Antenna problem,please give me a hand!Thanks a lot!

Hi,guys!
How much the VSWR of the antenna with the frenquency in 850MHZ to 1900MHZ?
why do the 3G basestation transreciver's antenna have a exact VSWR?




Thank you!

VSWR depends on several things. Its not possible to tell by just knowing it operates between 850MHZ to 1900MHZ. It depends on its type, how it resonates with frequency and its input impedance matching.

Is never an exact VSWR specification. Always should be better or equal than the specified one.

Higher VSWR is translated directly in a mismatch loss, which means losing RF output power. The RF power lost is translated in thermal dissipation.

A good rule to follow, generally low and medium power amplifiers needs better than 2:1 VSWR at the output, when high power amplifiers needs better than 1.5:1 VSWR at the output.

For clarification:
The smaller the VSWR the better.