Quantcast Truncated Paraboloid

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
3-18 If a dipole is used as the source of radiation, there will be radiation from the antenna into space (dotted lines in figure 3-17) as well as toward the reflector. Energy that is not directed toward the paraboloid has a wide-beam characteristic that would destroy the narrow pattern from the parabolic reflector. This occurrence is prevented by the use of a hemispherical shield (not shown) that directs most radiation toward the parabolic surface. By this means, direct radiation is eliminated, the beam is made sharper, and power is concentrated in the beam. Without the shield, some of the radiated field would leave the radiator directly. Since it would not be reflected, it would not become a part of the main beam and thus could serve no useful purpose. The same end can be accomplished through the use of a PARASITIC array, which directs the radiated field back to the reflector, or through the use of a feed horn pointed at the paraboloid. The radiation pattern of a parabola contains a major lobe, which is directed along the axis of revolution, and several minor lobes, as shown in figure 3-18. Very narrow beams are possible with this type of reflector. View A of figure 3-19 illustrates the parabolic reflector. Figure 3-18.—Parabolic radiation pattern. Truncated Paraboloid View B of figure 3-19 shows a horizontally truncated paraboloid. Since the reflector is parabolic in the horizontal plane, the energy is focused into a narrow horizontal beam. With the reflector truncated, or cut, so that it is shortened vertically, the beam spreads out vertically instead of being focused. Since the beam is wide vertically, it will detect aircraft at different altitudes without changing the tilt of the antenna. It also works well for surface search radars to overcome the pitch and roll of the ship.


Electrical News
EEVblog #645 – TRS-80 Model I Retro Computer Teardown
Dave looks inside the most popular microcomputer of the 1970′s,...
eevblog.com
Wearables Sing in Smart Clothes
The future of mainstream wearable technology may be driven by...
eetimes.com
ST Opens MEMS Microphone Test Laboratory
STMicroelectronics NV has set up an anechoic chamber in Taipei,...
eetimes.com
7 Insurance Issues With Your Self-Driving Car
People talk about the significant reduction in automotive insurance rates...
eetimes.com
Microsemi Bolsters FPGA Stance With Mingoa Acquisition
The Mingoa deal demonstrates Microsemi's push to gain market share...
eetimes.com
FAA Rules on Drones vs. Model Aircraft Contested
Proposed FAA dividing line between model aircraft and drones is...
eetimes.com
Think Different, Innovate by Reuse
It's time we slow down the fevered pace of new...
eetimes.com
Space Business Rising, Experts Say
The emerging commercial space sector is making progress but still...
eetimes.com
Connecting Islands of Industrial IoT
The Industrial Internet of Things often starts with a wealth...
eetimes.com
Graphene / Lithium Ion Capacitor Kickstarter BS
I’ve had a lot of people ask me to comment...
eevblog.com
Six Hour Workday? Sign Me Up!
The economists got it wrong when they though productivity gains...
eetimes.com
Geotracker Tags Unlicensed Band
We're tracking a startup budding from San Francisco's Internet of...
eetimes.com
Teardown.com: Amazon Brings Fire to Phone Market
Qualcomm is the primary provider of the key integrated circuits...
eetimes.com
What's That Smell? An App for That Soon, Says Sensirion
With the acquisition of neighbouring cloud business Koubachi AG, Zurich-based...
eetimes.com
Samsung's Silicon Valley Home
Samsung is building a 10-story complex in the heart of...
eetimes.com
Sony Invests in Stacked Image Sensor Manufacturing Capacity
Sony Corp. has said it plans to invest 35 billion...
eetimes.com
Life After 28nm: Think Network-on-Chip
As Moore's Law reverses beyond 28nm, consider network-on-chip (NoC). While...
eetimes.com
NASA Exec Says, 'Boldly Go!'
Pete Worden, director of NASA's Ames Research Center, challenged a...
eetimes.com
Friday Quiz: Decibels and S Parameters
Test your knowledge of that ratio of two powers and...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +