A transmitter must operate at a frequency of 168.96 MHz with the deviation of +/- 5kHz. It uses three multipliers – a doubler, a tripler, and a quadrupler. Phase modulation is used. Calculate the frequency of the carrier crystal oscillator and the phase shift required to produce the necessary deviation at a 2.8 kHz modulation frequency.

Carrier Frequency =            Phase Shift =

how to design logic circuit for bcd 7 segment truth table and k-map for 'OFF', 'ATT', 'FIRE'

1.How are the various meters connected in a circuit : series or parrellel.

2. which color probes, when properly inserted, go into which holes of a multimeter in the ohm and voltage measuring mode. And, given a positive voltage measurment, in this properly set meter, which way will the current flow?

3. Determine maximum permitted voltage or current for a rated resistor.

4. slide wire potentiometer : electric field in the wire and how to calculate potential difference alone the wire.

5. what is the output effect of a pn junction diode on an input ac voltage. 6. given an electric potential versus position plot, be able to identify. a.elecric field directions b. equalibrium positions c. electric field stregths: maxima and minima d. potential energy maxima and minima 7. write the nodal current equations and voltage loop equations for a multiple loop circuit.

Describe three types of memory that are used in an MSP430, explain specifically what each memory type’s purpose and why that type of memory is best suited for that use.

What are the advantages of using Laplace transform? Justify your answer

Assume a transmission line with ZL = 65 + j40Ω and Zo = 30Ω. If the frequency of the
line is 2GHz, use the Smith Chart to find: i) the reflection coefficient; ii) the distance to the
first voltage maximum; iii) the voltage standing wave ratio; iv) the admittance of the load;
v) the position of the short-circuited stub on the main line for a perfect impedance matching;
vi) the length of the short-circuited stub. (Show all steps on the Smith chart)

1- Classify the power switches according to the ability to control

2- What are the conditions of turning on the thyristor. State the methods of turning it off. What is the main difference between thyristors and GTO

3- Describe the behavior of TRIAC

4- Derive the expressions of the average load voltage and current in single-phase half-wave controlled rectifiers and resistive load. Draw the waveforms of supply voltage, output voltage, output current, thyristor voltage and thyristor current

5- In a single-phase half-wave controlled rectifier and resistive load, it is desired to get an average load voltage of 80 V. Determine the firing angle if the ac supply voltage is 220 V. If the load resistance is 30 Ω, calculate the average load current and design the thyristor. The volt-drop across the device Von during conduction is 2V. Determine the average conduction losses.

6- In a single-phase half-wave controlled rectifier and R-L load it was found that conduction angle of the thyristor is 160o when the firing angle is 50o. Calculate the average load voltage if the circuit is supplied from a 140 V ac source. Draw the waveforms of supply voltage, output voltage, output current and thyristor voltage.

7- In a single-phase half-wave rectifiers with R-L load and a freewheeling diode FWD, calculate the average load voltage if the firing angle is 30o and the supply voltage is 150 V. Draw the waveforms of supply voltage, output voltage, load current, thyristor current, FWD current and thyristor current.

8- Derive the expressions of the average load voltage and current in single-phase full-wave controlled rectifier with center tapped transformer and resistive load. Draw the waveforms of supply voltage, output voltage, output current, and thyristor current.

9- In a single-phase full-wave controlled rectifier with center tapped transformer and resistive load, it is desired to get an average load voltage of 140 V. Determine the firing angle if the ac supply voltage is 200 V. If the average load power is 700 W, calculate the average load current and design the thyristor. The volt-drop across each thyristor Von during conduction is 1.8V. Determine the average conduction losses of the thyristors.

10- Derive the expressions of the average load voltage and current in single-phase full-wave controlled rectifier (bridge rectifier) and resistive load. Draw the waveforms of supply voltage, output voltage, output current and thyristor current.

11- In a single-phase full-wave controlled rectifier (bridge rectifier) and resistive load, it is desired to get an average load voltage of 50 V. Determine the firing angle if the ac supply voltage is 150 V. If the average load power is 300W, calculate the average load current and. Design the thyristor.

12- Derive the expressions of the average load voltage in single-phase full-wave controlled rectifier (bridge rectifier) and highly inductive load. Draw the waveforms of supply voltage, output voltage, output current and thyristor current.

13- In a single-phase full-wave controlled rectifier (bridge rectifier) and resistive load, it is desired to get an average load voltage of 90 V. Determine the firing angle if the ac supply voltage is 230 V. If the average load power is 270 W, calculate the load current and. Design the thyristor.

14- The single-phase half wave rectifier has a purely resistive load of R and the delay angle is α=π/2, determine: ??? , ??? , ????, ????.
Plot : Is , Vs , VL , VT , Ig

You are given the roots of a polynomial as: x1 = 3

x2 = -1+j5 x3 = -1-j5

• - Find this polynomial. Express it in Matlab.

• - Draw this polynomial’s graph.

Quiz on Reliability, ESD, Ethics Conduct. Select the correct answer for each

a) How is a product expected to fail after a very long time in use?

-Metal electromigration will short out the power supply

-Wearout

-MOS gate oxide will burst

-Electrical overstress

-The "divide" function will start losing bits randomly

b) Is there an issue preventing continuous improvement for better reliability in manufacturing?

-Customers who design high reliability products with your semiconductor parts will not allow substantial changes in manufacturing once the process is released

-No, customers demand continuous process improvement and lower price regardless of what needs to be changed

-Once the process achieves Six Sigma qualification on 3 parameters, no further change is permitted

-Customers expect the manufacturer to buy newer equipment every year to improve product reliability

-Manufacturers can always change the specification limits, but are not permitted to reduce variation

c) Explain HBM ESD?

-System power is cycled off to drain the charge, then the human accumulates an equivalent charge

-A cable connects from a human to the test board, causing a visible arc

-The semiconductor part is charged, and then zaps itself when metal contact is made

-Charged person grounds herself through a wriststrap, causing a fast discharge

-Charged person makes electrical contact with metal of a semiconductor part, causing a fast discharge

d) Why is prevention of CDM a high priority among manufacturers?

-VDM discharges can be so fast that even a small amount of stored charge can cause damage, and discharge may happen multiple times

-The slow discharge tends to drain batteries without you knowing it

-CDM occurs at so much higher voltage than HBM that it's much more dangerous

-Rules for prevention of CDM are more difficult and cost much more money to implement

-It's embarrassing when your customers find out that you have the same problem as them

Design up counter asyncronous MOD 12 and MOD 14 with JK Flip-Flop

Re-submission of question.                          Consider the full-bridge single-phase inverter with input voltage equal to 200V. This inverter is controlled by sinusoidal PWM technique with amplitude modu-      lation index equal to 0.5 to generate a 3- level half-wave symmetry waveform with frequency equal to 50 Hz.                            e)Calculate the amplitude of fundamen-   tal frequency.                                                  f) Draw the waveforms of refrence and      carrier signals.                                                g) Obtain the waveform of output voltage.                                                          h)Design the trigger signals of switches.   Thanks for your help.

Electromagnetic Waves question :
Drive the field expressions for TE modes in parallel plate wave guide

Question 2

(a) Explain the meaning of the following terms in the context of cellular telephony networks:

(i) Frequency reuse

(ii) Trunking

(iii) Micro and macro cells

(iv) Umbrella cells Describe the trade-off that must be made when selecting the number of cells which should be clustered together to form a location area in a cellular network. [6 marks]

(b) A number of techniques are used on both the base station and mobile station (i) to manage power consumption, and (ii) to minimise the effects of network interference. For each of the following terms, describe how the feature works and comment on whether, and how, it is used to address (i) and\or (ii).

(i) Time Division Duplexing

(ii) Adaptive Power Control

(iii) Discontinuous Transmission [4.5 marks]

(c) Subscriber A is a subscriber of an Irish mobile network who is roaming on a French mobile network. Subscriber B is a subscriber of UK mobile network who is currently an inbound roamer on subscriber A’s home network. Subscriber A initiates a voice call to subscriber B.

(i) Describe, with the aid of a diagram, the steps involved in the routing of this call to the point where subscriber B’s handset is paged.

(ii) Using this example, clearly explain the difference between late and early call forwarding.

(iii) Explain the meaning of the term call tromboning in the context of one of these call forwarding scenarios and outline how this is typically resolved when it occurs. [9.5 marks]