Design of triple-band h slot patch antenna

This paper attempts to design a triple band h-slot antenna by using feed line technique. These bands cover GSM mobile phone system (0.9 and 1.8 GHz) and ISM band which is used for Bluetooth and wireless local area network bands applications. The CST microwave studio software is used as a tool for simulation. This antenna is an attractive candidate for important applications like mobile phone communication systems, mobile phone jammer application, and so on

Performance improvement of sensors response using piece-wise non-linear (PWL) A/D and pulse-width modulation (PWM) A/D techniques

Sensor generally refers to a device that measures or detects a real world condition or parameter such as temperature,- speed, pressure etc, and converts the condition into an analog or digital representation. Different methods based on varying physical properties are been employed for different parameter

DESIGN AND IMPLEMENTATION OF POTENTIOMETER-BASED NONLINEAR TRANSDUCER EMULATOR

This work attempts to design and implement in hardware a transducer with a nonlinear response using potentiometer. Potentiometer is regarded as a linear transducer, while a the response of a nonlinear transducer can be treated as a concatenation of linear segments made out of the response curve of an actual nonlinear transducer at the points of inflections being exhibited by the nonlinear curve. Each straight line segment is characterized by its slope and a constant, called the y-intercept, which is ultimately realized by a corresponding electronic circuit. The complete circuit diagram is made of three stages: (i) the input stage for range selection, (ii) a digital logic to make appropriate selection, (iii) a conditioning circuit for realizing a given straight-line segment identified by its relevant slope and reference voltage. The simulation of the circuit is carried using MULTISIM, and the designed circuit is afterward tested to verify that variations of the input voltage give us an output voltage very close to the response pattern envisaged in the analytical stage of the design. The utility of this work lies in its applications in emulating purpose built transducers that could be used to nicely emulate a transducer in a real world system that is to be controlled by a programmable digital system

Design of differential resistive measuring system and its applications

Differential resistive systems are easily designed using potentiometric sensors. They usually contain two sensing resistances and a common movable terminal. This circuit can be used to sense a number of scenario; such as the liquid level in a tank, biomedical applications in determining the expansion and contraction of the muscles, the amount of bend in a bimetallic strip, the expansion and contraction in roads and railways, cracks in building for civil application, the penetration of signal in buildings for telecommunication and communication engineering applications, the voltage level in complex circuit. Since sensors with high sensitivity and good resolution are required for industrial applications, hence the need for this cheap and affordable sensor's design. Also, their output must have linear responses, that is, the output produced should be linearly proportional to the parameters of interest [1]. This chapter deals with the design of a differential resistive measuring sensor with low cost, low power consumption, with small size and improved overall performance of the circuit implanted in human body in order to generate voltage, current whose frequency, duty cycle is proportional to the physical parameters of interes

Power supply power-supply interference in smart sensors-to-microntroller interface for biomedical signals

The effects of power-supply interference on direct sensor-to-microcontroller interfaces based on measuring the charging and discharging time of an RC circuit that includes the sensor is observed in this assignment. By analysing the RC circuit, it shows that the measurement can be corrupted because of the power-supply trigger noise. To reduce the effects another resistor has been used to get the acceptable measurement of the charging and discharging time. Finally, a new approach also proposed to reduce the effects of power-supply and from this proposed circuit it can be said that the circuit is working properly. A microcontroller during communication with external circuits (or sensors) is making use of the signal conditioning circuits, which are required for signals conversion or translations to squeeze the acquired signal into a desirable range easily acceptable for the microcontroller.The common measurement chain in data-acquisition systems has four basic blocks: sensor, signal conditioner, analog-to-digital converter (ADC), and microcontroller shown in Figure 21.1. This measurement chain can be simplified by using an oscillator circuit as signal conditioner [1-4], since its time-modulated output signal can be directly connected to the microcontroller without using an ADC [5] shown in Figure 21.2. The measurement chain can be further simplified by directly connecting the sensor to the microcontroller [6-8], without using either a signal conditioner or an ADC shown in Figure 21.3. Such an interface circuit generally relies on measuring the charging or discharging time of an RC circuit that includes the senso

Perceptual model-based information hiding in audio signals

Audio data hiding is the process of embedding information into an audio signal so that the embedded information is inseparable from it and imperceptible to the listener. Information hiding is a multi- disciplinary area that combines signal processing with cryptography, communication theory, coding theory, information theory and the theory of human auditory and visual systems where information is hided within a host signal. A data hiding system should be robust, meaning that the embedded data could be decoded from the combined signal, even if it is distorted or attacked. This paper examines information hiding in speech signals. A perceptual modelbased information hiding in speech signal is developed

Design and implementation of an inductive-based human postures recognition system

This paper describes the design and implementation of an inductive-based human postures recognition system during Muslim prayers or ‘Solat’. Inductive sensors are preferred over contact sensors as they allow remote detection of postures. An array of inductive sensors are placed underneath a prayer mat to sense four different postures namely Woquf, Rokoo, Sojod and Qood. Each inductive proximity sensor comprises of a modified inductive loop, with inner and outer loops and three capacitors. The design of the sensing circuit was simulated using both MATLAB and Multisim. Nine identical sensors, with each sensor placed on a different zone on the prayer mat, are connected in parallel to a ChipKit Max32 development board. The sensors send analog signals that are digitized by the board and sent to a PC as frequency plots. Posture identification was done by analyzing the triggered zones. Experimental results are in agreement with both the analytical and simulation results and can successfully distinguish the different postures remotely

Linearizing techniques for sensor output

Sensors are fundamental part of circuit performing measurement as well as control in various fields. They present the measured quantity in analog electrical signal which is processed to perfonn the desired operation. Most of the signal processing nowadays is in digital domain due to advantages like noise-insensitivity, more robustness, better production yield, reliability and testability. To bring all these merits into real world applications, it is desirable to convert analogue signals output of sensor into digital domain representation. But due to non-linearity of the sensor output the digital approximation of actual physical signal is erroneous and does not correspond to the actual measured quantity. This chapter discuss about various methods for linearizing the output of the sensors

Flow structures in dividing open channels: a review

The supply of water for human consumption starts with the abstraction of ‘raw’ water from various sources. Most of these facilities convey raw water by pumping it directly from rivers via lateral channels to nearby water treatment plants, but this is badly affected by debris and sediment clogging at the intake structures. Lateral intakes are actually special cases of river bifurcations, where the channel naturally divides into two different branches, each carrying part of the flow and sediment. Many researchers have completed studies on bifurcations/diversions to understand the behaviour of water flow and sediment transport. However, a complete understanding of the phenomenon, especially in relation to secondary flows and vortices, is lacking up to this day. In fact, if this can be overcome, it will greatly contribute to the fundamental study of hydrodynamics at asymmetric fluvial bifurcations as well as in optimal design of diversions. Thus, the distribution of water flow in both main and lateral channels requires further detailed investigation. A review of the current state of research is discussed in this paper, with the objective of identifying the grey areas and gaps specifically in the investigation of complex turbulent behaviour of flow structures in open channels with lateral diversions

QOS downlink schedulers in LTE towards 5G network

LTE is expected to be the dominant system used by operators in these years due to its promising solutions for achieving high capacity and data rate. However, LTE packet scheduling and distributing resources among users is still the main challenge due to unfairness and low performance which occur when allocating resources to users. In this paper, the above mentioned challenges are studied and analysed, focusing on three schedulers; they are Proportional Fair (PF), Maximum Throughput (MT) and Blind equal throughput (BET). These methods do not provide QoS to users that use different types of traffic flows. The proposed algorithm in this paper is to modify the PF scheduler in order to fulfil the QoS criteria maximizing throughput and minimizing the delay for real time service. VoIP and video have been selected as real time traffic and best effort as non-real time. LTE-Sim simulator is used to compare between the mentioned schedulers in terms of throughput, delay, packet loss ratio and spectrum efficiency