scholarly journals Optimize BJT for Small Dimensions and High-Frequency Analysis

10.29007/8jx4 ◽  
2018 ◽  
Author(s):  
Bhargavi Patel ◽  
Ketan Patel
Keyword(s):  
Frequency Analysis ◽  
High Frequency ◽  
High Frequencies ◽  
Bipolar Junction Transistor ◽  
As Doping ◽  
Parameter Variations ◽  
Junction Transistor

In this paper, we have designed Bipolar junction transistor (BJT) structure for small dimensions that are (given by SCL Chandigarh) and high-frequency analysis. The material used is pure Si material no compounds such as SiGe, SiC is used. This transistor is examined by various effect of parameter variations such as doping, height, length through simulations. In this paper, we have optimized the small BJT at higher beta (β) 96.50 dB, and high- frequencies ft 8.64 GHz and fmax 21.51 GHz using pure Si material.

scholarly journals Design and simulation of high frequency colpitts oscillator based on BJT amplifier

2020 ◽  
Vol 10 (1) ◽  
pp. 160
Author(s):  
Khalid A. Humood ◽  
Omar A. Imran ◽  
Adnan M. Taha
Keyword(s):  
High Frequency ◽  
Rapid Development ◽  
Advanced Technology ◽  
Colpitts Oscillator ◽  
High Frequencies ◽  
Bipolar Junction Transistor ◽  
Barkhausen Criterion ◽  
Junction Transistor ◽  
Very High Frequencies ◽  
Very High

Frequency oscillator is one of the basic devices that can be used in most electrical, electronics and communications circuits and systems. There are many types of oscillators depending on frequency range used in an application such as audio, radio and microwave. The needed was appeared to use high and very high frequencies to make the rapid development of advanced technology Colpitts oscillator is one of the most common types of oscillator, it can be used for radio frequency (RF), that its output signal is often utilized at the basic of a wireless communication system in most application. In this research, a Colpitts oscillator is comprised from a bipolar junction transistor (BJT) amplifier with <strong>LC</strong> tank. This design is carrying out with a known Barkhausen criterion for oscillation. Firstly, is carried out using theoretical calculation. The secondary is carried out using simulation (Multisim 13). All the obtained result from the above two approaches are 10 MHz and 9.745 MHz respectively. This result is seen to be very encouraging.

Transient Vibrations of Two-Dimensional Beam Frames at Mid- and High-Frequencies

2019 ◽  
Author(s):  
Yichi Zhang ◽  
Bingen Yang
Keyword(s):  
Frequency Analysis ◽  
High Frequency ◽  
Transfer Functions ◽  
Flexible Structures ◽  
Frame Structure ◽  
Inverse Laplace Transform ◽  
Two Dimensional ◽  
Beam Structure ◽  
Element Analysis ◽  
High Frequencies

Abstract Transient vibrations of flexible structures at mid- and high-frequencies have important applications in aerospace, civil, auto and ship engineering. In this paper, a new method is developed for the determination of the transient vibration solutions of two-dimensional beam frames in mid- and high-frequency regions. In the development, the governing equations of a beam frame structure are formulated by an augmented Distributed Transfer Function Method (DTFM), without the need for discretization and approximation. The augmented DTFM differs from the traditional DTFM in that it does not contain the singularities of subsystem transfer functions, which is crucially important in a mid- or high-frequency analysis. The proposed method delivers exact eigensolutions of a beam structure from low- to high-frequencies without numerical instability. With the platform provided by the augmented DTFM, the transient response of a beam structure can be conveniently estimated by either modal expansion or the residue formula for inverse Laplace transform. A highlight of the augmented DTFM lies in that detailed information at mid- and high-frequencies, such as local displacement, slope, bending moment and shear force at any point, can be obtained, which otherwise may be difficult with conventional methods for mid- and high-frequency analysis. The proposed method is illustrated on several examples and is computationally efficient and stable from low- to high-frequency regions. In the numerical simulation, the augmented DTFM is shown to produce more accurate results than traditional finite element analysis (FEA). The proposed method is extensible to three-dimensional beam structures.

Design and Simulation for UHF oscillator using SAWR with different schematics

2016 ◽  
Vol 1 (2) ◽  
pp. 294
Author(s):  
M M Elsherbini ◽  
M F Elkordy ◽  
A M Gomaa
Keyword(s):  
Acoustic Wave ◽  
Operational Amplifier ◽  
High Frequency ◽  
High Speed ◽  
Direct Application ◽  
Colpitts Oscillator ◽  
Bipolar Junction Transistor ◽  
Wave Resonator ◽  
Junction Transistor ◽  
Lc Tank

<p><em>Various schematics for colpitts oscillator with fixed ultra-high frequency using either LC tank circuits or one port surface acoustic wave resonator are presented. Four circuits used to achieve 433.9 MHz oscillating frequency, Two of them using NPN Bipolar junction transistor, while the others using operational amplifier with high speed, gain and accuracy. A comparison between using passive elements as a source of resonance frequency and using SAW resonator is introduced. Another comparison between using an equivalent lumped circuit instead of SAWR package in oscillator design is also introduced. Two different software tools are used to achieve the required simulation. Proteus and ADS tools are used in simulation with AC, S-parameters and hybrid simulation. This paper is considered a direct application for SAW resonators in wide bandwidth ASK Transmitter / Receiver.</em></p>

Spontaneous imbalance in the non-hydrostatic Boussinesq equations

2018 ◽  
Vol 847 ◽  
pp. 614-643 ◽  
Author(s):  
Hossein A. Kafiabad ◽  
Peter Bartello
Keyword(s):  
Energy Spectrum ◽  
Total Energy ◽  
Time Evolution ◽  
Time Scales ◽  
Frequency Analysis ◽  
High Frequency ◽  
Large Scale ◽  
Boussinesq Equations ◽  
High Frequencies ◽  
High Frequency Waves

Whereas high-frequency waves are valid solutions to the Boussinesq equations in certain limits, their amplitudes are generally observed to be small in large-scale atmospheric and oceanic data. Traditionally, this has led to the development of balance models, reducing the dynamics to only the slow subset. Their solutions, however, can spontaneously generate imbalance in the context of the full equations. To quantify this, we calculate how much energy is transferred from the balanced to the unbalanced part of a turbulent rotating stratified flow that has been initialised to remove high frequencies. We lay out an approach to derive the time evolution of the balanced modes in which their interactions with unbalanced modes are taken into account. This enables us to calculate the budget of balanced (and unbalanced) energy. Our results show that imbalance generation occurs at scales where the Froude and Rossby numbers are still small and the energy spectrum is steep. We find that the scale at which maximum imbalance is generated depends on the peak of the energy spectrum and is invariant to the strength of rotation over the range examined. The unbalanced energy, after being transferred from the balanced component of the flow at larger scales, is cascaded forward and forms a shallow energy spectrum. The steep balanced subrange of the energy spectrum and the shallow subrange cross and form a kink in the total energy spectrum consistent with observed atmospheric and oceanic data. A frequency analysis at different wavenumbers shows that the separation of time scales breaks down at wavenumbers larger than those of maximum imbalance generation, but smaller than the kink of the energy spectrum. Below these scales, there is a single turbulent distribution of frequencies.

scholarly journals A New Universal Second-Order Filter using Configurable Analog Building Blocks (CABs) for Filed-Programmable Analogue Arrays

2011 ◽  
Vol 7 (2) ◽  
pp. 83
Author(s):  
M. T. Abuelma'atti ◽  
O. O. Fares
Keyword(s):  
High Frequency ◽  
Building Blocks ◽  
Second Order ◽  
Spice Simulation ◽  
Bipolar Junction Transistor ◽  
Order Filter ◽  
Programmable Analog ◽  
Field Programmable ◽  
Junction Transistor ◽  
Analog Arrays

 In this paper, the design of a universal second-order filter using configurable analog blocks (CABs) for field programmable analog arrays is presented. The configurable blocks are capable of performing integration, differentiation, amplification, log, anti-log, add and negate functions. To maintain high frequency operation, the programmability and configurability of the blocks are achieved by digitally modifying the block's biasing conditions. Using at most four CABs, this article shows that it is possible to design a versatile second-order filter realizing all the standard five filter functions; lowpass, highpass, bandpass, notch and allpass. SPICE simulation results using practical bipolar junction transistor (BJT) parameters confirm the feasibility of using the CABs in designing second-order filters. 

scholarly journals Behaviour of a High Frequency Parallel Quasi Resonant Inverter Fitted Induction Heater with Different Switching Frequencies

2016 ◽  
Vol 6 (2) ◽  
pp. 447
Author(s):  
Avijit Chakraborty ◽  
Pradip Kumar Sadhu ◽  
Kallol Bhaumik ◽  
Palash Pal ◽  
Nitai Pal
Keyword(s):  
Induction Heating ◽  
High Frequency ◽  
Heating System ◽  
Switching Frequency ◽  
Tank Circuit ◽  
Bipolar Junction Transistor ◽  
Induction Heater ◽  
Resonant Inverter ◽  
Junction Transistor ◽  
Induction Heating System

<p>This paper investigates the behavior of a high frequency parallel quasiresonant<br />inverter fitted domestic induction heater with different switching frequencies. The power semiconductor switch Insulated Gate Bipolar Junction Transistor (IGBT) is incorporated in this high frequency inverter that can operate under ZVS and ZCS conditions during the switching operations at certain switching frequency to reduce switching losses. The proposed induction heating system responds to three different switching frequencies with providing different results. An Insulated Gate Bipolar Junction Transistor (IGBT) provides better efficiency and faster switching operations. After the complete study of the proposed induction heating system at the selected switching frequencies, the results are compared and it is decided that most reliable, efficient and effective operations from the proposed induction heater can be obtained if the switching frequency is selected slightly above the resonant frequency of the tank circuit of the resonant inverter. The proposed scheme is analyzed using Power System<br />Simulator (PSIM) environment.</p>

A New Approach to Transient Vibration Analysis of Two-Dimensional Beam Structures at Medium and High Frequencies

2020 ◽  
Vol 15 (9) ◽  
Author(s):  
Bingen Yang ◽  
Yichi Zhang
Keyword(s):  
Frequency Analysis ◽  
High Frequency ◽  
Vibration Analysis ◽  
Local Information ◽  
Two Dimensional ◽  
Transient Vibration ◽  
Beam Structures ◽  
High Frequencies ◽  
Analysis Tools ◽  
Internal Forces

Abstract Transient analysis of medium-frequency (mid-frequency) and high-frequency vibrations plays an important role in the research and development of complex structures in aerospace, automobile, civil, mechanical, and ship engineering. Low-frequency analysis tools, like the finite element methods, do not work well for mid- and high-frequency problems because they require a huge number of degrees-of-freedom and consequently costly computation, and are sensitive to material properties and boundary conditions. High-frequency analysis tools, such as the statistical energy analysis (SEA) and its variations, are unsuitable for midfrequency problems because they describe the vibrational behaviors of multibody structures in a global manner and cannot provide detailed local information about displacements and internal forces. In this paper, a new method, which is called the augmented distributed transfer function method (DTFM), is proposed for transient vibration analysis of two-dimensional beam structures at medium and high frequencies. Without the need for discretization and numerical integration, the augmented DTFM consistently delivers analytical transient solutions from low to high-frequency regions. A unique feature of the proposed method is that it can provide local information about system response, such as the displacements and internal forces of a structure, at any point and in any frequency region. Additionally, the proposed method provides a platform for model reduction, by which, a balance of efficiency and accuracy in mid- and high-frequency analyses can be achieved. The proposed method is demonstrated in numerical examples.

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