aaron_do wrote on Apr 7^th, 2008, 5:31am:

It depends on required input dynamic range and calibration's accuracy. For example, use compensation table determined by calibration procedure.

If you adopt complicated calibration over temperature, supply voltage and input frequency,
accuracy of less than +/-1.5dB is very possible.
Here you need temperature sensor, ADC and EEPROM, etc.

Hi,

thanks for the replies. I took pancho_hideboo's reply to mean automatic calibration during operation. Are you, Jerry, talking about calibration of the chip itself (for instance trimming of resistors)? Also, why would you need such accuracy in the RSSI? I understand you may want to limit the amount of power transmitted to and from the cell phone, but to whay accuracy?

thanks,
Aaron

Hi,
I think that it depends on the system, I don't think that it's needed the same accuracy in a Bluetooth like system(where you use RSSI for power saving) than in a mobile phone system(that control cell handover or cell breathing in the UMTS system).
Hope it helps,

adjustment values are a stored numeric, dumped into flash in a cell phone, not used to trim the chip. Essentially adjustments done in Software (32dbm out is setting 11111 on one phone and 11110 on another kind of thinking)

All phones (CDMA and GSM) need to adjust power output, thats inherent to the system needs.
Accuracy required is within 1-2 db if I remember correctly.

jerry