Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

What does the far field mean for a transmitter?

Status
Not open for further replies.

roustabout

Member level 2
Joined
Jun 30, 2004
Messages
48
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
317
far field

Wat does the far field meant for a transmitter?
 

Re: far field

the far field means the power distributed pattern in the space is not change with the distance from the transmitter,the only change is the amplitude,it not the same as the near filed that its power distributed pattern is changed with the distance from the transmittter!
it is important of the far field to the transmitter,because it determine how the power of the transmitter is distributed in the space,it determine the efficieny of the transmitter's power for the desired traget you want to communicate with
 

far field

Generally all "transducers" antennas, electrical, but sonic also, generate a pattern that change its parameters along the transmission axis.
This change is smooth but for classification, has been creeted almost 2 zone: the near fiels (also called Fresnel Region) and the Far field (also called Fraunhofer region). Generally the far field boundry is 2D^2/lamda (D=dish diameter).
In far field, the wave is assumed as "plane" (i.e. not spheric) and the beam is pencil shaped.
On the near field the wave plane is curved, quasi spheric, and the beam is quasi cilindrical.
Of couse to do businnes with radio signals, antennas are on the far field.
 

Re: far field

At far field, you can assume that your waveform is a plane wave.

T Zul
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top