What sort of signal travels from uplink dish to satellite?

Question

is it in Hot air form or any other form..then how it travels in vaccuum n strikes satellite?

Answer 1

Microwave signals if its a parabolic dish.. else laser can also be used

Answer 2

these r nothing but em waves these waves can tavel in space in vacum any where thi rang of frequency is 8 ghz for uplink frequency  and 12 ghz for downlink frequency

Answer 3

Electromagnetic (EM) waves.

EM waves that humans use, have wavelengths from thousands of meters to trillionths of a meter. Radio type EM waves for propagation are supported by vacuum, air or dielectric media like plastic or Teflon. For satellite links we use radio waves known as 'microwaves'.

Engineering practice have divided Microwaves into bands - L, S, C, X, Ku, K, Ka and submillimeter waves. L, S, C bands cover in a ratio of 1:2 (called octave),1 to 2, 2 to 4, 4 to 8 Gigahehertz frequency bands respectively. A Giga Hertz (GHz) is 1,000,000,000 cycles per second and is named after 'Hertz', the German Engineer who wasthe first to radiate EM waves. Product of frequency and wavelength is 300,000,000 m/sec that is the 'speed of light'. Hence, higher the frequency, proportionately lower is the wavelength. Higher bands have ratios of 2:3.

Uplink frequencies to satellite have been fixed in C band and down-link in almost X band. Nowadays Ku is being used. If frequency (carrier) is higher consequently the bandwidth (nominally a tenth) is larger so we can accomodate more channels of data, video (TV that requires 4.5 MHz) and audio (speech that requires about 8kHz).

Another factor is design of Antenna, the end-device in a radio system transmitting or receiving EM waves beaming around, in air or space. Transmission of all power that is efficiently (with as little losses as possible) converted to EM energy. It should be beamed efficiently at the invisible speck that is the geo-stationary satellite, by 'quarter wave (1/4 of wavelength) dipole' that illuminates a large parabolic dish that directs a pencil like beam. Unlike a ground based antenna, satellite antenna due to constraints of available space, size and power, is smaller; hence the use of higher frequency band.

Answer 4

Microwave

Answer 5

It is not air. They are electromagnetic waves.To be specific the are radio waves. Electromagnetic waves can travel in vacuum.Actually the light visible to us are also electromagnetic waves. But radio waves cannot be seen like visible light.