Calculate the maximum value of Rn if the resolution of the

Part -1:

Question 1. FIGURE 1 shows the block diagram of a superhetrodyne radio receiver. In a test a 20∝V signal was fed from the aerial into the first stage of the receiver, a radio frequency amplifier. This signal is the passed through several stages of the receiver to eventually appear at the input to the AM detector. For the AM detector to work satisfactory it requires a minimum signal level of -3dB(mW). Calculate the required minimum gain of the fifth intermediate amplifier given the data in TABLE 1.

Stage

Gain

RF amplifier

+10 dB

Mixer

-7 dB

BPF

-1 dB

IF1

+15 dB

IF2

+15 dB

IF3

+20 dB

IF4

+10 dB

TABLE 1

2446_figure.jpg

FIG. 1

Question 2. As a rule of thumb, the perceived noise from a source falls by 6 dBA with every doubling of the distance from the source.

If a 1 MW wind turbine (FIGURE 2) produces 103 dBA of noise within one metre of its base, estimate the distance from the turbine at which the noise can be reckoned to have fallen below the background noise level of 40 dBA.

1773_figure1.jpg

FIG. 2

Question 3. A simplified model of ADC noise refers the noise to a noisy input source resistance Rn while assuming the rest of the signal path to be noiseless. FIGURE 3 represents a particular 18-bit ADC that has a 10 V input voltage range. The ADC has a bandwidth of 1 MHz.

Calculate the maximum value of Rn if the resolution of the ADC is not to be adversely affected by thermal noise. Assume the ADC operates at 25°C.

[N.b. The voltage resolution of an ADC is equal to its overall voltage measurement range divided by the number of discrete values possible on its output.]

1271_figure2.jpg

FIG 3.

Question 4. The specification for a 4-way TV antenna amplifier [FIGURE 4] is given in TABLE 2, below.

Bandwidth

40-862 MHz

Gain

20 dB

Noise Figure

6 dB

Max. Output

85 dBµV

Input Impedance

75 ?

Output Impedance

75 ?

TABLE 2

2499_figure3.jpg

FIG. 4

(a) Determine the voltage required on the input of the amplifier to give the maximum output of 85 dB∝V.

(b) If the signal level from the aerial is 5 dBmV and the input noise level is 20 dB∝V, calculate the signal-to-noise ratio on the output of the amplifier.

Question 5. A voltage amplifier ideally should have the input-output relationship of vo = 100vi but in practice the relationship is vo = vi(98 + 2vi).

Calculate the %age second harmonic distortion present in the amplifier's output for a sinusoidal input of 10 mV r.m.s.

Question 6.

You may find the following relationship helpful in answering this question:

For a lossless line:

The characteristic impedance is given by Zo = √L/C and the velocity of propagation by vp = 1/√LC

where L and C are, respectively, the line's inductance and capacitance per metre length.

A transmission line is formed by two identical parallel tracks in a printed circuit board, as depicted in FIGURE 5. The line has a length of 50 mm and all line terminations are of 70 ?. The line can be assumed to be lossless.

(a) Use equations (4) and (5) from the lesson to calculate the magnitude of the NEXT and FEXT voltages generated in the victim conductor when the source voltage, Vin, in the aggressor conductor is a voltage step of 2 V with a rise time of 100 ps.

[Note that the Vs voltage at the input to the aggressor conductor is

Vs = Vin. Rin/(Rin + Z)

(b) Sketch the NEXT and FEXT waveforms.

The relevant parameters for the line are listed in TABLE 3.

202_figure4.jpg

FIG. 5

Parameter

Value

Line inductance

400 nH per m

Line capacitance

80 pF per m

Mutual inductance

80 nH per m

Mutual capacitance

10 pF per m

TABLE 3

Part -2:

Question 1. Determine the voltage VO in the circuit of FIGURE 1 for:

(a) β = 50, VBE = 0.7 V Vs

(b) β = 250, VBE = 0.7 V.

Comment on the significance of your result.

VS 12 V
RC 1 k?
RE 200 ?
RB1 15 k?
RB2 3.3 k?

340_figure.jpg

FIG. 1

Question 2. State the effects of negative feedback, when applied in a voltage amplifier, upon:

- the overall amplification

- variations in transistor gain

- non-linearity

- output impedance.

Question 3. Estimate the power developed in the 8 ? speaker of the circuit of FIGURE 2 for a 1 kHz sinusoidal input signal of 100 mV peak. All capacitors may be assumed to act as a short circuit at the frequency of operation.

Compare your estimate with that derived from a PSpice simulation.

[A Simetrix version of the circuit can be downloaded from the module's Learning Materials on BlackBoard.]

1253_figure1.jpg

FIG. 2

Question 4. FIGURE 3 shows the circuit of a multistage amplifier. Identify the stages and describe the operation and principle features of the amplifier. You should also make an estimate of the maximum output current of the amplifier.

767_figure2.jpg

FIG. 3

Question 5. FIGURE 4 shows an amplifier circuit. operation and performance of the circuit. should:

Write a short report on the In completing the report you

- Explain the operation of the circuit and in particular the role of resistors R1 and R2.

- Build the circuit in PSpice and use it to determine:

(i) the quiescent value of Vout.

(ii) the voltage gain for a 100 mV, 1 kHz , input signal.

- Sketch the small-signal equivalent circuit of the amplifier and use it to estimate the voltage gain. Compare your answer with that of (ii) above.

- Attempt to calculate the quiescent value of Vout. Compare your answer with that given by the PSpice model. Try to explain any discrepancies.

[Hint : Apply the appropriate equation (1 or 2) of Lesson 4.]

2368_figure3.jpg

FIG. 4


Order Assignment gulfassignmenthelp Rated 4.9 / 5 based on 22789 reviews.
  • Rihab Khan

    Hey, My name is Rihab and I am a student at the University of Sharjah and require your urgent assistance to write assignments on Industrial Automation and Renewable Energy. I would be writing these by myself, but I am busy in attending a seminar and working on one more project at the same time. So now you might have understood that I have no time and I don’t want to lose an opportunity to get good grades. So after looking over the web, I found your name, multiple times and after researching a little I found out that you provide Gulf assignment help at very reasonable prices and the most important thing I like is the quality of content you provide. The assignment checking standards are very strict in my university, so I just wanted to know that could your expert tutors will be able to create the assignment exactly according to my instructions. One more thing that I would like to mention is that I need both the assignments on Industrial Automation and Renewable Energy within a week because next Saturday I have to submit them. So can you please respond to my comment quickly and please be sure that I would like to get the best grades on the basis of assignments written by you. Kindly reply fast.

  • Dahlia

    Hello Sir/Mam ..My name is Dahlia and I am currently pursuing BSc in Electrical Engineering from UAE and I am very concerned about my next assignment on Electric Circuits and another one on Digital and Embedded Systems. I am not that aware of the specifics of these subjects because last month I met with an accident and was not able to attend a few classes. But now I have to submit assignments on the same subjects and I don’t have time to read or prepare them myself. The teachers will not be lenient in grading my assignments and I also don’t want to get poor grades because it will affect my final result. So I have come to in hopes that you could provide me with the best assignment help services in the Gulf region. So could you please tell me if you can write an assignment on Electric Circuits and another one on Digital and Embedded Systems and please maintain the quality of content. Thanks.

Captcha

Seeking Trusted Advice of High Skilled Tutors for Gulf Assignments? Order Now