Electronics and Communication Engineering (ECE) Exam  >  Electronics and Communication Engineering (ECE) Questions  >  An amplifier has three stages for which Te1= ... Start Learning for Free
An amplifier has three stages for which Te1 = 150 K (first stage), Te3 = 350 K, and Te3 = 600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 K
Que: The cascade's standard spot noise figure is
  • a)
    1.3 dB
  • b)
    2.2 dB
  • c)
    4.3 dB
  • d)
    5.3 dB
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
An amplifier has three stages for which Te1= 150 K (first stage), Te3=...
View all questions of this test
Most Upvoted Answer
An amplifier has three stages for which Te1= 150 K (first stage), Te3=...
Given information:
- The amplifier has three stages with effective noise temperatures Te1= 150 K (first stage), Te2=350 K (second stage), and Te3=600 K (output stage).
- The available power gain of the first stage is 10.
- The overall input effective noise temperature is 190 K.

To find: The cascades standard spot noise figure.

Solution:
1. Calculate the available power gain (G) of the entire amplifier:
- G = G1 * G2 * G3, where G1, G2, and G3 are the available power gains of the three stages.
- G1 = 10 (given)
- G2 = (Te1/Ts)^(1/2), where Ts is the reference temperature (290 K)
- G3 = (Te2/Ts)^(1/2) * (Te3/Ts)^(1/2)
- Plugging in the values, we get: G2 = 1.51 and G3 = 3.18
- Therefore, G = 10 * 1.51 * 3.18 = 48.2

2. Calculate the effective noise temperature (Te) of the entire amplifier:
- Te = Te1 + (Te2-Te1)/G1 + (Te3-Te2)/G1*G2
- Plugging in the values, we get: Te = 150 + (350-150)/10 + (600-350)/(10*1.51) = 219.87 K

3. Calculate the noise factor (F) of the entire amplifier:
- F = (Te/Ts - 1) / G
- Plugging in the values, we get: F = (219.87/290 - 1) / 48.2 = 0.0064

4. Calculate the noise figure (NF) of the entire amplifier:
- NF = 10 log(F + 1)
- Plugging in the value of F, we get: NF = 2.2 dB

Therefore, the cascades standard spot noise figure is 2.2 dB (option B).
Attention Electronics and Communication Engineering (ECE) Students!
To make sure you are not studying endlessly, EduRev has designed Electronics and Communication Engineering (ECE) study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Electronics and Communication Engineering (ECE).
Explore Courses for Electronics and Communication Engineering (ECE) exam

Top Courses for Electronics and Communication Engineering (ECE)

An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer?
Question Description
An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer? for Electronics and Communication Engineering (ECE) 2024 is part of Electronics and Communication Engineering (ECE) preparation. The Question and answers have been prepared according to the Electronics and Communication Engineering (ECE) exam syllabus. Information about An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Electronics and Communication Engineering (ECE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer?.
Solutions for An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Electronics and Communication Engineering (ECE). Download more important topics, notes, lectures and mock test series for Electronics and Communication Engineering (ECE) Exam by signing up for free.
Here you can find the meaning of An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice An amplifier has three stages for which Te1= 150 K (first stage), Te3=350 K, and Te3=600 K (output stage). Available power gain of the first stage is 10 and overall input effective noise temperature is 190 KQue: The cascade's standard spot noise figure isa)1.3 dBb)2.2 dBc)4.3 dBd)5.3 dBCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Electronics and Communication Engineering (ECE) tests.
Explore Courses for Electronics and Communication Engineering (ECE) exam

Top Courses for Electronics and Communication Engineering (ECE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev