- #1
calmel
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i don't understand the difference between low ,high,midfrequency analysis of transistor amplifiers...what's midband analysis?
Anlysis of transistor amplifiers
- Thread starter calmel
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Discussion Overview
The discussion revolves around the frequency analysis of transistor amplifiers, focusing on the differences between low, mid, and high-frequency behaviors. Participants explore concepts such as midband analysis, high pass and low pass filters, and the impact of various components on amplifier gain across different frequency ranges.
Discussion Character
- Technical explanation
- Conceptual clarification
- Debate/contested
Main Points Raised
- One participant expresses confusion about the distinctions between low, mid, and high-frequency analysis of transistor amplifiers, specifically asking about midband analysis.
- Another participant explains that at low frequencies, the effects of coupling and bypass capacitors are significant, causing the amplifier to act as a high pass filter, with gain changing with frequency.
- It is noted that at high frequencies, internal capacitance of the transistor affects operation, leading to the amplifier acting as a low pass filter, again with gain varying with frequency.
- In the midband region, gain is described as almost constant, with all capacitances ignored, and gain depending primarily on passive elements like resistors, making it independent of frequency.
- A participant seeks clarification on the definitions of high pass and low pass filters, prompting further explanation.
- High pass filters are defined as circuits that allow higher frequency components to pass while blocking lower frequencies, while low pass filters do the opposite, with gain characteristics discussed in relation to frequency.
Areas of Agreement / Disagreement
Participants generally agree on the definitions and behaviors of high pass and low pass filters, as well as the characteristics of transistor amplifiers across different frequency ranges. However, there is some confusion regarding the specifics of midband analysis, indicating that the discussion remains somewhat unresolved.
Contextual Notes
The discussion includes assumptions about the behavior of amplifiers that may depend on specific circuit configurations and definitions of frequency ranges, which are not fully explored or resolved.
Who May Find This Useful
Readers interested in electronics, specifically those studying or working with transistor amplifiers and frequency response analysis.
- #2
ratn_kumbh
- 9
- 0
Frequency analysis of transistor amplifier shows behavior of amplifier at different frequency. Like at low frequency effect of coupling & bypass capacitor becomes significant. So gain of amplifier changes with freq. In this region of frequency amplifier acts as High pass filter
At high frequency internal capacitance of transistor affect the operation of amplifier.So here also gain of amplifier changes with freq. And In this region of frequency amplifier acts as low pass filter.
in the midband(i.e. between low & high frequency) Gain of amp is almost constant. All capacitances are ignored in this region. Gain depends on value of passive element(resistors). So gain is independent of frequency
At high frequency internal capacitance of transistor affect the operation of amplifier.So here also gain of amplifier changes with freq. And In this region of frequency amplifier acts as low pass filter.
in the midband(i.e. between low & high frequency) Gain of amp is almost constant. All capacitances are ignored in this region. Gain depends on value of passive element(resistors). So gain is independent of frequency
- #3
calmel
- 2
- 0
thanks!what are high pass and low pass filters?ratn_kumbh said:Frequency analysis of transistor amplifier shows behavior of amplifier at different frequency. Like at low frequency effect of coupling & bypass capacitor becomes significant. So gain of amplifier changes with freq. In this region of frequency amplifier acts as High pass filter
At high frequency internal capacitance of transistor affect the operation of amplifier.So here also gain of amplifier changes with freq. And In this region of frequency amplifier acts as low pass filter.
in the midband(i.e. between low & high frequency) Gain of amp is almost constant. All capacitances are ignored in this region. Gain depends on value of passive element(resistors). So gain is independent of frequency
- #4
ratn_kumbh
- 9
- 0
High pass filters are those circuits which allow higher frequency component of any i/p signal to pass & blocks lower frequency. And just opposite for Low pass filter. See the attachment. in low freq section gain is low and it increases with frequency. Thus allowing higher frequencies in that region to pass. & thus in low freq region it is acting as high pass filter. And same analysis for high frequency part where gain is decreasing with frequency. In attachment Bandwidth of amplifier is that portion which has Constant gain.calmel said:
Attachments
- #5
sakkaf_90
- 8
- 0
thank u
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