National Taiwan University of Science and Technology Department of Electronic Engineering - PowerPoint PPT Presentation

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National Taiwan University of Science and Technology Department of Electronic Engineering

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Example Plot the radiation pattern of a parabolic antenna with a diameter of 8.5 m and ... – PowerPoint PPT presentation

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Title: National Taiwan University of Science and Technology Department of Electronic Engineering


1
National Taiwan University of Science and
TechnologyDepartment of Electronic Engineering
????????
???????? 98 ?8?25?
98?8?25?
2

????
??????????(Introduction) ??????(Satellite
Orbits) ??????(Communication Satellites) ???????(E
arth Stations) ?????????(Communication
Quality) ????????(Applications) ????
Reference G. MARAL, M. BOUSQUET, Satellite
Communications Systems Systems, Techniques and
Technology, JOHN WILEY SONS, 3rd, 1998.
2
98?8?25?
3
????????
?????????? GEO(????)?MEO?LEO??, ???????????????
Global),???(Regional)? ??(Domestic)?
2016?4?16?
3
98?8?25?
4
??????
??????(Spectrum)???(Frequency Band)???????(Wave
Band),????
?? ????(ƒ) ?? ????(?)
???(VLF) 1030KHz ??? 3010Km
? ?(LF) 30300KHz ? ? 101Km
? ?(MF) 3003,000KHz ? ? 10.1Km
? ?(HF) 330MHz ? ? 10010m
???(VHF) 30300MHz ??? 101m
???(UHF) 3003,000MHz ??? 10.1m
???(EF) 330GHz ??? 101cm
????(VEF) 30300GHz ???? 10.1cm
?
98?8?25?
5
??????
  • ?????????????????
  • ????/??????????
  • ??????????????????????
  • ???????????????????
  • ??????????,???????
  • ????????0.25???????
  • ????????Doppler effects?

98?8?25?
6
?????? (??????)
Space Segment
??
??
????
???
TTC Ground station
Ground Segment
????
????
????
98?8?25?
7
?????? (?????)
98?8?25?
8
????????
????
??????? ??(SOCC))
????????? (GOCC)
C
C
???? (WAN)
?????? ????
?????
T1
E1
L
S
???????? GSM/AMPS
???????? PSTN
?????? ????
?????
????????
98?8?25?
9
????
  1. ??????????????????????????????????????????
  2. ???????????????????????????,???90??,????????????
    ??????????????
  3. ???????0?90????,??????????????????,?????????????
    ??????
  4. ???????00?,???????????????????(Stationary
    Satellite)???????(Geosynchronous Orbit)?????

98?8?25?
10
??????
  • ????(Geostationary Earth Orbit GEO)
  • ?/???(Low/Medium Earth Orbit LEO/MEO)
  • ????(Elliptical Orbit)
  • ????(Inclined Orbit)

???
????
?/???
N
??
35,786??

???
S
????
98?8?25?
11
????????
  1. ??????????????760???1430??670?????????????????????
    ???
  2. ?????????????????????50???,??????1210,????630,????
    1800???????????????
  3. ???????????????????,???????????????30???????,?????
    ????125 ms(1/8?),???????????,??????????250
    ms??????,???????????????????
  4. ????????????,?????????????????????,???????????????
    ?????????????????,Echo?????,?????????,????????????

98?8?25?
12
????????
98?8?25?
13
??????
  • ????????????C??,6 GHz?????(up link)?4
    GHz?????(down link)?Ku??,14 GHz??????12
    GHz???????

98?8?25?
14
?????
?? flt10 GHz????? ?????,????? ????Faraday
Rotation ??? Fgt10 GHz?,?? ???????,???? Faraday
Rotation????? ???,???????? ??,????????? ??,??XPI??
??, ???????????
Emax
Emin
Horizontal
Vertical
LHCP
Elliptical
RHCP
98?8?25?
15
????????
???? ????
??
??
????
(a)?/????????????
??????3?20? ?????9?23?
??????
A
??
??
B
(b)?/???????????????
98?8?25?
16
??????Foot print maps
98?8?25?
17
???????
??
??
??
Onboard processing ISL
TDMA/PSK CDMA/PSK
FDMA/FM SCPC/FM
???
Onboard switching
Global Network
????
Frequency re-use Demand assignment
30/20 GHz optic ISL
VII,VIII
IRIDIUM GLOBALSTAR
????
Scanning beams switch matrix
SS-TDMA
????? ??
VI
ACTS,ITALSAT OLYMPUS
14/12 GHz
????
TVSAT,TDF TELE-X,BSB
Transponder Hopping
V
????
Beam forming
IV
EURELSAT 1 TELECOM 1 SBS
????? ????????
Multi Spot Beam
INTELSAT I,II,III
???
???? (L-band)
6/4 GHz
INMARSAT
Global Beam
???? ?????
???
1965
1965
2000
98?8?25?
18
END-TO-END COMMUNICATION LINK
CONNECTION BY TERRESTRIAL NETWORK
SATELLITE
(C/N0)T
PROCESSING
MOD
IF/RF
PROCESSING
MOD
IF/RF
S/N or BER
SATELLITE NETWORK
NETWORK/STATION INTERFACE
NETWORK/STATION INTERFACE
TERRESTRIAL NETWORK
TERRESTRIAL NETWORK
TERMINAL/NETWORK INTERFACE
TERMINAL/NETWORK INTERFACE
USER
USER
TERMINAL
TERMINAL
98?8?25?
19
????????
????
A?
B?
?????
?????
????
?????
?????
?????
?????
?????
?????
?? ???
?? ???
??
??
98?8?25?
20
??????(Satellite Orbits)
  • ?????????????????(??????)
  • ????(Elliptical orbits)
  • ?????????????,?????????????
  • ????(Equal areas covered)
  • ????????,????????????????????
  • ????(Orbital period)
  • ?????????????????? ????
  • T2(2p)2 a3/GM M????? G?????
  • GM?3.986x105km3/s2

98?8?25?
21
???????????????
???
?? 3.075 Km/s
41,756 km
17.340
  • ????????
  • ??71.320 ??71.320
  • (???????1/3??)

18,101 km (at equator)
73,155 km
?????????
??
????? (?????)
35,786 Km
12,752 Km
???
???
98?8?25?
22
????(Orbital parameters)
z
Orbital plane
Inclination,i
Ascending node
y
Equatorial plane
w
argument of perigee
x
W
longitude of ascending node
98?8?25?
23
????
98?8?25?
24
??????
????
????A?????? ????B????? (36,000
Km)/(3x108m/sec) x 2 0.25 ?
?????
Ionospheric Reflect
?????
Tropospheric Scatter
????
Radio Relay
50 Km
750 Km
1,500 Km
???? A
???? B
10,000 Km
98?8?25?
25
????????
????????????????????? ????????????????????
98?8?25?
26
??????????
FDMA Frequency Division Multiple
Access
TDMA Time Division Multiple Access
CDMA Code Division Multiple
Access Sometimes called Spread Spectrum Multiple
Access.
98?8?25?
27
???????
(a)????????
(b)?????????,???? ?????,???????????
(c)???????????? (Link), ??????????????????
(d) The stations are distributed between the
two satellites. The intersatellite link carries
the traffic between the two groups of stations.
98?8?25?
28
??????
??????????
(a)?????????? ????
(b)?????????????? ??????? (?????)?
(c)??????terrestrial networks ?? ??????? (?????)?
98?8?25?
29
???????
??????
??????
98?8?25?
30
????
98?8?25?
31
?????????
??????HPA (High Power Amplifier)?,????????
98?8?25?
32
??VSAT??
  • VSAT?Very Small Aperture Terminal???,?????????????
    ?
  • VSAT??????????????1-3?????????????????????????????
    ?????,??????????????????,?????,?????????????????,?
    ?????????VSAT?????

98?8?25?
33
?????(LEO)
98?8?25?
34
?????(LEO)
  • ???? ????
  • Iridium (785km??) 37?? (66?/6??)
  • Globalstar(1401km) 15?? (48?/8??)
  • Odyssey 18??
  • Inmarsat-P 26??
  • (CHT??? Globalstar)
  • (??????Iridium)

98?8?25?
35
??????????
????
???
???
????
???
???
TTC??
???
???
????
?????????
????
???
????
?????
????
AKM
???
?????????
?????
???
?
Apogee motor
Thruster
?????
98?8?25?
36
????????
Typical diagram of a transponder
98?8?25?
37
????????
Satellite wideband receiver
98?8?25?
38
????
6/4 GHz hemi 6/4 GHz zone
14/11 GHz spot
98?8?25?
39
???????(Earth Stations)
98?8?25?
40
???????(VSAT)
Parabolic Antenna
???
????
Coaxial Cable
98?8?25?
41
?????????
Ground Communications Equipment
RF Equipment
Antenna subsystem
??????
14/6 GHz
BPSK/QPSK
????
HPA
Mod.
Upconv.
Feed system
Interface
Base band processing
AZ,EL,POL
LNA
Demod.
Downcov.
??????
commands
??????
IF 70/140 MHz
12/4 GHz
??????
????
Power supply
Pointing data input
98?8?25?
42
?????????
A home terminal for DBS TV reception
98?8?25?
43
?????????
A master antenna TV (MATV) system
98?8?25?
44
?????????
An indoor unit of a community antenna TV
45
??VSAT??
  • VSAT?Very Small Aperture Terminal
    ???,??????????????
  • VSAT??????????????1-3?????????????????????????????
    ?????,??????????????????,?????,?????????????????,?
    ?????????VSAT?????

98?8?25?
46
?????????(VSAT Network)
??
???
???
???
???
???
???
???
???
???
98?8?25?
47
???????? (Link Budget)
Uplink thermal noise NoU
EIRPPdGd
G/T
Intermodulation noise NoIM
Uplink interference NoiU
CU
Rain attenuation
Downlink interference NoiD
Downlink
Uplink
Downlink thermal noise NoD
Free space loss
CD
G/T
EIRPPtGt
Overall link
98?8?25?
48
?????????
  • ???????????Maxwells Equations.

  • (From Faradays law)

  • (From Amperes law)

  • (From Gauss law)

  • (No 0agnetic charges)

  • (Continuity equation)

98?8?25?
49
???????????
???? ???? ????
????????? ???????? ??10GHz?????
????? ?????? C?Ku????????(???????)
????????? ???? ????????
???? ??????????? ??????? 10GHz???????10GHz?????
????????? ?????????? ??????
??????? ??????? ?????????
50
????????
???????????
??????
98?8?25?
51
????????
???????????(Front end)?????.
Noise analysis of a microwave receiver front end,
including antenna and transmission line
contributions.
98?8?25?
51
52
??(Antenna)????
  • Antenna A device used to efficiently transmit
    and/or
  • receive electromagnetic waves.
  • IEEE std 145 (1973)a mean for radiating or
    receiving
  • radio waves.
  • 1. An antenna may be a single straight wire or a
    conducting loop excited by a voltage source, an
    aperture at the end of a waveguide, or a complex
    array of these properly arranged radiating
    elements.
  • 2. ???? ????, ??(directivity), ???? ????.

98?8?25?
53
????
98?8?25?
54
??????
?????????????,????????? ?????????????,????????,???
??????????,??????????????????????????????????????,
??,????????????????????????????????????????
98?8?25?
55
??????
Aeff Effective antenna aperture.
For a circular aperture antenna.
where D circular aperture diameter.
Angular beamwidth
(degrees)
98?8?25?
56
????????Example
  • Plot the radiation pattern of a parabolic antenna
    with a diameter of 8.5 m and operating frequency
    of 2836 MHz. The radiation E-field is given by
    the following equation
    , where first-order Bessel function
    which is given by the following power series
    equation.
  • where Gamma function
    .

98?8?25?
57
????????Example
  • From the plot of radiation pattern, discuss
    the HPBW of main lobe and first and second side
    lobes, BWFN, the directions (or angles) of first
    and second side lobes maxima and the values of
    these two side lobes maxima relative to the main
    lobe.

Gain 38727 (45.88dB)
HPBW 0.72 (deg)
BWFN 1.74 (deg)
98?8?25?
58
??????
  • ?????????????
  • ?Pt?????????,?????Pr???

98?8?25?
59
??????????---????
Thermal noise (Nyquist or Johnson noise) for a
resistor R
Equivalent Noise Temperature
Equivalent Noise Temperature
98?8?25?
60
??????????---????
Transmission Line
Equivalent Noise Temperature
Noise Figure (NF)
Equivalent Noise Temperature
When the line is at room temperature and the
noise figure reduces to NF L.
where To 290 oK.
98?8?25?
61
??????????---????
A cascaded stage system
Equivalent Noise Temperature
98?8?25?
62
??????????---????
The overall gain
The output noise power
The overall noise figure of the system
98?8?25?
63
??????????---????
Which connection is better?
Connection used in examples illustrating overall
noise temperature of system
98?8?25?
64
????????
?????????????????????????????????????????????,????
??????????????,??????????,?????????? ??PT ????
GT?????? GR?????? LFS???????? R????
?????
  • EIRP Effective isotropically radiated power

Power flux density
??????
??
Free space loss
?????????LA,????????,??????
??????
98?8?25?
65
????????
???????????(Path loss is defined as)
Friis free space loss equation,????????

??????
??L????????????????????.
98?8?25?
66
Satellite and Earth-Station Antenna Alignment
Some gain loss due to misalignment
Maximum gain
67
????????
???????????? ?EIRPPtGt34dBW2.512 103
Watts ????4.0GHz????????2 m ?????????36km ????3
6dB ??
???????????? Pr2.910-7 Watts or
35.38dBm (EIRP Effective Isotropically Radiated
Power)
98?8?25?
68
????????
???(noise floor)
??
(Boltzmanns constant)
??
T0 ambient temperature (290 300
oK) BW ??(bandwidth) NF ???(noise
figure) ????NF 9 dB ???????30 kHz. ???(noise
floor)??
Link Budget
98?8?25?
68
69
????????
??? ??, ?????(????)????? (figure of
merit),???????,Ts ??????????? (????
)
98?8?25?
70
????????
  • dB (?????)
  • ???
  • ?????P11mW,????????dBm.
  • ???dB (?????)
  • ?????V11mV,????????dBmV.
  • ??ln(V2/V1)????Nepers (Np)
  • 1 Np 10log e2 8.686 dB.
  • ????? 1W0 dBW30 dBm, 4 W6 dBW
  • 36 dBm and 15 mV??23.52 dBmV.

NoiseThermal noise?Intermodulation
noise?Crosstalk Impulse noise Atmospheric
absorption, Multipath Refraction
98?8?25?
71
??????C/N??
  • C/NEIRP PL G 10logTsys 10logBW 228.6
    (dB)(1)
  • ?? PL Path Loss
  • 196.3 dB for C-??,205.8 dB for Ku-???
  • EIRP ??????? (dBW)
  • G ?????? (dB)
  • Tsys ???????????(oK)
  • B ?????????(Hz)?
  • G 10logTsys?????? ?????????(Figure of
    Merit), ?????????????????????(1)??,????????
    ??????????,??????????,??????????

98?8?25?
72
????????
???? ????
??
??
????
(a)?/????????????
??????3?20? ?????9?23?
??????
A
??
??
B
(b)?/???????????????
98?8?25?
73
????????(Applications)
Cellular backbone
Corporate Network
Telecommuniting
Telemedicine
Video Conference
Video Conference
Existing Terrestrial Network
Internet Connection
Distance Learning
98?8?25?
74
??????
???? Individual reception
???? Community reception
????? Studio
??? Uplink station
98?8?25?
75
DirecPC??????
ST-1
?
?
?
ISP
?
PSTN
?
?
????????? ????????
Internet
?
?
WEBSITE
DirePC????????
98?8?25?
76
??????
????
??????? ??(SOCC))
????????? (GOCC)
C
C
???? (WAN)
?????
?????? ????
T1
E1
L
S
???????? GSM/AMPS
???????? PSTN
?????? ????
?????
????????
98?8?25?
77
?????????(Footprint)
  • ??????
  • ???(Global)
  • ????(Hemisphere
  • Beam)
  • ????(Zone Beam)
  • ????(Spot Beam)

East Spot
West Spot
East Zone
West Zone
East Hemi.
West Hemi.
Global
98?8?25?
78
????????
????
A?
B?
?????
?????
????
?????
?????
?????
?????
?????
?????
?? ???
?? ???
??
??
98?8?25?
79
???????????
????
A?
B?
VSAT ??
?????
?????
?????
????
?????
?????
?????
?????
?????
?? ???
?? ???
??
??
98?8?25?
80
????????
????
????
A?
????
?????
?????
?????
?????
?? ???
?? ???
??
??
98?8?25?
81
?????????????(?)
??? ??? MODEM
T1 ??? T-coder
????? Echo Canceller
??? Up Converter
?? ??? RF Amplifier
????? Echo Canceller
????? Echo Canceller
T1 ??? T-coder
??? ??? MODEM
??? Down Converter
??? ??? Low Noise Amplifier
??
????? Echo Canceller
????
????
????
98?8?25?
82
VSAT??
  • ???????
  • ??????????? (?????2.4???)
  • ?????(1W,2W...)
  • ??????????????
  • ?????????????????
  • ????
  • ????(Star Network)
  • ???(Point to Point)
  • ????(Mesh Network)

98?8?25?
83
????(TDM/TDMA)
Remote
Remote
Remote
Remote
? ? ? HUB
98?8?25?
84
????(Mesh)
Remote
Remote
Remote
Remote
Remote
Remote
? ? ? HUB
98?8?25?
85
?????
? ? ? Remote site
? ? ? HUB
1.8?
????
4.57?
????
????
Outdoor Unit
????
??????
??????
??????
Indoor Unit
????
? ? ?
????
????
98?8?25?
86
????
  • ?????????
  • ????/????
  • ????/??????
  • ????????
  • ??????
  • ??/????????
  • ?????????
  • ???????????????????

98?8?25?
87
Internet/Intranet ???
Enterprise Server
? ? ? HUB
Indoor Unit
Client A
Modem
Modem
TX only
RX only
Client B
Enterprise Server
Internet/Intranet Host
98?8?25?
88
?????? ( DirecPC )
???????? ( Turbo Internet ) ? ??
?????? ???????? ??TCP/IP??
??????????? ??? ?????? ?????
????? ????? ??????? ??????
98?8?25?
89
???????? ( Turbo Internet )
Uplink
Broadcast
98?8?25?
90
??????? (Multimedia Services)
? ?? ??1.5Mbps?? ??MPEG1?AVI
?RealPlayer???? ????(Broadcast)???(Multicas
t)?? ????(Real-Time)???? ???
????????????? ???????????? ??????

98?8?25?
91
??????? ( Multimedia Services )
Uplink
Broadcast
( Real Time Audio Video )
98?8?25?
92
?????? ( Package Delivery Services )
? ?? ????????(??????) ,???????
??????3Mbps ,?????????100? ??????????
???????? ?????? ???
?????? ????? ????
?????(one-to-many)???? ????DES??????
98?8?25?
93
?????? ( Package Delivery Services )
Uplink
Broadcast
( Data )
98?8?25?
94
??????????
???
???
????/????
95
??????
98?8?25?
96
???????????
????
???
??????
Power Amplifier
Low Noise Amplifier
Power Amplifier
Low Noise Amplifier
Up Converter
Down Converter
Up Converter
Down Converter
MODEM
MODEM
??
Encoder
Encoder/Decoder
??
??
98?8?25?
97
?????? (SNG)
???
98?8?25?
98
????????
  • ??????880????
  • ????/-0.050
  • ????EUROSTAR 2000????
  • ????12?(??13?)
  • ???????(Ariane)????
  • ??C??14?36 MHz???
  • Ku??16?54 MHz????
  • ????????
  • C??-??6.4256.725 GHz??3.4003.700GHz?
  • Ku??-??14.0014.25 GHz(K1K2)
  • ??11.4511.710 GHz?
  • ??14.2514.50 GHz(K1)
  • ??12.5012.75 GHz?
  • ?????????
  • C??-SFD-72-92 dBW/m2PA67W TWTA?
  • ????????????????????????????????????
  • Ku??-SFD-75-95dBW/m2
  • PAK1_90W TWTA
  • ????????????????????????????????

98?8?25?
99
????
  1. ???????????????,?????????????????????????????,????
    ??,?????????????????
  2. ?????????????????,???????Terrestrial
    networks???????,??????????????,???????
  3. ?????????,???????????,??????????????
  4. NCC????????,?????????????????????????,????????????
    ?????????????

98?8?25?
100
Thank You !
jfhuang_at_mail.ntust.edu.tw
98?8?25?
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