Why we need build out door antenna measurement

[noisepic]

Most of the antenna we can measure its characteristic in chamber, near field system.
I wonder why some company build this kind of system? and what types of antenna must be test by this system.

 

[kspalla]

Near field system extrapolate far filed response with some calibration Inverse FFT etc.
if this calibration has error then the far filed response which is practical will have wrong design outcomes on gain beam width, etc.

 

[flanello]

What about the price?
Is an outdoor measurement setup less expensive than a big chamber with a near field measurement?
And perhaps the outdoor measurement is more accurate, maybe you can find some numbers....

 

[kspalla]

OUTDOOR MEASUREMENTS ARE more EXPENSIVE and error pron due to field dynamics like building constrictions, flights ,road traffic near by etc.