AAAS Flashcards
an electronic device which produces radio waves with an antenna
Transimtter
is for transmission of music and speech
radio- telephony transmitter
transmission of signals
radio- telegraphy transmitter
transmission of moving pictures
TV transmitter
Is the transmission of codes.
is an electronic device that receives radio waves and converts the information carried
by them to a usable form
Code Transmitter
may be defined as its ability to drive the output transducer to an
acceptable level
Receiver’s sensitivity
may be defined as the extent to which a receiver of
differentiating between the desired signal and disturbances at other frequency
Receiver’s Selectivity
is the way radio signals are transmitted from one point to another inside the earth’s atmosphere or free space
radio propagation
is a radio wave that travels along Earth’s Surface
Ground Wave
Used for long distance transmission. It has the ability to strike the ionosphere, be refracted from
it to ground, strike the ground, be reflected back toward the ionosphere..
Sky wave
The propagated wave is direct from transmitting to receiving antenna and does not travel along
the ground. And it is also called line-of-sight transmission disturbances.
Space Wave
A communication satellite is placed into synchronous orbit, which means its position remains
fixed with respect to the earth’s rotation
Satellite Communication
VLF
Under water comms
LF
30,000 hz- 300,000hz AM radio
MF
300,000- 3MHz AM radio
HF
3M-30M Hz - AM radio Long distance Aviation Communication
VHF
30M-300M Hz - FM
UHF
300M to 1B Hz - Fm, Tv, phone, wireless network, blue tooth gps