Introduction to radar antenna

The antenna is the part of the radar that connects with the outside world . It serves a variety of purposes ：
(1) Concentrate energy during launch , It has directivity and narrow beam width ;
(2) Collect echo energy from the target ;
(3) Provide target angular position measurement ;
(4) Provide angular resolution ( Or separation ) Spatial resolution of the target ;
(5) Observe the desired airspace .
The antenna can be a mechanically scanned parabolic reflector 、 Mechanically scanned planar phased or mechanically scanned end fire antenna . It can be a phased array of electrical scanning , The power of a single transmitter is distributed to each array element using a feed configured with branch feeders or empty feeders , Or electric scanning phased array , Each of its array elements adopts a solid state “ pocket ” radar ( Also called active aperture phased array ). Each antenna has its own special advantages and limitations . generally speaking , The bigger the antenna, the better , But there are practical limits to its size .
notes ： The article is excerpted from 《 Radar manual 》 The third edition