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At high frequency the capacitor coupling the stages has low reactance, therefore the net resistance of that stage is not equal to next stage, due to this poor impedance matching the power of this stage is not transferred fully to next stage and hence gain falls. And also at high frequency transistor capacitance comes into existence which provides feedback and it thus lowers gain.
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Frequency response of bjt amplifier?
All amplifier typically exhibit a band-pass frequency response. The cut off frequency in the low end is usually determined by the coupling band bypass capacitor .and the high frequency limit is typically determined by internal capacitances in the transistor itself.
What will be the change in frequency response curve of JFET if Ci and Ce are interchanged?
If the input capacitance (Ci) and the emitter bypass capacitance (Ce) are interchanged in a JFET circuit, the frequency response curve will be significantly affected. Ci typically influences the high-frequency response, while Ce primarily affects the low-frequency response by providing a bypass path for AC signals. Interchanging them may lead to a shift in the cutoff frequencies, potentially degrading the amplifier's performance and altering the gain at different frequencies. As a result, the overall frequency response curve could exhibit higher low-frequency roll-off and altered high-frequency behavior.
Which amplifier uses the base as the reference terminal for the input and output signal?
The amplifier that uses the base as the reference terminal for the input and output signal is the common-base amplifier. In this configuration, the input signal is applied to the emitter, while the output is taken from the collector. The common-base amplifier is known for its high frequency response and low input impedance, making it suitable for specific applications such as radio frequency amplification.
What is the effect of miller capacitance in CB configuration?
Miller capacitance in a common-base (CB) configuration can significantly impact the amplifier's frequency response. It effectively increases the input capacitance due to the feedback from the output to the input, which can lead to reduced bandwidth and increased response time. This effect can limit the high-frequency performance of the amplifier, making it essential to consider Miller capacitance in the design and analysis of CB amplifiers.
How do you convert low frequency to high frequency with a circuit?
You typically create a DC power supply from the low frequency, and use that to run a high frequency oscillator and amplifier. If there needs to be a relationship between frequency in and frequency out, often there is a divider running on the high frequency side in combination with a phase locked loop synching up to the low frequency side.
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.
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 high frequency tuned amplifier?
High frequency amplifier is a device which is tuned by high frequency. Tuned means the overlapping of generated frequency with that amplifier.
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
Frequency response of bjt amplifier?
All amplifier typically exhibit a band-pass frequency response. The cut off frequency in the low end is usually determined by the coupling band bypass capacitor .and the high frequency limit is typically determined by internal capacitances in the transistor itself.
Why frequency is assumed to be high while calculating stray capacitance of a single stage RC coupled amplifier?
A: Think about it if there is no frequency there is no problem. The problems becomes apparent as the frequency increases because adjacent proximity now becomes capacitors to influence the circuitry
What will be the change in frequency response curve of JFET if Ci and Ce are interchanged?
If the input capacitance (Ci) and the emitter bypass capacitance (Ce) are interchanged in a JFET circuit, the frequency response curve will be significantly affected. Ci typically influences the high-frequency response, while Ce primarily affects the low-frequency response by providing a bypass path for AC signals. Interchanging them may lead to a shift in the cutoff frequencies, potentially degrading the amplifier's performance and altering the gain at different frequencies. As a result, the overall frequency response curve could exhibit higher low-frequency roll-off and altered high-frequency behavior.
Which amplifier uses the base as the reference terminal for the input and output signal?
The amplifier that uses the base as the reference terminal for the input and output signal is the common-base amplifier. In this configuration, the input signal is applied to the emitter, while the output is taken from the collector. The common-base amplifier is known for its high frequency response and low input impedance, making it suitable for specific applications such as radio frequency amplification.
Why gain decreases at higher frequencies?
As the frequency of an amplifier increases, the gain decreases due to the capacitive reactance of the internal components. Capacitors start to act as a short circuit at high frequencies, causing the signal to bypass the amplification stage and reducing the overall gain. This phenomenon is known as the frequency response of the amplifier.
What is amplifier roll off?
A practical amplifier will contain several components of a "shunt" capacitance inherent in the transistor and physical wiring of the amplifier circuit. As the frequency of the input signal increases, the reactance of these shunt-capacitances will decrease until, at a frequency determined by the value of the shunt-capacitance and the circuit impedance, signal attenuation begins to take place. Thus the shunt capacitances limit the high-frequency response of the amplifier (note that the transistor itself also has inherent limits to it's high frequency amplifying capability). In the case of operational amplifiers, many operational amplifiers are internally compensated by a small capacitor (e.g. about 30pf for a 741). The internal frequency compensation capacitor prevents the operational amplifier from oscillating with resistive feedback.
What is a common base NPN amplifier?
A common base NPN amplifier is used for high frequency applications as the base minimize oscillations at high frequency, separates the input and output. In a common base NPN amplifier the voltage gain is high, relatively low input impedance and high output impedance compared to the common collector.
What is the effect of miller capacitance in CB configuration?
Miller capacitance in a common-base (CB) configuration can significantly impact the amplifier's frequency response. It effectively increases the input capacitance due to the feedback from the output to the input, which can lead to reduced bandwidth and increased response time. This effect can limit the high-frequency performance of the amplifier, making it essential to consider Miller capacitance in the design and analysis of CB amplifiers.
