Common emitter transistor amplifier frequency response experiment
The resistance-capacitance coupling is, in short termed as RC coupling. This is the mostly used coupling technique in amplifiers. The constructional details of a two-stage RC coupled transistor amplifier circuit are as follows. The two stage amplifier circuit has two transistors, connected in CE configuration and a common power supply V CC is used. The potential divider network R 1 and R 2 and the resistor R e form the biasing and stabilization network.
We are searching data for your request:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.
Content:
Lab 3: Amplifier Frequency Response
The objective of this experiment is to design a common emitter amplifier using a bipolar junction transistor and to study the characteristics of the designed amplifier. Part of the design requirement is that the amplifier will exhibit maximum symetrica1 swing in the collector current for a stable Q-point.
Another objective of this experiment is to study the impact of various bypass and coupling capacitors on the overall performance of the common emitter amplifier. This experiment will use transistor type 2N The basic BJT amplifier circuit like the one shown in Figure 1 can be designed to exhibit various desirable characteristics. An important decision involved in designing this amplifier is the choice of the operating point Q-point.
This operating point refers to the amount of DC bias current that flows through the transistor. It also refers to the resulting DC voltages across its junctions. The Q-point of such a circuit can be placed anywhere on the DC load line, depending on the choice of the DC equivalent circuit component values. The location of the Q-point determines the distortion characteristics of the AC signal. By properly locating the Q-point, the symetrica1 peak-to-peak swing of the AC collector current can be maximized.
In general, the DC load line must bisect the AC load line in order to allow the maximum amount of symmetrical variations in I C. It is also possible to design a circuit to obtain a particular value of I CQ. In this case, the location of the Q-point determines the maximum amount of symmetrical swing of the collector current as well as the maximum amount of undistorted voltage swing in the load resistor. In this design the bias voltage between emitter and collector should be 5V DC.
The quiescent collector current is 4mA. The design should provide maximum possible voltage swing at the amplifier output. Add capacitors C1, C2, and C3 as shown in Figure 2. Make sure the positive polarity of these capacitors are connected to the higher positive voltage in the circuit.
Measure the DC bias voltages on the base, emitter and the collector. Compare the measured voltages with the design intent and calculation. Tabulate the measured versus the calculated bias voltages. Throughout the measurement of the frequency response, apply low input signal levels in the order of few milli-Volts to ensure that the output signal is not distorted.
Monitor both input and output waveforms on the oscilloscope. Plot the obtained frequency response. On the measured plot clearly indicate the lower and upper cut-off frequencies of the amplifier. What is the mid-band gain of the amplifier? Calculate the amplifier bandwidth. Change C1 to 0. Answer the following questions; What impact this capacitor has on the cut-off frequencies of the amplifier? What impact it has on the amplification bandwidth? What impact it has on the mid-band gain of the amplifier?
Why this capacitor has such an impact on the performance of the amplifier? Measure the frequency response of the amplifier. How does it compare with that obtained in 2. Why this capacitor has such an impact of the mid-band gain of the amplifier? Skip to Main Content. Introduction: The basic BJT amplifier circuit like the one shown in Figure 1 can be designed to exhibit various desirable characteristics.
Figure 1 - Circuit Diagram for the Design Problem. Figure 2 - Amplifier Circuit Under Test.
Experiment No. -1 Aim: To Plot the Frequency Response of a single
The schematic of a typical common-emitter amplifier is shown in figure 1. Miller capacitor C F is a small capacitance that will be used to control the high frequency 3- dB response of the amplifier. You can find the DC collector current I C and the resistor values following the analysis provided in your text book. Since the topology and the requirements might be slightly different than in the text, you will need to make minor modifications to the design procedure and equations. Figure 2 shows the low-frequency small-signal equivalent circuit of the amplifier. Note that C F is ignored since it is assumed that its impedance at these frequencies is very high. Figure 3 shows the high-frequency small-signal equivalent circuit of the amplifier.
Lecture 23: Common Emitter Amplifier Frequency Response. Miller s Theorem.
Amplifiers are used to increase the voltage and current of a weak signal to desired level. There are two types of amplifiers. They are given below. If you increase the current of DC signal,then the voltage will drop. DC amplifiers involves capacitors for boosting operation. AC amplifiers can increase the voltage and current both at the same time. AC amplifiers involves transistors to increase the voltage and current of weak AC signals.
Common Emitter BJT Amplifier in Proteus
This lab introduces students to the importance of frequency response when designing circuits. Students will investigate the frequency response of two amplifier circuits, one made with transistors and the other using opamps. By comparing how their frequency responses differ while still providing the same overall function, students will learn about how different input frequency ranges affect design considerations. Advanced students can challenge themselves to research high-speed opamps and compare their designs and specifications to regular opamps.
Common emitter
Amplifier is a circuit that is used for amplifying a signal. The input signal to an amplifier will be a current or voltage and the output will be an amplified version of the input signal. An amplifier circuit which is purely based on a transistor or transistors is called a transistor amplifier. Transistors amplifiers are commonly used in applications like RF radio frequency , audio, OFC optic fibre communication etc. Anyway the most common application we see in our day to day life is the usage of transistor as an audio amplifier. As you know there are three transistor configurations that are used commonly i.
Electronic devices: Amplifier Frequency Response [part 1]
Backed by a diligent team of professionals, we are engaged in offering our clients with high quality Amplifiers, which is used to increase the amplitude of the signal for clearer and louder sound. This product is widely acclaimed and is highly demanded among our clients across the country, owing to its optimal quality durability and energy efficiency. Further, our product is easily available in the market at competitive rates. Get Latest Price. View Complete Details. Features : Instrument comprises of fixed output. User Satisfaction.
The common emitter configuration is widely used as a basic amplifier as it has both voltage and current amplification. Resistors R1 and R2 form a voltage divider across the base of the transistor. The function of this network is to provide necessary bias condition and ensure that emitter-base junction is operating in the proper region.
Hi Learners, I hope you are doing good. This lesson is about implementation of one of the types of Amplifiers i. Recall that A Transistor is made by combining two diodes in required manner. Hence, It there are two types of Transistors:.
Objective: In this project, you will use the Bode Plotter to simulate the frequency response of BJT amplifiers with different device models. In this tutorial you will build and test two-stage common emitter amplifiers using different BJT devices and examine their frequency response. You will learn how to import an external device model and use it in your circuit. You will also become familiar with RF. Spice's Bode Plotter virtual instrument.
Miller s Theorem. We ll use the high frequency model for the BJT we developed the previous lecture and compute the frequency response of a common emitter amplifier, as shown below Fig. We ll exame the operation of this CE Keith W. Usg the high frequency small-nal model of the BJT discussed the previous lecture, the equivalent small-nal circuit of the CE amplifier now becomes: Fig.
Long ago I was looking for such an answer
I consider, that you commit an error.