Lecture #6 - Dynamic Range and Sensitivity Flashcards

1
Q

What is dynamic range?

A

The difference between smallest and largest input or output signal power for which a component or system has desirable characteristics.

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2
Q

How can the dynamic range of the component be specified?

A
  1. Linear dynamic range
  2. Spurious free dynamic range
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3
Q

Explain what LDR is

A

LDR is the difference between the largest and smallest signal output power, while the component is being driven in the linear operating range.

  1. Largest signal o/p power is limited by the 1dB compression point
  2. Smallest signal o/p limited by noise floor
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4
Q
A
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5
Q

What are meant by suprious tones?

A
  • Nonlinearity of active RF components results in harmonics and intermodulation products.
  • Narrowband devies and bandpass filters with high stop band attenuation -> harmonics can be filtered.
  • IM3 products located in desired passband and cannot be removed. –> spurious tones
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6
Q

What is the lower limit of SFDR defined by

A

The o/p power of the fundamental signal is equal to the noise floor.

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7
Q

What is the upper limit of SFDR defined by

A

The largest signal power is limited by the o/p power level of an IM3 product.

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8
Q

What does it mean that the SFDR is smaller than the LDR

A

Indicates that the presence of IM products can distort the fundamental o/p signal much before the device under test goes into compression (experiences non-linearity).

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9
Q

Why do we want an o/p signal power to exceed the noise floor by a certain amount

A

When the signal just barely hits the noise (o/p power signal = noise floor); it means that SNR is 0dB.

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10
Q

What is a minimum detectable signal?

A

The output signal power should exceed the noise floor by a certain amount. (SNR > 0dB)

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11
Q

What is sensitivity?

A

The minimum input signal power that a receiver can detect for a given output SNR is called sensitivity.

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12
Q

What happens if the input power has to be higher to be detected means for the reciever?

A

It has a lower sensitivity.

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13
Q

Why use noise temperature and why does NF always assume?

A

A temperature of 290 degree kelvin

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