Home » TVRO Introduction » TVRO Antenna Intr...

TVRO Antenna Introduction and Application

Posted by admin on almost 7 years ago.

Antenna feed system can ensure high enough gain and the lowest possible antenna noise. And it can effectively feedback faint radio wave to low noise amplifier with high-frequency. Moreover, it shall provide correct antenna pointing and polarization mode. Besides, antenna system shall possess high enough capacity of bearing wind pressure.

Antenna type

Antenna is divided into two categories which are rotated polarization and non-rotated polarization. Rotated polarization antenna has two types which are spiral and parabolic. And parabolic antenna has two basic forms. One is prime focus parabolic antenna of feed forward with only one reflector. The other is Cassegrain antenna of feed back, which processes main reflector (paraboloid) as well as sub-reflector (hyperboloid). And for Cassegrain antenna, radio wave converges after reflecting twice. Primary focus antenna is simple but its performance is worse. Low noise preamplifier of Cassegrain antenna can be placed at the back of paraboloid so as to prevent from sunlight. Cassegrain antenna is especially suitable for satellite TV station in the tropics; however, the cost is higher.

  Besides, there are flat panel antenna and ring focus antenna. The former is portable, suitable for family receiving. The latter decreases antenna sidelobe and improves receiving efficiency. To flexibly receive TV program on different satellites, power-driven polar axis antenna is produced. This type of antenna possesses the original antenna, feed; moreover, it also possesses electric motor speed-reduction drive antenna mechanism and antenna controller controlled by microcomputer.

  Some cable television system adopts multi-focus parabolic antenna, which uses fixed antenna to receive more satellite’s television signal simultaneously. This type of antenna has more feeds which receive signal from different satellites to form more beams. And its reflector uses deformed sphere and paraboloid. For example, the reflector consists of rectangle cut out from sphere or two kinds of curves. And its horizontal direction is circular arc while vertical direction is a part of paraboloid.

  The diameter of parabolic antenna of large satellite communication station is 15~30m, the medium one is 4~10m. Ku-band receiving antenna of household live satellite TV can be as small as 0.5m. Now C-band satellite TV receiving station mostly uses 1.5~3m antenna while Ku-band uses 0.75~1.5m antenna. With the improvement of efficiency and performance of antenna, feed, and reduction of low-noise amplifier’s temperature, the antenna diameter can be reduced.

Earth Station Antenna   1.2m tvro antenna   1.8m tvro antenna   2.2m tvro antenna   3m tvro antenna   3.7m tvro antenna   4.5m tvro antenna   6.2m tvro antenna   7.3m tvro antenna   9m tvro antenna   16m tvro antenna