Mw day 1
-
Upload
ajal-a-j -
Category
Devices & Hardware
-
view
3.822 -
download
0
Transcript of Mw day 1
![Page 1: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/1.jpg)
EC04 - 702: MICROWAVE DEVICES AND COMMUNICATION
By AJAL.AJ
Faculty , Dept of ECEMETS SCHOOL OF ENGINEERING,MALA
![Page 2: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/2.jpg)
1. With this paper, student should be able to understand the working principle and use of various microwave components and semiconductor devices.
This paper also provides the basic aspects of terrestrial and satellite microwave communication
links
Objectives:
2.
![Page 3: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/3.jpg)
Module I (13 hours) Basics of microwave Engineering
• Theory of waveguide transmission - rectangular waveguides - TE modes - TM modes - waveguide components - rectangular cavity resonator - circular cavity resonator (only basic ideas) - E-plane tee - magic tee - isolator - circulator -directional coupler - S matrix
![Page 4: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/4.jpg)
Module II (13 hours)
Microwave tubes
• Microwave linear beam tubes - klystron (bunching, output power and loading) -reflex klystron - traveling wave tube (amplification process, convection current, axial electric field, gain) –
• Microwave crossed field tubes - magnetron (operation, characteristics and applications)
![Page 5: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/5.jpg)
Module III (13 hours) Microwaves devices
• Semiconductor microwaves devices - microwave transistors - tunnel diodes and FETs - transferred electron devices - Gunn effect diodes - (Gunn effect, operation, modes of operation, microwave generation and amplification) - LSA diodes - InP diodes - Cd Te diodes - avalanche transit time devices - read diodes - impatt diodes - trapatt diodes - baritt diodes
![Page 6: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/6.jpg)
Module IV (13 hours) Microwave communication
• Terrestrial microwave communication - basic principles of microwave links -link analysis - microwave relay systems - choice of frequency - line of sight and over the horizon systems - modulation methods - block schematic of terminal transmitters and receivers - effect of polarization - diversity receivers - digital microwave links - digital modulation schemes - fading - digital link design -satellite communication - orbit of communication satellites - angle of elevation - propagation delay - orbital spacing - satellite construction - transponders -antennas - multiple spot beams - earth station - link analysis - multiple accessschemes - digital satellite links
![Page 7: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/7.jpg)
MODULE 1Basics of microwave Engineering
![Page 8: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/8.jpg)
Why Going For New Wave Why Going For New Wave guiding Structures instead guiding Structures instead
of transmission linesof transmission lines
??????
![Page 9: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/9.jpg)
![Page 10: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/10.jpg)
TE & TM ModesTE & TM Modes
![Page 11: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/11.jpg)
![Page 12: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/12.jpg)
![Page 13: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/13.jpg)
Rectangular Waveguides Rectangular Waveguides (Derivation of fields EX ,Ey ,Hx & (Derivation of fields EX ,Ey ,Hx &
Hy)Hy)
![Page 14: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/14.jpg)
Waveguide components
Rectangular waveguide
Waveguide to coax adapter
E-teeWaveguide bends
![Page 15: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/15.jpg)
COORDINATES OF CIRCULAR CAVITY RESONATOR
![Page 16: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/16.jpg)
![Page 17: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/17.jpg)
METHODS OF EXCITATION
![Page 18: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/18.jpg)
![Page 19: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/19.jpg)
WHY GOING FOR SCATTERING PARAMETERS IN CASE OF
MICROWAVE NETWORKS ???
![Page 20: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/20.jpg)
![Page 21: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/21.jpg)
![Page 22: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/22.jpg)
Waveguide Tees :
a.E Plane Teeb.H Plane Teec.Magic Tee
![Page 23: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/23.jpg)
![Page 24: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/24.jpg)
![Page 25: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/25.jpg)
![Page 26: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/26.jpg)
MICROWAVE HYBRID CIRCUITS
• MICROWAVE JUNCTION: Interconnection of two or more devices
1.WAVE GUIDE TEES 2.DIRECTIONAL COUPLER3.CIRCULATOR
![Page 27: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/27.jpg)
MICROWAVE ISOLATOR
![Page 28: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/28.jpg)
![Page 29: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/29.jpg)
CIRCULATOR
![Page 30: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/30.jpg)
![Page 31: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/31.jpg)
Directional Coupler
![Page 32: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/32.jpg)
Contrast the ideal & Contrast the ideal & practical directional practical directional coupler!!!coupler!!! ideal ideal - infinite directivity - infinite directivity
practical practical directional coupler directional coupler
30 to 35 dB30 to 35 dB
![Page 33: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/33.jpg)
TWO HOLETWO HOLE FOUR FOUR HOLEHOLE
SCHWINGERSCHWINGER BETHE HOLEBETHE HOLE
TYPES OF DIRECTIONAL COUPLERTYPES OF DIRECTIONAL COUPLER
![Page 34: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/34.jpg)
Typical Directional Coupler Typical Directional Coupler constructed Using Micro strip constructed Using Micro strip LineLine
![Page 35: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/35.jpg)
Typical Directional Coupler Typical Directional Coupler constructed Using RECT constructed Using RECT WAVEGUIDESWAVEGUIDES
![Page 36: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/36.jpg)
MODULE 2Microwave tubes
![Page 37: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/37.jpg)
Microwave Tubes
• Used for high power/high frequency combination
• Tubes generate and amplify high levels of microwave power more cheaply than solid state devices
• Conventional tubes can be modified for low capacitance but specialized microwave tubes are also used
![Page 38: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/38.jpg)
Evolution of microwave tubes• 1935 – Heil oscillator• 1939 – klystron amplifier• 1944 – Helix type TWT• In the early 1950s – low power output of linear
beam tubes to high power levels• Finally invention of Magnetrons• Several devices were developed – two
significant devices among them are
1) extended interaction klystron2) Twystron hybrid amplifier
![Page 39: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/39.jpg)
SIGNAL SOURCES THAT GENERATE POWER
Microwave tubes
@Frequency > 1GHz
E.g.: klystron, Traveling WaveTube, magnetron
conventional vacuum tubes @
frequency < 1GHzE.g. : triodes, tetrodes,
pentodes
![Page 40: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/40.jpg)
What are all the constraints of ordinary vacuum tubes at
frequencies beyond 1 GHz????
![Page 41: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/41.jpg)
The limitations of conventional vacuum tubes at frequencies
beyond 1 GHz :
• Lead inductance and inter electrode capacitance effects
• Transit Angle Effects• Gain-Bandwidth product limitations
![Page 42: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/42.jpg)
Types of Microwave Tubes
Linear beam tubes (O – Type)
Crossed Field Tubes (M – Type)
Eg: Klystron Reflex klystron TWT
Eg: Magnetron
![Page 43: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/43.jpg)
Linear beam devices Crossed field devices
(I) Straight path taken by the electron beam
A principle feature of such tubes is that electrons travel in a curved path
(i) DC magnetic field is in parallel with DC electric field to focus the electron beam
DC magnetic field is perpendicular to DC electric field
![Page 44: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/44.jpg)
Types of Linear Beam Tubes
TWYSTRON
MULTICAVITY KLYST
TWOCAVITY KLYST
LINEAR BEAM TUBES
KLYSTRON TUBES
HYBRID TUBES
TRAVELING WAVE TUBES
REFLEX KLYST
LADDE-RTRON
HELIX RING- BAR TWT
COUPLED CAVITY
TWT
HELIX BWO
![Page 45: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/45.jpg)
TWYSTRON• KLYSTRON + TWT = TWYSTRON
• It is hybrid amplifier that uses the combinations of klystron and TWT components
![Page 46: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/46.jpg)
![Page 47: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/47.jpg)
![Page 48: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/48.jpg)
Velocity Modulation
PRINCIPLE
• Electric field from microwaves at buncher alternately speeds and slows electron beam .
• This causes electrons to bunch up Electron bunches at catcher induce microwaves with more energy.
• The cavities form a slow-wave structure
![Page 49: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/49.jpg)
![Page 50: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/50.jpg)
![Page 51: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/51.jpg)
![Page 52: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/52.jpg)
Magnetron Oscillator
![Page 53: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/53.jpg)
![Page 54: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/54.jpg)
TYPES OF TRAVELING WAVE MAGNETRON
• CYLINDRICAL • LINEAR • COAXIAL• VOLTAGE-TUNABLE• INVERTED COAXIAL• FREQUENCY-AGILE COAXIAL
![Page 55: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/55.jpg)
33
Narrow Pulse Magnetron SystemNarrow Pulse Magnetron SystemAt H6 Systems Before ShippingAt H6 Systems Before Shipping
![Page 56: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/56.jpg)
2121
Narrow Pulse Magnetron SystemNarrow Pulse Magnetron SystemNaval Electromagnetic Radiation FacilityNaval Electromagnetic Radiation Facility
![Page 57: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/57.jpg)
CHARECTRISTICS OF MAGNETRON ````
1. EFFICIENCY η = 40 to 70%2. POWER OUTPUT ( 800KW )3. OPERATING FREQUENCY
( UPTO 10GHZ )
![Page 58: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/58.jpg)
MODULE 3Microwave Devices
![Page 59: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/59.jpg)
Microwave Devices
• A semiconductor device for the generation or amplification of electromagnetic energy at microwave frequencies.
DEFINITION…
![Page 60: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/60.jpg)
![Page 61: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/61.jpg)
![Page 62: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/62.jpg)
![Page 63: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/63.jpg)
![Page 64: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/64.jpg)
![Page 65: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/65.jpg)
![Page 66: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/66.jpg)
![Page 67: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/67.jpg)
![Page 68: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/68.jpg)
![Page 69: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/69.jpg)
![Page 70: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/70.jpg)
![Page 71: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/71.jpg)
![Page 72: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/72.jpg)
![Page 73: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/73.jpg)
![Page 74: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/74.jpg)
![Page 75: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/75.jpg)
![Page 76: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/76.jpg)
![Page 77: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/77.jpg)
![Page 78: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/78.jpg)
![Page 79: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/79.jpg)
![Page 80: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/80.jpg)
![Page 81: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/81.jpg)
![Page 82: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/82.jpg)
![Page 83: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/83.jpg)
![Page 84: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/84.jpg)
![Page 85: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/85.jpg)
![Page 86: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/86.jpg)
![Page 87: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/87.jpg)
![Page 88: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/88.jpg)
![Page 89: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/89.jpg)
![Page 90: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/90.jpg)
![Page 91: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/91.jpg)
![Page 92: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/92.jpg)
![Page 93: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/93.jpg)
![Page 94: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/94.jpg)
![Page 95: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/95.jpg)
![Page 96: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/96.jpg)
![Page 97: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/97.jpg)
![Page 98: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/98.jpg)
Leo EsakiThe Nobel
Prize in Physics 1973
A NEGATIVE RESISTANCE DEVICE
![Page 99: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/99.jpg)
![Page 100: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/100.jpg)
![Page 101: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/101.jpg)
![Page 102: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/102.jpg)
![Page 103: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/103.jpg)
![Page 104: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/104.jpg)
![Page 105: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/105.jpg)
APPLICATIONS
![Page 106: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/106.jpg)
• Because of negative resistance in the forward characteristics, the device can be used actively as an oscillator
• Tunnel diode symbol
![Page 107: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/107.jpg)
- Ve Resistance Region
VfVp
Ip
Vv
Forward Voltage
Reverse voltage
Iv
Rev
erse
C
urre
nt
Forw
ard
Cur
rent
Ip:- Peak Current; Iv :- Valley Current; Vp:- Peak Voltage
Vv:- Valley Voltage; Vf:- Peak Forward Voltage
I V - CHARACTERISTIC OF TUNNEL DIODE
p
V
![Page 108: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/108.jpg)
GUNN DIODE
![Page 109: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/109.jpg)
• Ridley and Watkins proposed in 1961• Hilsum calculated the transferred electron effect in III-V in 1962; experiment fails.• J.B. Gunn of IBM discovered the so-called Gunn effect in 1963 and rejected the above theory.• Kroemer explained the origin of the negative differential mobility is
Ridley-Watkins-Hilsum’s mechanism
![Page 110: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/110.jpg)
![Page 111: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/111.jpg)
![Page 112: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/112.jpg)
![Page 113: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/113.jpg)
![Page 114: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/114.jpg)
![Page 115: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/115.jpg)
Avalanche Transit-time DevicesATD ’s
• IMPATT Diode (IMPact IonizationAvalanche Transit Time Diode)
• TRAPATT diode (Trapped plasma avalanche triggered transit-time )
• BARRITT diode (Barrier injection transit-time diode )
READ DIODE
![Page 116: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/116.jpg)
READ DIODE
• The basic operating principle of IMPATT diode can be understood by studying the structure proposed by READ in 1959 known as READ diode
• A read diode structure , doping profile and DC electric field distribution is shown in fig
![Page 117: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/117.jpg)
READ DIODE
![Page 118: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/118.jpg)
MICROWAVE CAVITY FREQUENCY TUNING
![Page 119: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/119.jpg)
IMPATT DIODE
![Page 120: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/120.jpg)
![Page 121: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/121.jpg)
![Page 122: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/122.jpg)
![Page 123: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/123.jpg)
TRAPATT DIODES
![Page 124: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/124.jpg)
Voltage & current
waveforms of trapatt
diode
![Page 125: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/125.jpg)
BARRIER-INJECTION TRANSIT-TIME DIODE
BARITT
![Page 126: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/126.jpg)
History
transit-time delay 에 의한 negative differential resistance 를 얻는 idea (Schockely ,1954)
additional phase delay 를 소개하기 위한 avalanche current 사용 (Read ,1958) 실험적으로 밝힘 (Johnston et al ,1965) BARITT mode operation (Ruegg, Wright, 1968) BARITT diode 를 처음으로 만듦 (coleman, Sze, 1971)
![Page 127: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/127.jpg)
Structure P-n junction, Schottky barrier, or 이 둘의
조합으로
Doping level : 0.5~10um
Substrate 는 low series resistance 때문에 변질됨
Series resistance 로부터 power dissipation 을 줄이기 위해서 가끔 substrate 는 10um 보다 두꺼워 짐
![Page 128: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/128.jpg)
![Page 129: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/129.jpg)
FGV
![Page 130: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/130.jpg)
Characteristic
전압이 depletion edge meet 까지 가면 , punch-through 가 일어남
Junction 이 asymmetrical 하면 , Vpt≠V‘pt
이러한 characteristic 은 negative differential resistance or negative dV/dI 에서는 일어나지 않음
![Page 131: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/131.jpg)
Characteristic Punch-through 에서 전압
Flat-band condition 에서 전압
V1= injecting junction 을 지나는 공급된 전압의 일부
Injection current
s
biD
s
Dpt
qNLLqNV
22
2
s
DFB
LqNV2
2
FB
FBIbi V
VVV4
2
4
)(expexp*
1exp)(
exp*
22
2
FB
FBbpp
Ibibppp
kTVVVq
kTq
TA
kTqV
kTq
TAJ
![Page 132: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/132.jpg)
Characteristic Charge Q 가 주어진 후
에 , saturation velocity 로 substrate 를 돌아다님
Terminal current
Frequency
LQvI sat
Lvf sat
43
satv
![Page 133: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/133.jpg)
Characteristic
![Page 134: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/134.jpg)
Application Microwave generator
- tank circuit 에 connected, oscillator 는 dc source 로부터 microwave ac signal 로 바꿔줌
- microwave power source = burglar, proximity system 장점 – low noise level. Low voltage operation 단점 - reduced efficiency, lower output power Voltage limiter
![Page 135: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/135.jpg)
Related Device1) Double-Velocity Transit-Time diode (DOVETT)
• 유일한 특징은 saturation velocity가 두 가지 값을 가진다는 것
• Heterojunction
• Injection current - thermionic emission, tunneling
![Page 136: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/136.jpg)
Related Device2) Tunnel-Injection Transit-Time Diode ( TUNNETT )
• Injection current – tunneling (high field : 1MV/cm)• structure – one junction• Vicinity of injecting junction – higher doping level• n+-layer – doping : 1019cm-3 , thickness : 10nm• 장점 – high frequency capability (1000GHz), low voltage (2V)
![Page 137: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/137.jpg)
Related Device3) Quantum-Well-Injection Transit-Time Diode
(QWITT)
• Injection current – tunneling• Higher frequency (TUNNETT)• negative differential resistance
Resonant tunneling mechanism
![Page 138: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/138.jpg)
MODULE 4
Microwave communication
![Page 139: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/139.jpg)
MODULE 4
• IT’S ALL ABOUT TWO COMMUNICATION SYSTEMS:
1. TERRESTRIAL MICROWAVE COMMUNICATION SYSTEM
2. SATELLITE MICROWAVE COMMUNICATION SYSTEM
![Page 140: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/140.jpg)
140
History of Communication Satelite
• In 1964,the Intelsat Consortium was formed to operate and maintain the International Telecommunication Satellite System.
• In 1965,the first commercial satellite Intelsat I (Early Bird) was launched.
• In 1967-1968, it was followed by Intelsat II and Intelsat III respectively.
• In 1971, it was followed by Intelsat IV.• As of 1982, there were some 400 earth stations with over 55,000
channels using the Intelsat System.
19861980 1989 1992
![Page 141: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/141.jpg)
Some of the everyday Technologies that depend on radio waves:
• AM and FM radio broadcasts • Cordless phones • Garage door openers • Wireless networks • Radio-controlled toys • Television broadcasts • Cell phones • GPS receivers • Ham radios • Satellite communications • Police radios • Wireless clocks
![Page 142: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/142.jpg)
STRUCTURE OF ATMOSPHERE
![Page 143: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/143.jpg)
Ion.. layers
![Page 144: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/144.jpg)
![Page 145: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/145.jpg)
![Page 146: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/146.jpg)
IN IONOSPHERIC PROPAGATION
• SINGLE HOP• MULTIHOP
• F c = (N max)^ ½Fc CRITICAL FERQUENCYN max MAXIMUM ELECTRON DENSITY
![Page 147: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/147.jpg)
MODES OF PROPAGATION
![Page 148: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/148.jpg)
EM SPECTRUM
• Electromagnetic waves has been classified into several ranges of frequencies
• Very low frequency (3 kHz to 30 kHz)• Low frequency (30 kHz to 300 kHz)• Medium frequency (300 kHz to 3000 kHz) &
so on
![Page 149: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/149.jpg)
• Even though the frequency range is very vast ; the propagation of these frequencies
through the free space can be grouped into 3 distinct modes:
1. The ground wave propagation 2. The sky wave propagation 3. The space wave propagation
![Page 150: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/150.jpg)
1. Ground wave propagation
• Radio waves below 3 MHz which includes VLF, LF & MF – propagated through the surface of the earth
• This form of prop. Is “Ground wave propagation”
![Page 151: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/151.jpg)
2.Sky wave propagation
• Freq.'s in the range of 3 MHz to 30 MHz – propagated through the ionosphere
• The propagation of these waves are said to be “sky wave propagation”
![Page 152: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/152.jpg)
3.Space wave propagation
• At the freq.’s above 30 MHz – propagated through the troposphere
• These waves are called as “space waves” or “tropospheric” waves
• The propagation of these waves are said to be “space wave propagation”
![Page 153: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/153.jpg)
MORE ABOUT SPACE WAVE PROPAGATION....
• LOS path• Ground reflected path
![Page 154: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/154.jpg)
Repeaters
![Page 155: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/155.jpg)
DIVERSITY RECEPTION SCHEMES
![Page 156: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/156.jpg)
(a) Frequency diversity technique
![Page 157: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/157.jpg)
(b) Space diversity technique
![Page 158: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/158.jpg)
(c) Polarization Diversity
• A single RF carrier is propagated with two different electromagnetic polarization
• This is achieved by using vertically & horizontally polarized antennas at the transmitter and receiver
• The idea is that EM waves of different polarization may not experience the same transmission degradation
• may be used with space diversity
![Page 159: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/159.jpg)
Fig: Antenna Arrangement in space diversity reception
![Page 160: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/160.jpg)
Multipath Interference
![Page 161: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/161.jpg)
Fading
![Page 162: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/162.jpg)
Four types of fading:
1. absorption fading2. reflection multipath fading3. atmospheric multipath fading and 4. sub-refraction fading
![Page 163: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/163.jpg)
(b) Reflection multipath fading
![Page 164: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/164.jpg)
(c) Atmospheric multipath fading
![Page 165: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/165.jpg)
(d) Sub refraction fading
![Page 166: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/166.jpg)
What is a Spot Beam?
• A spot beam is a satellite beam which is focused on a relatively small portion of the earths surface.
![Page 167: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/167.jpg)
Uplinking Antenna
Satellite
IMD Server,Delhi
LAYOUT FOR DATABROADCAST
WORLD SPACE RECEIVER
DDA
128 Kbps
PC
PC
Remote Sites
INTERNET
OPTION-2
World Space Server,Singapore
(currently)
OPTION -1Dedicated 64Kbps link
to be provided by VSNL
PC Card with built-in
Receiver &
DDA
64Kbps Local Leased line Connectivity
![Page 168: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/168.jpg)
![Page 169: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/169.jpg)
FACTORS AFFECTING MW LINK
Following major phenomenon affect MW Link
• 1. REFLECTION• 2. REFRACTION• 3. DIFFRACTION• 4. SCATTERING• 5. ABSORPTION
![Page 170: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/170.jpg)
Terrestrial Microwave Antennas
![Page 171: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/171.jpg)
![Page 172: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/172.jpg)
![Page 173: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/173.jpg)
![Page 174: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/174.jpg)
The principle of troposcatter radio communications
![Page 175: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/175.jpg)
Optical and Radio Horizons
![Page 176: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/176.jpg)
Fig: Effect of atmospheric refraction
![Page 177: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/177.jpg)
![Page 178: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/178.jpg)
![Page 179: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/179.jpg)
![Page 180: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/180.jpg)
![Page 181: Mw day 1](https://reader033.fdocuments.us/reader033/viewer/2022061306/58f9aadb760da3da068b7d79/html5/thumbnails/181.jpg)
THANK YOU