hi,
I've been asked to design a project for the university, unfortunately I'm running out of time.
the project is:

Design a two-stage amplifier using either bipolar or FET transistors or a combination of both. You will have to select suitable transistors capable of, providing a voltage or a power gain of at least 100dB and covering frequencies from 100Hz to 1MHz. you are also required to simulate the amplifier operation and it's frequency response including the 3-dB bandwidth. Explain each step in the design and with your results and plots.

Note: You are free in your selection of the transistors and the bias rails and may add a buffer stage if required. Also, you must site all references used in the design process.


I'm running out of time and i need any possible help from you guys, please if you can provide me with any useful information.

thanks in advance

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This would have been better posted in the homework forum. You'll find folk reluctant to help if you don't show some attempt at a solution. "Running out of time" doesn't quite cut it as a justification for seeking help.

 

Hi,
You may use a VCO circuit, taking under consideration the value of the capacitor, using BJT, with voltage ranging from 2.5-5 volts, that enables you to generate 100Hz to 1MHz. The ciruit act as on-off switch that will generate a triangler wave, with required frequncy and dBs. The are many ways to solve this project, another one is using 2 stage OP-AMPs

 

http://www.qsl.net/wa1ion/

See if something there will get you started.

 

Hi,
You may use a VCO circuit, taking under consideration the value of the capacitor, using BJT, with voltage ranging from 2.5-5 volts, that enables you to generate 100Hz to 1MHz. The ciruit act as on-off switch that will generate a triangler wave, with required frequncy and dBs. The are many ways to solve this project, another one is using 2 stage OP-AMPs

Hi samsmath,

I think you might have misunderstood the question.

The goal is to design a two-stage amplifier which will amplify signals in the 100Hz to 1MHz range. You appear to be suggesting a variable frequency oscillator design.

 

yes, but who said that vco can't be used for amplification? google it and you'll see what am talking about? rethink about it my friend. All the best

 

Please see attached file, which shows the schematic of bjt and fet wideband, preamplified. Hope this help.

 

yes, but who said that vco can't be used for amplification? google it and you'll see what am talking about? rethink about it my friend. All the best

I more than happy to be corrected. Perhaps you could produce the proof by way of an example. I've never seen a VCO used as an amplifier - let's say in an audio amplifier or an RF amplifier. It would make interesting reading.

Perhaps you are referring to PWM type switch-mode amplifiers or chopper type amplifiers...??

That's probably beyond the scope of what the OP was looking for in this case.

Actually it would be interesting to know if a class "D" amplifier is capable of 1MHZ bandwidth - anyone know what's currently achievable?

 

hi,

have a look at this white paper and you'll see what i mean

http://www.csio.res.in:8085/ncci/IC...dulator using the PLL demodulation method.pdf

although i admit i rushed in answering not reading the whole quote, because the problem limits the design to bjt and fet not a whole proper system like the one in the document above.

 

HEY! YOU THERE! THE ONE USING MY INITIALS!



And even weirder, I use a Blackberry also.

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