Satellite Dish Antenna Questions and Answers for Viva

Answer-1: A satellite dish is a dish-shaped type of parabolic antenna designed to receive microwaves from communications satellites, which transmit data transmissions or broadcasts, such as satellite television.

Answer-2: The parabolic shape of a dish reflects the signal to the dish?s focal point. Mounted on brackets at the dish's focal point is a device called a feed horn. This feed horn is essentially the front-end of a waveguide that gathers the signals at or near the focal point and 'conducts' them to a low-noise block down converter or LNB. The LNB converts the signals from electromagnetic or radio waves to electrical signals and shifts the signals from the down linked C-band and/or Ku-band to the L-band range. Direct broadcast satellite dishes use an LNBF, which integrates the feed horn with the LNB.

Answer-3: A dish antenna, also known simply as a dish, is common in microwave systems. This type of antenna can be used for satellite communication and broadcast reception, space communications, radio astronomy, and radar.

Answer-4: For satellite television reception, coaxial cable is used.

Answer-5: A parabolic antenna is an antenna that uses a parabolic reflector, a surface with the cross-sectional shape of a parabola, to direct the radio waves. The most common form is shaped like a dish and is popularly called a dish antenna or parabolic dish.

Answer-6: The main advantage of a parabolic antenna is that it is highly directive; it functions analogously to a searchlight or flashlight reflector to direct the radio waves in a narrow beam, or receive radio waves from one particular direction only.

Answer-7: Cylindrical, Paraboloidal or dish, Axial or front feed, Offset or off-axis feed, Cassegrain.

Answer-8: The directive qualities of an antenna are measured by a dimensionless parameter called its gain, which is the ratio of the power received by the antenna from a source along its beam axis to the power received by a hypothetical isotropic antenna.

Answer-9: The angular width of the beam radiated by high-gain antennas is measured by the half-power beam width (HPBW), which is the angular separation between the points on the antenna radiation pattern at which the power drops to one-half (-3 dB) its maximum value.

Answer-10: A set-top box (STB) or set-top unit (STU) is a device that connects to a television and an external source of signal, turning the signal into content which is then displayed on the television or other display device.