What is barkhausen criterion, Electrical Engineering

Assignment Help:

Q. What is Barkhausen criterion? Why is the value of Ab kept slightly greater than 1?

The condition |Ab| = 1 is called the Barkhausen criterion. It implies that when |Ab| = 1, there exists an output voltage even in the absence of any externally applied signal. If |Ab| = 1, the feedback voltage is sufficient for producing self sustained oscillations. If Ab = 1 precisely, then after sometime it is found that Ab will either become lower or higher than unity. This is due to the change in the characteristics of the active devices with voltage, temperature or age. If Ab < 1, the removal of input signal source will result in dying out of oscillations. If Ab > 1, then the amplitude of the oscillations will continue to increase until clipping occurs because of saturation and cut-off causing the voltage gain to reduce.

Hence, Ab is kept slightly larger than unity so that any variation in circuit parameters may not cause Ab to become less than unity.


Related Discussions:- What is barkhausen criterion

Program counter , Program Counter (PC) It is a   16 bit  register.  It ...

Program Counter (PC) It is a   16 bit  register.  It is a memory  pointer. It stores  the memory address  of the next  byte of the program to be executed. Memory  address is of

Mainframes - introduction to microprocessors , Mainframes Computers lar...

Mainframes Computers larger than minicomputer more power  operating at very high speed  called  mainframes.  They  can processes 64  bit data.  Such computers are used  in defe

power sector economics & planning, 1.  The rejection criteria of an invest...

1.  The rejection criteria of an investment project, as evaluated from the NPV method is that NPV should be equal to zero. 2.  Technical feasibility is the only criteria to dete

What are advantages of segmentation, What are advantages of segmentation...

What are advantages of segmentation ? However because the segment register is 16 bit broad and the memory requires 20 bits for an address the 8086 appends 4 bits segment reg

Why common collector amplifier is known aa emitter follower, Q. Why a commo...

Q. Why a common collector amplifier is called an emitter follower?         When the input voltage goes through its positive half cycle, the output voltage is also seen to go th

Draw a schematic diagram of transformer connections, Q. Three single-phase,...

Q. Three single-phase, 10-kVA, 2400/120-V, 60- Hz transformers are connected to form a three- phase, 4160/208-V transformer bank. Each of the single-phase transformers has an equiv

Telecommunication, Design a low noise amplifier using an Infineon RF transi...

Design a low noise amplifier using an Infineon RF transistor BFP640. The amplifier is to be used to amplify the L2 GPS signal and so the centre frequency is 1227MHz and bandwidth 4

What is meant by biasing transistor, Q. What is meant by biasing transistor...

Q. What is meant by biasing transistor? The purpose of dc biasing of transistor is to obtain a certain dc collector current at a certain dc collector voltage. These values of c

Evaluate the current using the loop-current method, Consider the circuit in...

Consider the circuit in Figure (a), which include a controlled source, and find the current in the 5-V source and the voltage across the 5- resistor by using (a) the loop-current

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd