping out of the interested bandwidth which results higher SNR at the output

An embedded processing of differential pulse voltammetry (DPV) data using ARM processor (LPC1768)

This paper reports an embedded system design of a digital signal processing (DSP) unit for an In-situ analyzing of electrochemical data obtained by differential pulse voltammetry (DPV) from a three-electrode cell. The system implements smoothing filter, multiple peak detection and Gaussian distribution algorithms has been developed onto ARM cortex-m3 processor (NXP LPC1768) in order for the DPV to be able of detecting and analyzing heavy metals for various applications. The DPV can be used to measure sample of concentrations and environmental monitoring without the need of personal computer (PC) or expert user. Potential scanning range of this device is between -1500mV and +1500mV within frequency range 0.1Hz - 1kHz which can be applied for several electrochemical components. The developed algorithms has been tested for measuring heavy metal samples with different concentration

Multi-band notched patch antenna for 5G applications

In this paper, a multi-band notched patch antenna designed for 5G applications is presented. The extensive mobile usage and high datarate are among the applications that push 5G technology research. The proposed antenna modified by introducing three pairs of notches to resonate additional frequency bands. The antenna operates at 27.3GHz and 49.2GHz for cellular network applications; and 60.75GHz and 75.38GHz for WiGig applications. The total antenna dimensions are 10x6.8x0.79 mm 3 . The simulated results of the proposed antenna show a total wide bandwidth of 4.1GHz at the lower bands and 7.5GHz at the higher bands. The design demonstrates a high gain at all operating bands that is suitable for 5G applications

The response of a high voltage transformer with various geometries of core joint design

The core losses in a three phase transformer can be significantly reduced by improving the core joint geometry. The researchers were applied numerous types of T-joint designs in order to reach the optimum design that can be used in three phase transformer to reduction the losses. Two types of T-joint design are presented in this paper; T-joint with 90° butt-lap design and T-joint with 45° mitered design. A 3-phase distribution transformer was simulated in 3D using Ansys Maxwell software. The core loss for a three-leg three phase transformer rated 1000 KVA and the flux density distribution are investigated. The simulation results show the core losses were increased up to 3% and the flux density was increased to reach more than 22% flux density become higher when using T-joint with 90° butt-lap design as compared with T-joint with 45° mitered design

Interfacing SAW resonators for wireless high temperature applications

In the recent year, wireless sensor has become the interest of research due to their ability to monitor remotely especially in harsh condition. Here a double surface acoustic wave (SAW) resonator system for wireless high temperature sensor application is discussed. The system also did not need any external power source to function, which made them as a passive system. In this paper, the principle of the system is discussed in detail together with simulation results. Finally, the suitable materials used to develop the system which includes the interconnection at the high temperatures are also been discussed

Design of ultra-low voltage and low-power CMOS current bleeding mixer

This paper presents an ultra-low voltage and low power current bleeding CMOS double balanced mixer targeted for ZigBee application in 2.4GHz operating frequency band. The proposed mixer uses a modified CMOS current bleeding mixer topology adapting the forward body bias design technique integrated with a NMOS based current bleeding transistor, PMOS based local oscillator (LO) switching stage and on-chip inductors to achieve ultra-low voltage headroom operation down to 0.35V. The conversion gain is further enhanced by integrating an inductor at the gate of the bleeding transistor to reduce RF current leakage. The proposed architecture is simulated and verified in 0.13μm standard CMOS technology. The RC extracted simulation result shows a high conversion gain (CG) of 16dB, 1dB compression point (P1dB) at -17.65dBm, third-order intercept point (IIP3) of -7.45dBm and a noise figure (NF) of 18dB is achieved with a power consumption of 526μW

Disturbance rejection for a 2-DOF nonlinear helicopter model by using MIMO fuzzy sliding mode control with boundary layer

In this paper, one helicopter model with two degrees of freedom (2-DOF) is controlled by fuzzy sliding mode control with boundary layer (FSMC-BL) while exposed to disturbance. The model is a nonlinear and multi-input multi-output (MIMO) system that requires a MIMO, robust, stable, and nonlinear control to reject the disturbance. These requirements have been satisfied by SMC. In this paper, boundary layer removes the chattering phenomenon and fuzzy logic tunes the switching gains of SMC control law online. The simulation results which are achieved for step and sinusoidal disturbances applied to both pitch and yaw angles, are compared with those of PID control based on linear quadratic regulator algorithm (LQR-PID). Considerable improvement in control signal and yaw angle is observed by using FSMC-BL

Analysis on magnetic flux density and core loss for hexagonal and butt-lap core joint transformers

This paper presents the results of new hexagonal configuration at the T-joint of three-phase transformer core. The proposed model is compared with previous T-joint design, Butt-lap, which is widely used at present by many transformer manufacturers. The magnetic flux density distribution and core loss of a transformer rated 1000kVA are analyzed for the two types of T-joint design. The 3D simulation are carried out by using the ANSYS-Maxwell software. The results show that the magnetic flux density of the hexagonal shape T-joint is well distributed compared to that in the Butt-lap T-joint design. The core loss for the proposed model (hexagon) T-joint indicates a reduction of more than 11 % compared to the Butt-lap T-joint design

Artificial neural network model for microwave propagation in water melon

The propagation and attenuation of microwave traversing through water melon at 2.45GHz were modeled and validated. An attenuation experiment was carried out on water melon using free space transmission technique and an Artificial Neural Network (ANN) was designed, trained and deployed for the observed data from laboratory experiments. This generated a compact system against which existing mathematical models were compared. The results in both cases were found to be in congruence

A low-power current bleeding mixer with improved LO-RF isolation for ZigBee application

This paper present a low power current bleeding CMOS mixer with high LO-RF isolation for ZigBee application. The proposed mixer uses current reuse technique with self-biased transconductance stage to increase the conversion gain while substantially reducing the DC power dissipation. A NMOS current bleeding transistor and load resistor is integrated between the RF transconductance and LO switching stage to improve the LO-RF isolation. This mixer is verified in 0.13 μm standard CMOS technology. The simulation result shows a high conversion gain (CG) of 12 dB, 1 dB compression point (P1dB) of -13.4 dBm, third-order intercept point (IIP3) of -4.3 dBm and a noise figure (NF) of 15.45 dB. The circuit consumes 664 μA current from 1.2 V power supply and LO-RF isolation is improved by 25 dB