Transcript Slide 1

Everything your parents never
told you about antennas
Johan Führi
Design Engineer
Poynting Antennas, South Africa
MUM, Poland 2008
Poynting Antennas
Antenna and enclosure design and manufacture
Company size 180 people, 2600m2 factory
20 R&D staff (3xPh.D, M.Sc’s, B.Sc’s, Techs)
Turnover USD 7.5 million p/a.
About 40,000 units per month output.
Export to Europe, Australia, Malaysia, Singapore,
Israel and United States.
 Various low cost, high performance fabrication
technologies developed in-house.
 Cutting edge outdoor enclosure portfolio with
proven applications globally.
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Overview
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What is an antenna?
How does it work?
What antennas cannot do
Antennas in practice
New technologies in antenna/enclosure
systems
What is an Antenna?
 “The wireless telegraph is not difficult to
understand. The ordinary telegraph is like a
very long cat. You pull the tail in New York
and it meows in Los Angeles. The wireless
is the same, only without the cat.” – Albert
Einstein.
 Mechanical device that converts an
electrical signal into an electromagnetic
wave and vice-versa
 It is not an AERIAL
How does antennas work?
 Antenna focuses outgoing and incoming signals
 In a particular direction
 With a particular pattern
 More ‘gain’ = more focusing in the firing direction
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In TX, less signal sent in other directions
In RX, antenna is ‘deafer’ in other directions
More signal in the firing direction
Lower interference
 More signal = higher range/data rates
How does antennas work?
 More gain = larger size
 Panel/dish antennas – gain proportional to area
300cm2
75cm2
8 dBi
 Limited by physics
 Size/gain trade-off
 Must keep losses down
14 dBi
20
dBi 2
1200cm
What antennas cannot do
 Antenna ‘bandwidth’
 Can’t work over arbitrarily wide number of channels
 Frequency limited
http://www.trevormarshall.com/waveguides.htm
100-119
120-139
140-159
160-179
180-199
How does antennas work?
 In summary
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Antennas focus energy to increase signal
High gain means less signal in other directions
Gain depends on antenna size
Cannot cheat physics – must reduce loss
Antennas can work differently in different
channels
Antennas in practice
 Connecting to the Electronics
 Choosing the right antenna
 Distribution
 High site
 CPE
 Point-to-Point
 Indoor
Connecting to the Electronics
 Keep the radio close to the antenna
 RF cable kept short
 Negligible losses – best possible signal
 Lower susceptibility to lightning impulse
Mounting Electronics Outdoor
Weatherproof enclosure
UV stabilised, shielded ethernet cable
Integrated panel antenna
Infrastructure location
Wireless card
Routerboard platform
POE Injector
Wired network Mains AC
Choosing the right antenna
 Omni-directional antennas – The Ultimate Solution?
Choosing the right antenna
 Sector Antennas
 Cover only the areas that you need to cover
 Multiple sector antennas per enclosure
 One antenna per radio
Choosing the right antenna
 Client Premises Equipment – CPE
 What is important?
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Easy installation
Aesthetics
Good performance
Low cost
iPoynt
240mm
55mm
Compact aesthetic design
IP67 rated, injection-moulded design
Ethernet disconnect cable gland
230mm
iPoynt
Wireless electronics
Integrated directional antenna
IP67 watertight
14dBi
@ 2.3-2.7seal
GHz (x4.0 range*)
Ethernet
clip-off gland
17dBi
@ 3.3-3.8
GHz (x5.6 range*)
20dBi @ 5.1-6.0 GHz (x8.0 range*)
* Range relative to 2dBi dipole antenna
iPoynt
Flexible electronics mounting
Grounding lug built into
mounting structure
Pigtail Ethernet disconnect
gland
RB133C/RB411 ready!
Window knock-out
N-connector knock-outs
iPoynt
Separate Elevation adjust
Pole or wall mounting flange
Separate Azimuth adjust
Choosing the right antenna
 Point-to-Point
 High gain dish/panels with heavy duty enclosures (long
range)
 Fully integrated medium gain solution (medium range)
Choosing the right antenna
 High gain antennas
 Narrow beamwidth
 Cutting out noise
 High gain
 Improved signal strength
 Higher data rates
 Grid Antennas
 Lower wind resistance
Choosing the right antenna
 Indoor Antennas
Main problem is Multipath Interference
Space diversity
Polarisation diversity
Relatively low gain antenna – wide
beamwidth
 Going through walls – unreliable signal
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Choosing the right antenna - Diversity
WLAN-A0030
WLAN-A0032
Integrated quad diversity (spatial &
pol) 2.4 GHz 8dBi Patch antennas
Dual integrated 2.4 GHz 14dBi
Panel antennas
‘Indoor MIMO AP Enclosure’
‘Indoor AP Enclosure’
‘Outdoor diversity/2 channel link’
WLAN-A0031
Integrated diversity 2.4 GHz 7dBi
Omni’s
‘Outdoor AP Enclosure’
WLAN-A0033
Dual diversity 2.4 GHz 8dBi Omni’s
Integrated 5GHz 20dBi panel
‘Local Access Node’
To the future
 High performance antenna technology
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Optimisation-based design
Wide band
Low loss
Low sidelobes
To the future
 Integrated Multi-sector enclosures
 Compact integrated outdoor enclosure for 5GHz
 Quad-reconfiguarable sector array
 4x 90 degrees
 2x180 degrees
 1x360 degrees
4x 90 degrees
2x 180 degrees
1x 360 degrees
To the future
 Antenna sharing for Nstreme 2
 Only one pair of antennas to run Nstreme 2
 Minimise installation costs and mounting space
 Need wideband antenna, diplexer
HI Band
LO Band
HI Freq
RX Radio
TX Radio
Diplexer
Routerboard
LO Freq
RX Radio
HI Freq
Diplexer
Routerboard
TX Radio
LO Freq
To the future
 Dual polarised antenna enclosure
 Two antennas in one enclosure, HP and VP
 Single Nstreme 2 enclosure
Thank you