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AD9371 Questions 3

Question asked by Shay.L on Feb 20, 2017
Latest reply on Mar 29, 2018 by Vinod


I am working at 3.5GHz, LTE signal, 10 - 20MHz signal BW.

I have few questions about the AD9371 Rx path:

1. According to the data sheet the Maximum Recommended Input Power to the Rx path is -14dBm
    At Min Rx attenuation the measured max gain of the Rx path is 16.45dB.
    The input power to the ADC is -14dBm + 16.45dB = +2.45dBm
    The Rx ADC full-scale voltage is +0.707Vp, the Max Pin ADC [dBm] is +6.988dBm, I believe this is the ADC saturation       point.
    It seems that I can increase the max input power by 4.53dB (+6.988dBm - 2.45dBm = 4.53dB) to -9.47dBm  
    (-14dBm + 4.53dB = -9.47dBm) and this can be my Max input power to the Rx path.
    Am I correct ? Can I assume that the Max power to the Rx path is -9.47dBm and keep the proper back off from
number ? Or I should keep the -14dBm as Max power to the Rx path and if so what back off I should keep ?

2.  Receiver blocking  -  According to  ETSI EN 302 774 V1.2.0 (2011-10) page 12 I should keep Minimum offset of the
     interfering signal from the channel edge = 2.5 * Signal BW, the level of the interfering signal = -15dBm and the wanted          signal mean power should be PSENS + 6 dB.
     I plan to set the AD9371 Rx gain at 10dB and to use about 28dB external LNA gain in order to reduce the N.F of the
     AD9371 Rx path. 
     How can the AD9371 Rx path work with this high power interfering signal and keep the wanted signal mean      
     power at PSENS + 6 dB ?

3.  I didn't see a Tx or Rx 10MHz BW signal profile in the AD9371 TES.
     Can the AD9371 work with a 10MHz BW Tx or Rx signals ?