DEMONSTRATION on

MICROWAVE AND OPTICAL COMMUNICATION LAB

By

Mr. G. Sivakoteswara RaoAssistant Professor

DEPT. OF E.C.E, VEMU IT CHITTOOR

Topics to be discussed• Vision, Mission, POs, PSOs & PEOs

• Syllabus & Course Outcomes (COs)

• Over view of Microwave

• Bench Setup

• Optical fiber Communication

• Major Equipment List

• Lab Physical View

• Dos & Don’t

• Safety Precautions

Vision, Mission, POs, PSOs & PEOs

Vision of the institute

To be a premier institute for professionaleducation producing dynamic and vibrantforce of technocrat with competent skills,innovative ideas and leadership qualities toserve the society with ethical and benevolentapproach.

Mission of the institute

Mission_1: To create a learning environment with state-of-the art infrastructure, well equipped laboratories, researchfacilities and qualified senior faculty to impart high qualitytechnical education.

Mission_2: To facilitate the learners to foster innovativeideas, inculcate competent research and consultancy skillsthrough Industry-Institute Interaction.

Mission_3: To develop hard work, honesty, leadershipqualities and sense of direction in rural youth by providingvalue based education.

Vision of the Department

To become a centre of excellence in the fieldof Electronics and Communication Engineeringand produce graduates with Technical Skills,Research & Consultancy Competencies, Life-long Learning and Professional Ethics to meetthe challenges of the Industry and evolvingSociety.

Mission of the Department

Mission_1: To enrich Technical Skills of studentsthrough Effective Teaching and Learning practicesfor exchange of ideas and dissemination ofknowledge.Mission_2: To enable the students with researchand consultancy skill sets through state-of-the artlaboratories, industry interaction and training oncore & multidisciplinary technologies.Mission_3: To develop and instill creativethinking, Life-long learning, leadership qualities,Professional Ethics and social responsibilitiesamong students by providing value basededucation.

Programme Educational Objectives ( PEOs)

PEO_1: To prepare the graduates to be able to plan,analyze and provide innovative ideas toinvestigate complex engineering problems of industryin the field of Electronics and CommunicationEngineering using contemporary design and simulationtools.PEO_2: To provide students with solid fundamentals in core and multidisciplinary domain for successful implementation of engineering products and also to pursue higher studies. PEO_3: To inculcate learners with professional and ethical attitude, effective communication skills, teamwork skills, and an ability to relate engineering issues to broader social context at work place.

Programme Outcome (POs)PO_1: Engineering knowledge: Apply the knowledge of mathematics, science, engineering fundamentals, and

an engineering specialization to the solution of complex engineering problems.PO_2: Problem analysis: Identify, formulate, review research literature, and analyze complex engineering

problems reaching substantiated conclusions using first principles of mathematics, natural sciences, andengineering sciences.

PO_3: Design/development of solutions: Design solutions for complex engineering problems and designsystem components or processes that meet the specified needs with appropriate consideration for thepublic health and safety, and the cultural, societal, and environmental considerations.

PO_4: Conduct investigations of complex problems: Use research-based knowledge and research methodsincluding design of experiments, analysis and interpretation of data, and synthesis of the information toprovide valid conclusions.

PO_5: Modern tool usage: Create, select, and apply appropriate techniques, resources, and modernengineering and IT tools including prediction and modeling to complex engineering activities with anunderstanding of the limitations.

PO_6: The engineer and society: Apply reasoning informed by the contextual knowledge to assess societal,health, safety, legal and cultural issues and the consequent responsibilities relevant to the professionalengineering practice.

PO_7: Environment and sustainability: Understand the impact of the professional engineering solutions insocietal and environmental contexts, and demonstrate the knowledge of, and need for sustainabledevelopment.

PO_8: Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms of theengineering practice.

PO_9: Individual and team work: Function effectively as an individual, and as a member or leader in diverseteams, and in multidisciplinary settings.

PO_10: Communication: Communicate effectively on complex engineering activities with the engineeringcommunity and with society at large, such as, being able to comprehend and write effective reports anddesign documentation, make effective presentations, and give and receive clear instructions.

PO_11: Project management and finance: Demonstrate knowledge and understanding of the engineering andmanagement principles and apply these to one’s own work, as a member and leader in a team, to manageprojects and in multidisciplinary environments.

PO_12: Life-long learning: Recognize the need for, and have the preparation and ability to engage inindependent and life-long learning in the broadest context of technological change.

Programme Specific Outcome (PSOs)

PSO_1: Higher Education: Qualify in competitiveexaminations for pursuing higher education byapplying the fundamental concepts of Electronicsand Communication Engineering domains such asAnalog & Digital Electronics, Signal Processing,Communication & Networking, EmbeddedSystems, VLSI Design and Control Systems etc..

PSO_2: Employment: Get employed in alliedindustries through their proficiency in programspecific domain knowledge, specialized softwarepackages and Computer programming or becomean entrepreneur.

Syllabus & Course Outcomes (COs)

JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY ANANTAPURIV B.Tech. I-Sem (ECE)

(13A04710) MICROWAVE & OPTICAL COMMUNICATIONS LABCourse Outcomes (COs)

C418.1:Analyze the various parameters and characteristics of the various waveguide components.C418.2:Analyze working of the various tubes or sources for the transmission of the microwave.C418.3:Acquire knowledge about the measurements to be done at microwaves.C418.4:Explain about the fundamental analogies between electrical and optical communication systems.C418.5:Design light signal of optical sources through current modulation.Minimum Twelve Experiments to be conducted:Part – A (Any 7 Experiments):• Reflex Klystron Characteristics.• Gunn Diode Characteristics.• Attenuation Measurement.• Directional Coupler Characteristics.• VSWR Measurement.• Impedance Measurement.• Waveguide parameters measurement.• Scattering parameters of Directional Coupler.• Scattering parameters of Magic Tee.Part – B (Any 5 Experiments):• Characterization of LED.• Characterization of Laser Diode.• Intensity modulation of Laser output through an optical fiber.• Measurement of Data rate for Digital Optical link.• Measurement of Numerical Aperture.• Measurement of losses for Analog Optical link.• Radiation Pattern Measurement of Antennas (at least two antennas).

VEMU INSTITUTE OF TECHNOLOGY::P.KOTHAKOTANEAR PAKALA, CHITTOOR-517112

(Approved by AICTE, New Delhi & Affiliated to JNTUA, Anantapuramu)Department of Electronics &Communication Engineering

LIST OF EXPERIMENTS TO BE CONDUCTED

• Reflex klystron characteristics• Gunn diode characteristics• Attenuation measurement• Directional Coupler Characteristics• VSWR Measurement • Waveguide Parameters Measurements• Scattering parameters of Magic Tee• Characterization of LED• Characterization of Laser Diode• Measurement of data rate for Digital Optical Link• Measurement of Numerical Aperture• Measurement of losses for Analog Optical Link

ADDITIONAL EXPERIMENTS• Setting up of Analog Optical Link• Measurement of Frequency and Wavelength

Transmission Methodsin Current Communications Networks

Microwave Communicationvs. Optical Fiber Communication

Definition of Microwave

• Microwave is a kind of electromagnetic wave. In a broadsense, the microwave frequency range is from 300 MHz to300 GHz. But In microwave communication, the frequencyrange is generally from 3 GHz to 30 GHz.

• According to the characteristics of microwave propagation,microwave can be considered as plane wave.

• The plane wave has no electric field and magnetic fieldlongitudinal components along the propagation direction.The electric field and magnetic field components arevertical to the propagation direction. Therefore, it is calledtransverse electromagnetic wave and TEM wave for short.

Development of Microwave Communication

Micro Wave Bench Setup

Klystron Power SupplyKlystron power supply, is a state-of-the-art solid-state,regulated power supply for operating low power klystrons.

Features

• Regulated Beam Supply and Repelled Supply voltages.

• LED Digital meter for Beam voltage, current and Repelled voltage.

• Compact and Reliable.

• Modular construction for easy maintenance.

• In addition to AM and FM modulation of beam current, a provision for external modulation is provided.

Klystron Mount Tube

• It is a waveguide of suitable length having octal base on thebroad wall of the waveguide for mounting the klystron tube.

• It consists of movable short at one end of the waveguide todirect the microwave energy generated by the klystron tube.

• A small hole located exactly at the center of the broad wall ofthe waveguide is used to put the coupling pin of the tube asthe electric field vector of EM energy is maximum at thecenter only.

• The maximum power transfer can be achieved by tuning ofthe movable plunger.

Isolator

• An isolator is a two-port device thattransmits microwave or radio frequency power inone direction only.

• It is used to shield equipment on its input side, fromthe effects of conditions on its output side.

• For example, to prevent a microwave source beingdetuned by a mismatched load.

CirculatorA microwave circulator is a three-port, passive RF or microwave device made of magnets and ferrite material which is used to control the direction of signal flow in a RF or microwave circuit.

Attenuator

• The attenuators are basically passive devices which control power levels in microwave system by absorption of the signal.

• Attenuator which attenuates the RF signal in a waveguide system is referred as waveguide attenuator.

• There are two main types fixed and variable.

• They are achieved by insertion of resistive films.

Variable AttenuatorA variable attenuator is a circuit that decreases thestrength of the input signal either continuously orstep by step without appreciable signal distortionwhile substantially maintaining constant impedancematch.

Fixed Attenuator

• Fixed Attenuator is used to reduce power levels ofa signal by a fixed amount with little or noreflections. The output signal is attenuated relativeto the input signal while the input and outputimpedance is maintained close to 50 ohms (or 75ohms) over the specified bandwidth

Frequency Meter

• frequency meter measures frequencies from 3.7 to 12.5 GHz quickly and accurately.

• Its long scale length and numerous calibration marks provide high resolution.

• This is particularly useful when measuring frequency differences or small frequency changes.

• Frequency is read directly in GHz so interpolation or charts are not required.

VSWR Meter

Detector

• The tunable detector is a detector mountwhich is used to detect the low frequencysquare wave modulated microwave signals.The following figure gives an idea of a tunabledetector mount.

• The following image represents the practical application of detector. It is terminated at the end and has an opening at the other end

Gunn Diode

• Gunn diodes are used to build oscillators for generating microwaves with frequencies ranging from 10 GHz to THz.

• It is a Negative Differential Resistance device also called as transferred electron device oscillator

• electron device oscillator is a tuned circuit consisting of Gunn diode with DC bias voltage applied to it.

PIN Modulator

• PIN Diode modulators offer an ideal way foramplitude and the pulse modulation of microwavesignal through wide range of frequencies. Thesemodulators utilize PIN Diode which are mountedacross the waveguide line a R.F. isolated DC bias leadpassing to an external TNC (F) Connectors.

Directional Coupler

• A Directional coupler is a device that samplesa small amount of Microwave power formeasurement purposes.

• The power measurements include incidentpower, reflected power, VSWR values, etc.

• Directional coupler is used to couplethe Microwave power which may beunidirectional or bi-directional.

Magic Tee

• A magic tee (or magic T or hybrid tee) is a hybrid or 3dB coupler used in microwave systems.

• It is an alternative to the rat-race coupler.

• This allows it to be used as a duplexer; for instance, itcan be used to isolate the transmitter and receiver in

a radar system while sharing the antenna.

Optical Communication

• Optical communication is any type ofcommunication in which light is used to carry thesignal to the remote end, instead of electricalcurrent.

• Optical communication relies on optical fibers tocarry signals to their destinations

Block Diagram

A modulator/demodulator, a transmitter/receiver, a light signaland a transparent channel are the building blocks of the opticalcommunications system

Optical Modulator

Optical Receiver

Analog Optical Link

The Fiber Optic Analog Link consists of atransmitter which converts an electrical signalto a light signal, an optical fiber to guide thelight and a receiver which detects the lightsignal and converts it to an electrical signal.Light sources are either light emittingdiodes (LED's) or laser diodes and detectorsare phototransistors or Photodiodes

OFC Cable

OFC Cable

Fiber optic cable is a high-speed data transmission medium. It contains tiny glass or plastic filaments that carry light beams. Digital data is transmitted through the cable via rapid pulses of light. ... Because fiber optic cables transmit data via light waves, they can transfer information at the speed of light

Digital Optical Link

The best digital signal transmission on fiber optics is obtained with DC balanced data containing the same amount of low and high level bits on average, as it is implicitly the case with the clock. For the data line, this is achieved with a special four to five bit encoding and the NRZI (Non Return to Zero with Invert 1 on change) scheme. Basically, this scheme uses a line transition to represent a ``1'' and no transition to represent a ``0''. The idle symbol, which is sent when no other data are pending, is ``11111'', resulting in a square wave output of half the clock frequency.

MAJOR EQUIPMENT DETAILS

DOS & DON’TS• Do not handle the equipment without reading the instructions/Instruction manuals.• Read carefully the power ratings of the equipment before it is switched on. For Indian

equipments, the power ratings are normally 230V/50Hz.If you have equipment with115V/60Hz ratings do not insert power plug, as our normal power supply is 230V/50Hz, Which will damage the equipment. Don’t exceed klystron power supply voltage range above 300v.

• While entering the Laboratory, the students should follow the dress code (Wear shoes, White Apron & Female students should tie their hair back).

• The students should bring their observation note book, practical manual, record note book, calculator, necessary stationary items and graph sheets if any for the lab classes without which the students will not be allowed for doing the practical.

• All the equipments and components should be handled with at most care. Any breakage/damage will be charged.

• If any damage/breakage is noticed, it should be reported to the instructor immediately.• If a student notices any short circuits, improper wiring and unusual smells immediately the

same thing is to be brought to the notice of technician/lab in charge.• Do not wander around the room, distract other students, startle other students or interfere

with the laboratory experiments of others.• Do not chew gum in the laboratory/class rooms.• At the end of practical class the apparatus should be returned to the lab technician and take

back the indent slip.• Each experiment after completion should be written in the observation note book and should

be corrected by the lab in charge on the same day of the practical class.• Each experiment should be written in the record note book only after getting signature from

the lab in charge in the observation note book.• Record should be submitted in the successive lab session after completion of the experiment.• 100% attendance should be maintained for the practical classes.