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
Your Part in the Recovery
Engineers and innovators are central to the slow but ongoing...
eetimes.com
Motor Controllers Offer Improved Noise Immunity
Operating at 5V gives these digital signal controllers enhanced noise...
eetimes.com
NXP to Pick Up Its Missing IoT Link - Bluetooth Low Energy
In pursuit of the Internet of Things market, NXP Semiconductors...
eetimes.com
USB Oscilloscopes Get Beta Drivers for Open-Source Hardware
Pico Technology has released beta versions of drivers for BeagleBoneBlack...
eetimes.com
It's Alive! The 3D Printing of Living Tissues
Within a generation, we likely will not just hear of...
eetimes.com
Curiosity Killed the Cat (Just Call Me Mr. Curiosity)
Max desperately needs a cat deterrent, but how should this...
eetimes.com
Memory Design Articles: Diagnostics, Datacenters & Failures
Here's a roundup of recent design articles that are relevant...
eetimes.com
Megachips to Launch DSP-Based Sensor Fusion IC
The growing sensor-fusion controller market for smartphones and wearable devices...
eetimes.com
MediaTek Plans $49 Million Investment in China's Chip Fund
Taiwan's largest chip designer has announced it will invest $48.9...
eetimes.com
Reduce Noise When Making M-PHY Measurements
To make useful measurements on M-PHY Gear 3, you need...
eetimes.com
EEVblog #686 – Mailbag
A monster sized high definition 50fps Mailbag, with two special...
eevblog.com
Startup to Open Source Parallel CPU
Rex Computing plans a parallel processor that could deliver a...
eetimes.com
OCZ Cuts Into Read-Intensive SSD Segment
The SATA-based Saber 1000 Series is yet another option in...
eetimes.com
Infotainment Systems Drive Automotive SSD Adoption
In-vehicle entertainment and navigation systems are becoming more mainstream and...
eetimes.com
Scaling Up Text Rendering on Scaled-Down Devices
The need to support a widening range of languages and...
eetimes.com
What Is Design-to-Cost & Why Does It Matter?
Design-to-Cost should be part of your design process. With a...
eetimes.com
Can Japan Get Her Groove Back With IoT?
Japan once looked like a world leader in smart home...
eetimes.com
The 10 Commandments of Electronics
Although these 'commandments' are presented in a humorous manner, they...
eetimes.com
Broadband Demand Hits the High Seas
Cruise ship operators Royal Caribbean and Carnival are exploring new...
eetimes.com
Anritsu ShockLine VNAs Receive Frost & Sullivan Award
Its line of "faceless" VNA used for production RF T&M...
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 +