Transcript Multi-functional Packaged Antennas for Next

ELCT 371: Electronics
Pre-Req: CSCE 211, ELCT 222
Instructor: Dr. Goutam Koley
Office: SWGN 3A12, 777- 3469, [email protected]
Lecture Hours: Tue & Thurs 12.30 – 1:45 AM
SWGN 2A19
Office Hours: Mon 2.30 – 3.30 pm, and by appointment
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Objective
Objective: To learn the basics of analog circuit design
and analysis
Text book: Electronics, by Allan R. Hambley, 2nd Edition, Prentice
Hall, Upper Saddle River, NJ 07458, 2000
ISBN # 0136919820
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Schedule and Grading
Class: Aug 19 – Dec 3; 28 lecture days.
Final Exam: Dec 10, 2010 at 2.00 pm.
Detailed schedule posted on the website
Grading:
Homeworks (6):
Quizzes (Best 4 of 5 total):
Midterms (2):
Final:
Grades (Total 100 points):
A: 90 - 100
B+ : 85 – 90
C: 70 – 74
D+: 65 – 69
B: 80 – 84
D: 60 – 64
15 %
15 %
35 %
35 %
C+ : 75 - 79
F: <60
Curve: All grades will be normalized. The highest overall individual score (out of
100) will be made 100, and all the others will be multiplied by the ratio before
assigning the final grade. If there are confusions regarding any grading please bring
it to my attention immediately after the grading is done.
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Some reminders…
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Eating or drinking in class is NOT preferable. However, if
you absolutely have to, you must not disturb others.
Do not enter the class if you are more than 15 minutes
late, without very valid reasons
No retake of exams/tests permitted unless you let me know
prior to the test/exam, and have valid reasons
PLEASE ADHERE TO THE UNIVERSITY OF SOUTH
CAROLINA HONOR CODE (No cheating in any form!!!)
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1.4 Basic Amplifier Concepts
An ideal amplifier produces an output signal with a larger amplitude
while maintaining the same waveshape
Amplifier Black Box concept
Microphone Amplifier
1 mV
Av=10,000
Loudspeaker
10 V output
v0 (t )  Avvi (t )(1.2)
vi  input voltage
v0  output voltage
Av  voltage gain
Fig. 1.15
Q: Is a transformer an amplifier?
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1.4 Basic Amplifier Concepts
Inverting and Noninverting Amplifiers:
Inverting Amplifier
Noninverting Amplifier
Av 
is a negative number
Av 
is a positive number
v0 (t )  Avvi (t )(1.2)
Fig. 1.16
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1.4 Basic Amplifier Concepts
The Voltage-Amplifier Model: Basic concepts
Input impedance Zi for a typical
oscilloscope is a 1 MW resistance in
parallel with 47 pF capacitance
Fig. 1.17
vs is the source voltage
Rs is the source resistance
RL is the load resistance
3 parameters that completely defines
an amplifier black box
Avo is the open circuit voltage gain
Ri is the input resistance of the amplifier
Ro is the output resistance of the amplifier
Ri is the equivalent resistance looking into the input terminals of the amplifier and
Ro is the same looking into the output terminals
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1.4 Basic Amplifier Concepts
The Voltage-Amplifier Model: Real amplifiers and voltage gain
•
•
•
Real amplifiers cannot deliver a fixed voltage to an arbitrary load resistance
Output voltage changes with load resistance - Higher for larger RL and lower
for smaller RL
The amplifier output resistance accounts for the reduction in output voltage
Fig. 1.17
Avo is the open circuit voltage gain of the amplifier, meaning the load is infinite.
Thus there is no drop across the resistances, and v0 = Avovi
• Actual amplifier voltage gain Av=v0/vi is always smaller than Avo
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1.4 Basic Amplifier Concepts
Current Gain
i0
Ai 
ii
i0 v0 / RL
Ri
Ai  
 Av
ii vi / Ri
RL
v0
Av 
vi
is the voltage gain with the load resistor
connected. Note that Av is smaller than Av0
Fig. 1.17
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1.4 Basic Amplifier Concepts
Power Gain
•
Assuming the input impedance and load impedance are purely resistive, the
average power is the product of the rms current and rms voltage.
Fig. 1.17
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1.4 Basic Amplifier Concepts
Example 1.1: Find voltage gain, current gain, and power gain for the
circuit below
Fig. 1.18
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1.5 Cascaded Amplifiers
Fig. 1.19
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1.5 Cascaded Amplifiers
Example 1.2 Analysis of a Cascaded Amplifier
Fig. 1.20
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