Mw&Oc Labmannual

7/30/2019 Mw&Oc Labmannual

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Microwave & Optical Communication Lab Manual

BUCHEPALLI VENKAYAMMA

SUBBAREDDY ENGINEERING COLLEGE (Approved by AICTE & Affiliated to JNTU, Kakinada)

Kurnool Road, CHIMAKURTHY 523 226, Prakasam DT., A.P.

MICROWAVE & OPTICAL COMMUNICATION LAB

MANUAL

IV ECE (I-SEM)

Department of ECE BVSREC


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INDEX

S.NO NAME OF THE EXPERIMENT

PAGES

REMARKS

FROM TO

Part A ( Any seven Experiments)

1 Reflex Klystron characteristics.

2 Gun Diode characteristics

3 Measurement of frequency & Wavelength

4 Directional Coupler Characteristics.

5 Attenuation measurement.

6 Impedance and frequency measurement.

7 Waveguide parameters measurement.

8 Scattering parameters of circulator.

9 Scattering parameters of Magic Tee.

Part B ( Any Five Experiments)

10Characterization of LED.

11Characterization of Laser Diode.

12Intensity modulation of Laser outputthrough an optical fiber.

13Design of fiber optic digital link fortransmission of digital signals.

14Measurement of Numerical Aperture.

15Measurement of Losses for analog opticallink.



3/31


Exp.No: Date:

REFLEX KLYSTRON CHARACTERISTICS

AIM: To Study the characteristics of the Reflex Klystron tube and to determine its electronic

tuning range.

APPARATUS REQUIRED:

1. Klystron tube

2. Klystron power supply

3. Isolator

4. Frequency meter

5. Variable attenuator6. Detector mount

7. C.R.O

EXPERIMENTAL SETUP:


Isolator

Variableattenuator

FrequencyMeter

DetectorMount

Klystron

PowerSupply

KlystronMount CRO

Slotted linesection


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PROCEDURE:

Mode studies:

1. Connect the components and equipment as shown in experimental setup.

2. Keep the control knob of Klystron power supply as below:

Mode switch: CW

Beam voltage knob: Fully anti-clockwise

Repeller voltage knob: Fully clockwise

Meter switch: Cathode voltage position

3. Rotate the frequency meter at one side.

4. Switch on the klystron power supply, CRO and cooling fan for the Klystron tube. Wait for 1-2

minutes for the klystron to respond.

5. Cathode voltage knob at minimum position gives a beam voltage of 235 V. Observe beam current

on the meter by changing meter switch to beam current position. "The beam current should not be

more than 30mA"

6. Now change the meter switch to repeller voltage position.

7. Select proper range for the power meter so that power output of maximum mode will not exceed

the meter range.

8. Decreasing the reflector voltage, record output Voltage.

10. Plot Output Voltage versus repeller voltage to get mode curves.



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MODEL GRAPH:

OBSERVATIONS:

Result:


S. No. Repeller voltage(Volts ) Voltage output (mV)


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Exp.No: Date:

GUNN DIODE CHARACTERISTICS

AIM: To study the V-I Characteristics of Gunn diode

APPARATUS REQUIRED:

1. Gunn power supply

2. Gunn oscillator

3. PIN modulator

4. Isolator

5. Frequency Meter

6. Variable Attenuator

7. Detector mount

8. Slotted Section

9. CRO.

EXPERIMENTAL SETUP :



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PROCEDURE:

. Set the components as shown in fig.

. Initially set the variable attenuator for maximum attenuation.

. Keep the control knobs of Gunn Power Supply as below:

Gunn Bias Knob - Fully anticlockwise

PIN bias knob - Fully anticlockwise

PIN mode frequency - Any position

Mode switch - CW Mode

. Set the micrometer of Gunn Oscillator at 7 mm for required frequency of operation.

. Switch ON the Gunn Power Supply and cooling fan.

6. Measure the Gunn diode current corresponding to the various voltage controlled by

Gunn Bias knob through the panel do not exceed the bias voltage above 10.5V

7. Plot the voltage & current reading on the graph.

8. Measure the threshold voltage which corresponds to maximum current.

OBSERVATION:

S.no Gunn Bias Voltage (V) Gunn Diode Current (I)

MODEL GRAPH:

Current voltage characteristics of Gunn oscillator:



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RESULT:

Exp.No: Date:

MEASUREMENT OF FREQUENCY & WAVELENGTH

AIM: To determine the frequency and wavelength of a microwave signal.

APPARATUS REQUIRED:

1. Klystron Power supply,

2. Isolator.

3. Klystron mount

4. Frequency meter.5. Variable Attenuator.

6. Slotted line section.

7. Tunable probe.

8. Matched load.

9. CRO/VSWR

EXPERIMENTAL SETUP:

PROCEDURE:


Isolator

Variableattenuator

FrequencyMeter

Matchedload

KlystronPowerSupply

KlystronMount

Slotted linesection

Tunableprobe

CRO


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1. Set the components & equipment as shown in the fig.

2. Set the variable attenuator at no attenuation position.

3. First connect the matched termination after slotted section.

4. Keep the control knobs of klystron power supply as below:Meter switch - off

Mod switch - AM

Beam voltage knob - Fully anti-clock wise

Reflector voltage knob Fully clock wise

AM Frequency and amplitude knob Mid position

5. Switch ON the Klystron power supply, CRO and cooling fan.

6. Tune the meter switch of power supply to beam voltage position and set beam voltage at

230v with help of beam voltage knob, current a round 15 to 20mA.

7. Tune the frequency meter to get a dip minimum voltage on CRO and note down the

frequency directly from frequency meter.

8. Move the tunable probe along with the slotted line to get the max. display of waveform in

CRO. Move the tunable probe to a min Gain position and record the probe position i.e. d1.

9. Move the probe to next min position and record the probe position again i.e d2.

10. Calculate the guide wave length as twice the distance between two successive min.

position obtained as above.

g =2(d1-d2)11. Measure the wave guide inner broad dimension a which will be around 22.86mm

for X- band.

c=2a

12. Calculate the frequency by following equation

__________



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F=c/D = c ( 1/ g2 +1/ c2)

13. Verify the frequency obtained by the frequency meter.

PRECAUTIONS:

1. Loose connection are avoided

2. Note down the readings without any parlance errors.

RESULT:

Exp.No: Date:



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DIRECTIONAL COUPLER CHARACTERISTICS

AIM: To measure Coupling, Directivity, Insertion loss and Isolation of a directional coupler.

APPARATUS REQUIRED:

1. Klystron Power supply,

2. Reflex klystron.

3. Isolator.

4. Frequency meter.

5. Variable Attenuator.

6. Directional Coupler.

7. Matched load.

8. Detector Mount.

9. CRO/VSWR Meter

10. Wave guide stands

EXPERIMENTAL SETUP-1:

EXPERIMENTAL SETUP-2:


Isolator

Variableattenuator

FrequencyMeter

DetectorMount

KlystronPowerSupply

KlystronMount CRO

Slotted linesection


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PROCEDURE:

1. Set up equipment as shown in fig. Without the directional coupler i.e., directly connect

crystal detector with CRO in order to measure Input after attenuator.

2. Set the variable attenuator at maximum position.

3. Keep the control knobs of klystron power supply as below:

Meter switch --- OFF

Mod switch --- AM

Beam voltage knob --- fully anticlockwise.

Reflector voltage --- fully clockwise.

AM Amplitude knob --- around fully clockwise.

AM Frequency knob --- around mid position.

4. ON the klystron power supply, CRO and cooling fan .

5. Connect the detector mount to the slotted line and tuning for the maximum o/p.

6. Note down the output voltage from CRO and consider it as V1.

7. Insert the directional coupler connect it as shown in the experimental set up 2

8. Record the output voltages at port2 and port 3

9. using the outputs calculate insertion loss, isolation loss and coupling factor.


Isolator

Variableattenuator

FrequencyMeter

Directionalcoupler

KlystronPower

Supply

KlystronMount

Matchedload

Slottedline

section

DetectorMount

CRO


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DIRECTIONAL COUPLER

PRECAUTIONS:

1. Loose connection are avoided

2. Note down the readings without any paralleled errors.

3. Beam current should not exceed 20mA

RESULT



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Exp.No: Date:ATTENUATION MEASUREMENT

AIM: To study the substitution method for measurement of attenuation and Hence to determine the

attenuation due to a component under test.

APPARATUS REQUIRED:

1. Klystron power supply.

2. Klystron Mount.

3. Isolator.

4. Frequency Meter.5. Variable attenuator.

6. Detector mount.

7. Test attenuator.

8. CRO.

9. Cooling Fan

10. Waveguide stands

EXPERIMENTAL SETUP:



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PROCEDURE:

1. Set the components and equipments as shown in figure above.

2. Initially set the variable attenuator for maximum attenuation.

3. Terminate the receiving end with unknown load.

4. Keep the control knob of Klystron power supply as follows,Beam voltage : Off

Mod-switch : Am

Beam voltage knob : Full anti clockwise

Reflector voltage knob : Full clockwise

Am-amplitude knob : Full clockwise

Am frequency & amplitude knob : Mid position

5. Switch On the klystron power supply, VSWR meter & cooling fan.

6. Switch On the beam voltage switch and set beam voltage at 300 v

7. Rotate the reflector voltage knob to get deflection in VSWR meter

8. Slowly decrease the micrometer reading and note down the Attenuation from the VSWR meter.

9. Plot a Graph between Attenuation and Micrometer reading.

PROCEDURE FOR FIXED ATTENUATOR:

1. Repeat up to step 4 and insert CRO in place of VSWR meter

2. Tune the bench for maximum output and note down the output voltage as V1.

3. Now insert the fixed attenuator in between slotted section and detector mount and note down

the output voltage as V2

4. Using V1 and V2 calculate the attenuation.

Model graph:



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OBSERVATIONS:

Sr. No. Screw Gauge Reading (mm) Attenuation in Decibel

Precautions:

1. Loose connections are avoided

2. Note down the readings without any error

3. Beam current should not exceed 20mA

Result:



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Exp.No: Date:

SCATTERING PARAMETERS OF CIRCULATOR

AIM: To study operation of circulator and hence measure insertion loss and isolation of a circulator.

APPARATUS REQUIRED:

1. Klystron Power Supply,

2. Klystron Mount,

3. Variable attenuator,

4. Matched termination,5. Crystal detector,

6. VSWR meter,

7. Isolator,

8. Circulator.

EXPERIMENTAL SETUP:

THREE PORT CIRCULATOR:


Isolator

Variableattenuator

FrequencyMeter

DetectorMount

KlystronPowerSupply

KlystronMount CRO

Slotted linesection


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Insertion loss: The ratio of power supplied by a source to the input arm, to the power detected by a

detector in the coupled arm with all other ports matched terminated.

Isolation: Ratio of power fed in Arm 1 by a matched generator to the power detected in port 3 by a

detector with ports 2 terminated in matched loads.

PROCEDURE:

1. Set up the equipment as shown in figure without the ferrite device i.e., directly connect detector

with CRO in order to measure input.


3. Keep the control knob of Klystron power supply as below:

Mode Switch : AM

Beam Voltage Knob : Fully Anti Clockwise

Repeller Voltage Knob : Fully Clockwise

Meter Switch : Cathode Voltage Position

4. Turn 'ON1 the klystron power supply, CRO and cooling fan.

6. Measure the input voltage and consider it as V1.

CIRCULATOR:

1. Carefully remove the detector setup and insert the circulator as in the set-up, with power fed

through port I.

2. Measure output at port 2 with port 3 terminated in matched load and consider it as V2

3. Now Measure outputs at port 3 with port 2 terminated in matched load and consider it as V2

4. Determine insertion loss and isolation loss by using the readings

RESULT: Operation of circulator is studied and insertion loss and isolation of a circulator ismeasured.

Exp.No: Date:CHARACTERISTICS OF THE MAGIC TEE



19/31


AIM: To study the Magic Tee.

APPARATUS REQUIRED:

1. Klystron Power Supply

2. Klystron Mount

3. Isolator

4. Attenuator

5. Frequency meter

6. VSWR meter7. Magic tee

8. Matched terminations.

MAGIC TEE:

EXPERIMENTAL SETUP:



20/31


For Input measurement

For coupled/isolated measurement:

PROCEDURE:


Isolator

Variableattenuator

FrequencyMeter

DetectorMount

KlystronPowerSupply

KlystronMount CRO

Slotted linesection

Isolator

Variableattenuator

FrequencyMeter

Magictee

KlystronPowerSupply

KlystronMount

Matchedload

Slotted linesection

DetectorMount

CRO

Matchedload


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1. Setup the equipment as shown in fig (a).2. Energize the microwave source for particular frequency and tune the detector mount

for maximum output.

3. Note down the reading as input Voltage.

4.Without disturbing the position of variable attenuator carefully place the Magic tee after slottedline keeping H-arm connected to the slotted line, detector mount to E-arm and matched terminationto arm 1 and 2.note down the reading of CRO .Let it be V4.

5. In the same way measure V1 & V2 by connecting detector on these ports one by one.

6. Determine the isolation between port 3 and 4 dB.

7. Determine the coupling coefficient for port P1& p2.

Result:

Exp.No: Date:VSWR MEASUREMENT



22/31


AIM: To Measure the VSWR and Reflection Coefficient of an Wave Guide..

APPARATUS REQUIRED:

1. Klystron Power Supply2. Klystron Mount

3. Isolator

4. Attenuator

5. Frequency meter

6. CRO

7. Slotted Section

8. Matched terminations.9. Detector Mount

FORMULA:VSWR = V max / V min

EXPERIENTAL SETUP:

PROCEDURE:

1. Set up equipment as shown in fig. Without the directional coupler i.e., directly connect

crystal detector with CRO in order to measure Input after attenuator.


Isolator

Variableattenuator

Frequency

Meter

Detector

Mount

KlystronPowerSupply

Klystron

Mount CRO

Slotted linesection


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3. Keep the control knobs of klystron power supply as below:

Meter switch --- OFF

Mod switch --- AM

Beam voltage knob --- fully anticlockwise.Reflector voltage --- fully clockwise.

AM Amplitude knob --- around fully clockwise.

AM Frequency knob --- around mid position.

4. ON the klystron power supply, CRO and cooling fan .

5. Adjust the probe carriage to measure Vmax and Vmin readings

6. Using formula find out VSWR and Reflection Coefficient

Result : The VSWR and reflection coefficient of an wave guide were determined.

Exp.No: Date:

STUDY OF FIBER OPTIC DIGITAL LINK



24/31


AIM:

The objective of this experiment is to study a Fiber optic digital link. In this experiment you

will study the relation between the input signals & Received signals.

EQUIPMENT REQUIRED:

1. DL-01 Transmitter and Receiver.

2. Power Supply

3. 20MHz Dual Channel Oscilloscope

4. 1MHz Function Generator

5. 1meter Fiber Cable.

Experimental Setup:

PROCEDURE:



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1. Slightly unscrew the cap of LED SFH 756V (660nm).Do not remove the cap from the

connector. Once the cap is loosened, insert the fiber into the cap. Now tight the cap by screwing it

back.

2. Connect the power supply cables with proper polarity to kit. While connecting this,

ensure that the power supply is OFF. Now switch ON the power supply.3. feed the TTL signal of about 1KHz square wave, to IN post of buffer section.

4. Connect the other end of Fiber to detector SFH 551v very carefully as per the

instructions in step.1

5 . Obse r ve t he r ece i ved s i gna l on CRO as O / P .

6. To measure the digital bandwidth of the link, vary the frequency of the input

from100Hz on wards and observe the effect on received signal.

EXPECTED GRAPH:

RESULT:

Exp.No: Date:



26/31


CHARACTERISTICS OF LED

AIM:

To study the Characteristics of a low intensity Optical Source.

APPARATUS:

1. Link-A Kit

2. 1-Meter Fiber Cable

3. Ammeter-1

4. Voltmeter-1

5. CRO - 20 MHz

6. Power supply

7. Jumper connecting wires

SETUP:



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PROCEDURE:

1. Make jumper and switch Settings as shown in the jumper diagram.

2. Connect the ammeter with the jumper connecting wires (JP3).

3. Connect the voltmeter with the jumper wires to JP5 and JP2 as shown in figure.4. Switch on the power supply keep the potentiometer P3 in its minimum position ,P4 is

used to control biasing voltage of the LED.

5. Change S3 position to VI mode.

6. To get the VI characteristics of LED, rotate P3 slowly and measure forward current and

corresponding forward voltage of the LED.

7. Take number of such readings for forward voltage, forward current and calculate optical

power by

Optical power Po= Pi *1.15%

8. Plot the Graphs of forward current and forward voltage, Optical power and Forward

current.

RESULT:

Exp.No: Date:



28/31


STUDY OF LOSSES IN OPTICAL FIBRES

AIM:

1. To study the various types of losses in Optical Fiber.

2. To measure the bending losses in the Optical Fiber3. To measure the Propagation & attenuation loss in the Optical Fiber

EQUIPMENT REQUIRED:

1. Analog Fiber optic trainer Kit (Transmitter & Receiver)

2. Fiber optic links of 1m and 3m length

3. 20Mhz CRO

4. Meter Scale

5. Power Supply

EXPERIMENTAL SETUP:



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EXPERIMENTAL PROCEDURE:

Measurement of Bending Loss:

1. Connect the Circuit as Shown in diagram

2. Connect 1m cable in between the transmitter and receiver.

3. Switch on the power supply.

4. Using function generator set an input signal and observe the output in the CRO.

5. Now turn the optical cable with some radius and observe the output in the CRO

6. Decrease the diameter of the turn and note down the readings.7. Now compare the readings for different diameters.

.

Measurement of Propagation Loss:

1. Connect the Circuit as Shown in diagram

2. Connect 1m cable in between the transmitter and receiver.

3. Switch on the power supply.

4. Using function generator set an input signal and observe the output in the CRO and note

down the readings.

5. Now replace the 1m cable with 3m cable for the same input and note down the readings of

CRO.

6. Now loss can be observed

RESULT:


AL-01 Transmitter AL-01 Receiver

FunctionGenerator

CRO


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Exp.No: Date:

MEASUREMENT OF NUMERICAL APERTURE

AIM:

To Determine the Numerical Aperture of an optical cable.

APPARATUS:

1. Optical Fiber Analog Transmitter kit

2. Numerical Aperture Measurement Unit / NA JIG

3. Measuring Scale4. Power Supply

Numerical Aperture measurement unit



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SETUP CONNECTION:

PROCEDURE:

1. Sl ightly unscrew the cap of LED .Do not remov e the cap f rom the connector.

Once the cap is loosened, insert the fiber into the cap. Now tight the cap by screwing it back.

2. Connect the power supply cables with proper polarity to kit. While connecting

th is , ensure that the power supply is OFF. Now switch ON the power supply.

3. Insert one end of fiber in to NA measurement unit as shown in figure. Adjust the fiber such

that its tip is 0.5cm from the screen.4. Gently tighten the screw to hold the fiber firmly in place.

5. The fiber will project a circular patch of red light on to the screen. Now measure the

diameter of the circular patch of red light in two perpendicular directions (BC and DE in Fig).

The mean radius of the circular patch is given by X = (DE +BC)/4

6. Carefully measure the distance d between the tip of the fiber and the illuminated screen.

The Numerical Aperture of the fiber is given by

NA = Sin () =X/ ( (d2+X2)

7. Repeat steps 3 to 6 for different values of d. compute the average value of Numerical

aperture.

RESULT:

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