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Subelement F

Receivers

Section 46

Filters and IF Amplifiers

What is the primary purpose of the final IF amplifier stage in a receiver?

  • Dynamic response.
  • Correct Answer
    Gain.
  • Noise figure performance.
  • Bypass undesired signals.

What is the primary purpose of the final IF amplifier stage in a receiver?

Gain.

The key word here is FINAL, so in the final stage the IF amplifier simply amplifies, GAIN.

In the initial stage, you can use the IF amplifier to adjust frequency selectivity when the desired frequency is difficult for tuning.

This is partly done through the ability to reject radio frequencies that are undesired.

The IF amplifier works from the ranges of 0.1 Hz to 1 kHz, and also from 10 MHz to 300 GHz.

See Wikipedia's article on Intermediate-frequency amplifier

Also, see the Analog site for the article on Tuned IF Amplifier Applications

And, see the Electronics Notes site for the article Superheterodyne Radio IF Amplifier & Filter

Please see the Encyclopedia2 thefreedictionary site for the article on intermediate-frequency amplifier

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What factors should be considered when selecting an intermediate frequency?

  • Cross-modulation distortion and interference.
  • Interference to other services.
  • Correct Answer
    Image rejection and selectivity.
  • Noise figure and distortion.

What factors should be considered when selecting an intermediate frequency?

Image rejection and selectivity.

You can use IF amplifier to adjust frequency selectivity when the desired frequency is difficult for tuning.

This is partly done through the ability to reject radio frequencies that are undesired.

The IF amplifier works from the ranges of 0.1 Hz to 1 kHz, and also from 10 MHz to 300 GHz.

See Wikipedia's article on Intermediate-frequency amplifier

Also, see the Analog site for the article on Tuned IF Amplifier Applications

And, see the Electronics Notes site for the article Superheterodyne Radio IF Amplifier & Filter

Please see the Encyclopedia2 thefreedictionary site for the article on intermediate-frequency amplifier

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What is the primary purpose of the first IF amplifier stage in a receiver?

  • Noise figure performance.
  • Tune out cross-modulation distortion.
  • Dynamic response.
  • Correct Answer
    Selectivity.

What is the primary purpose of the first IF amplifier stage in a receiver?

Selectivity.

You can use IF amplifier to adjust frequency selectivity when the desired frequency is difficult for tuning.

This is partly done through the ability to reject radio frequencies that are undesired.

The IF amplifier works from the ranges of 0.1 Hz to 1 kHz, and also from 10 MHz to 300 GHz.

See Wikipedia's article on Intermediate-frequency amplifier

Also, see the Analog site for the article on Tuned IF Amplifier Applications

And, see the Electronics Notes site for the article Superheterodyne Radio IF Amplifier & Filter

Please see the Encyclopedia2 thefreedictionary site for the article on intermediate-frequency amplifier

Last edited by markadlerdallas. Register to edit

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What parameter must be selected when designing an audio filter using an op-amp?

  • Correct Answer
    Bandpass characteristics.
  • Desired current gain.
  • Temperature coefficient.
  • Output-offset overshoot.

What parameter must be selected when designing an audio filter using an op-amp?

Bandpass characteristics.

See the Electronics Tutorial site for the article Active Band Pass Filter and the article Passive Band Pass Filter

Also, see the Analog IC Tips site for the article An overview of filters and their parameters, Part 3: Key parameters

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What are the distinguishing features of a Chebyshev filter?

  • It has a maximally flat response over its passband.
  • It only requires inductors.
  • Correct Answer
    It allows ripple in the passband.
  • A filter whose product of the series- and shunt-element impedances is a constant for all frequencies.

What are the distinguishing features of a Chebyshev filter?

It allows ripples in the passband.

These filters increase selectivity when distinguishing among frequencies.

See Wikipedia's article Chebyshev filter

Also, see the Electronics Notes site for the article What is a Chebyshev RF Filter - the basics

And, see El Pro Cus site for the article Different Types of Chebyshev Filters with Calculations

Please see the Science Direct site for the article Chebyshev Filter

View the pdf document from the Analog site article Chebyshev Filter

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When would it be more desirable to use an m-derived filter over a constant-k filter?

  • When the response must be maximally flat at one frequency.
  • When the number of components must be minimized.
  • When high power levels must be filtered.
  • Correct Answer
    When you need more attenuation at a certain frequency that is too close to the cut-off frequency for a constant-k filter.

When would it be more desirable to use an m-derived filter over a constant-k filter?

(D).   When you need more attenuation at a certain frequency that is too close to the cut-off frequency for a constant-k filter.

There are the m- and k-constant filters. The k one produces a sharp drop (cut-off) edge.

The m-derived filter matches the impedance. Since the attenuation increases rather quickly at the cutoff frequency, the filter's output stays the same in the pass band.

See Wikipedia's article on m-derived filter, and the article on Constant k filter

Also, see the Electronics Tutorials site for the article on m Derived Filter and the article on Constant K Filter

And, see the EEEGuide site for the article on m Derived Filters

Please see the Electronics Notes site for the article What is a Constant-K Filter: the basics

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