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Why voltage gain decreases at high frequency in case of a transformer coupled amplifier?
Wiki User
∙ 13y ago
Depends on the elements used in the circuit.
1.At Low frequency: The coupling capacitors are used to isolate the AC input and output from DC bias conditions for active devices. These capacitors with the input and output impedance of the active device act as a high pass RC filter, hence the gain falls.
2. At High Frequency: The frequency is high, but not as high as the microwave frequencies. There are two reasons
a>The capacitance of connecting wires are connected in parallel the i/p and o/p. When a capacitor is connected in parallel it acts as low pass filter, hence the voltage gain falls. This is when the frequency is high but not high as microwave frequencies.
b> The parasitic capacitance's of the active device are connected in parallel with the i/p and o/p terminals. They along with the device impedances act as low pass filter.
Wiki User
∙ 11y ago
Wiki User
∙ 14y agoBoth capacitors and inductors react different to different frequencies; also, a circuit can have undesired capacitance and inductance. In an effort to cover the greatest range of frequencies possible, the amplifier circuit would probably be designed so that it works best at medium frequencies.
Wiki User
∙ 13y agoA: Limitation of components and parasitic influences
Wiki User
∙ 13y agobecause we have the effect of the negative feedback
Wiki User
∙ 11y agoBecause of the inherent capacitance of the circuit.
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What is a direct coupled amplifier?
Quite simply, it's an amplifier wherein the stages as set up so that the output of one stage is coupled directly into the input of the next stage without any wave shaping or tuninig components between them. This makes for fairly flat frequency response. A link is provided to the Wikipedia article on direct coupling.
What is intermediate transformer?
I suspect you mean an "Intermediate Frequency transformer", or IF transformer. Superheterodyne (Or superhet) receivers convert the frequency of an incoming signal to a special frequency called the "Intermediate Frequency" or "IF". Most of the amplification takes place in the IF Amplifier which usually has several stages. Each of these stages is coupled to the next stage by a tuned transformer called an IF transformer. For AM receivers, the Intermediate frequency is usually 455 KHz, and for FM receivers it is usually 10.7 MHz. These transformers are usually about 20 turns of Litz wire on a plastic former with a dust-iron adjustable core. It sits in a little metal shield can.
Why transformer coupled amplifier is more efficient than RC coupled amplifier?
an RC coupled amplifier is basically used for voltage amplification , where the circuit currents are quite low. higher currents & voltages would mean more dissipation in the load resistors , which is essentially very lossy . The coupling amplitude to the next stage is ideally the same as the previous stage signal excursion. However if a transformer is used for coupling , both large voltages & current can be handled without incurring the dissipation of a resistive load. Moreover a coupling gain of the transformer primary to secondary ratio is also a bonus. also because of the possiblity of correct impedance matching on the primary & secondary side maximum power coupling is obtained. hence transformer coupling is more efficient in such applications. in high frequency applications transformer coupling , along with tuned circuits as applicable is the choice circuit.
Why you need RC coupled amplifier?
Rc coupled amplifier is used where good frequency response required. in case of multistage amplification system,To prevent resistance of one stage to come in parallel with next stage, it is used. we use capacitor as a coupling element between two consecutive stages.
Increasing the capacitance of the coupling capicitor in an RC coupled amplifier has what effect?
the circuit will pass waves of a lower frequency
Why gain is fall at high frequency in r-c coupled amplifier?
The gain of an r-c coupled amplifier falls at high frequency because the capacitive reactance of the capacitor tends to zero.
What is a transformer-coupled class A amplifier?
A transformer-coupled class A amplifier is just what it says it is. You'll recall that a class A amp is one that has an output that varies through all 360 degrees of an input signal. As regards the manner in which the signal is coupled to or from the stage, a transformer is used, complete with the non-linearity that it will introduce because of the characteristics of the (untuned) inductive component.
Frequency response curve of RC coupled amplifier?
at low frequency less than 50hz the voltage gain decreases with decreasing frequency and at mid frequency{50hz to 20khz} the voltage gain is uniform because resistor value are independent of frequency change and at the high frequency votage gain falls.
What is a direct coupled amplifier?
Quite simply, it's an amplifier wherein the stages as set up so that the output of one stage is coupled directly into the input of the next stage without any wave shaping or tuninig components between them. This makes for fairly flat frequency response. A link is provided to the Wikipedia article on direct coupling.
Working of Rc coupled amplifier using negative feedback?
As gain increases bandwidth decreases.
What is intermediate transformer?
I suspect you mean an "Intermediate Frequency transformer", or IF transformer. Superheterodyne (Or superhet) receivers convert the frequency of an incoming signal to a special frequency called the "Intermediate Frequency" or "IF". Most of the amplification takes place in the IF Amplifier which usually has several stages. Each of these stages is coupled to the next stage by a tuned transformer called an IF transformer. For AM receivers, the Intermediate frequency is usually 455 KHz, and for FM receivers it is usually 10.7 MHz. These transformers are usually about 20 turns of Litz wire on a plastic former with a dust-iron adjustable core. It sits in a little metal shield can.
Is the Audiosource amp310 a direct coupled amplifer?
An Audio source amp310 is a direct two channel amplifier. It runs off of hundred and fifty power watts and has two channel output transformer less direct coupled idge type amplifier.
Why transformer coupled amplifier is more efficient than RC coupled amplifier?
an RC coupled amplifier is basically used for voltage amplification , where the circuit currents are quite low. higher currents & voltages would mean more dissipation in the load resistors , which is essentially very lossy . The coupling amplitude to the next stage is ideally the same as the previous stage signal excursion. However if a transformer is used for coupling , both large voltages & current can be handled without incurring the dissipation of a resistive load. Moreover a coupling gain of the transformer primary to secondary ratio is also a bonus. also because of the possiblity of correct impedance matching on the primary & secondary side maximum power coupling is obtained. hence transformer coupling is more efficient in such applications. in high frequency applications transformer coupling , along with tuned circuits as applicable is the choice circuit.
Which amplifier has largest bandwidth?
Direct coupled amplifier
Is the audio-source 310 amp direct-coupled?
No. It uses triple-Darlington amplifier stages, and has a rated frequency response only down to 10Hz. It cannot amplifier 0Hz (DC) inputs.
Why you need RC coupled amplifier?
Rc coupled amplifier is used where good frequency response required. in case of multistage amplification system,To prevent resistance of one stage to come in parallel with next stage, it is used. we use capacitor as a coupling element between two consecutive stages.
What is meant by RC coupled amplifier?
an amplifier, where the resistor and capacitor get coupled to provide high oscillations hence by which amplifications increases at high degrees
