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.

Distance to source for impinging waves planar

Status
Not open for further replies.

Circuit_seller

Full Member level 5
Joined
Sep 23, 2002
Messages
300
Helped
17
Reputation
34
Reaction score
7
Trophy points
1,298
Activity points
2,350
Planar Wave

Hi

What shuould be distance(in landa) of a source to an receiver antenna, to become impinging waves planar?
 

Re: Planar Wave

hello,

isn't this the same as the far field condition used in e.g. antenna measurements?

best regards
 

Re: Planar Wave

for far field condition:

L ≈ 2D²/λ

L is the measure distance , D is the antenna dimension

λ is the wavelength .
 

Re: Planar Wave

Hi

Length of antenna(monopole) is 1 meter and wavelength is 2 meter, so according to your formula L is less than 1 meter.
I think it is wrong.:D
 

Re: Planar Wave

this depends on the size of receiver.
 

Re: Planar Wave

Hi

What do you mean by size of receiver?
 

Re: Planar Wave

the formula could be found in electromagnetic book ,

I think it mentions that if L is large enough , and it could be

identified a far field.

L >> 2D²/λ
 

Re: Planar Wave

Well, you can not achieve a real plane wave. But you can create an approximation to it. What you need is an electromagnetic wave whoose amplitude and phase does not vary over a certain area. So the distance required to obtain such an approximation does depend on the size of the antenna or the aperture of the antenna.
 

Re: Planar Wave

Thanks irfan1

Suppose i have a 1m monopole antenna on top of a car, transmitter frequency is 140MHz and the eviroment is reflection free, what should be the distance from transmitter to receiver?

thnks in advance.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top