• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 30 subscribers
  • Views 283 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

IWR1642: RF Specifications

Akshay Patel1
Intellectual 690 points
Part Number: IWR1642

Hi,

1) What is TX-RX isolation in IWR1642?

2) What is maximum allowable input power at RX port of IWR1642?

3) 1-dB compression point is specified in section 5.7 in datasheet. It is specified at which point, LNA, Mixer or ADC.

Thanks,

Akshay

  • 0
    TI__Mastermind 25795 points

    Akshay,

        1) On chip Isolation between TX to RX is better than 40dB.

        2) Allowable input power is function of Receiver gain, Please see below trade-off between Gain, P1 dB and Noise figure. 

        3) 1-dB compression point is specified in section 5.7 in datasheet is for LNA input.

    Thanks and regards,

    CHETHAN KUMAR Y.B.

  • 0 in reply to CHETHAN KUMAR Y.B.
    Intellectual 690 points

    Hi Chethan,

    Thanks for quick reply. I have few question for clarification.

    1-dB compression point specified for LNA input is -8 dBm. In graph P1dB range is ~ -23 dBm to -47 dBm. P1dB in graph is at LNA or mixer?

    What happens if higher amount of power, say 0 dBm, is received at RX port. Does it damages IC or there is protection so that only clipping will occur and no damage?

    Thanks,

    Akshay

  • 0 in reply to Akshay Patel1
    TI__Mastermind 25795 points

    Akshay,

         There are two compression points in the receiver chain: 

    1) Out of band compression point, Typically this would be applicable to compressing the LNA; TX to Rx (Antenna Isolation would dictate this parameter) -8 dBm parameter would refer to this spec. We have High pass filters which provides additional attenuation for this TX-RX leakage signal. 

    2) In band compression this is after the mixer going into Base-band chain (In band signals are the one after the high pass filter pole frequency), Typically this is the function of receiver gain. There is a trade-off between receiver gain, In band 1dB compression point and Noise figure as shown in the above graph. Typically this is set at a pint where you get maximum benefit of NF without significantly degrading in band 1dB compression point. 

    Thanks and regards,

    CHETHAN KUMAR Y.B.

  • 0 in reply to CHETHAN KUMAR Y.B.
    Intellectual 690 points

    Hi Chethan,

    I got answer to first question. Second question is missed.

    What happens if higher amount of power, say 0 dBm, is received at RX port. Does it damages IC or there is protection so that only clipping will occur and no damage?

    According to graph if I select RX gain = 48, then P1dB after high pass filter is -47dBm. So acceptable input at LNA will be -47dbm - 48 = -95dBm, which is very small amount. For object at smaller distance, input power will exceed this level in most cases. Is this understanding correct? Correct me if I am wrong.

    I am asking these questions as we need to find suitable antenna parameters for detecting objects b/w 0 to 60m with high precision.

    Thanks and Regards,

    Akshay

  • 0 in reply to Akshay Patel1
    TI__Mastermind 25795 points

    Akshay,

        Device damage will not occur at 0 dBm power, Absolute max power within the safe operation for the receiver is 10dBm. 

    Yes, your understanding is correct. For object at smaller distance, input power will exceed this level in most cases, However care need to be taken, there would other objects such as walls, grounds, and other clutters would be reflecting large power might compress the receiver for large receiver gain settings. 

    For small gains gain setting reflected input power may not exceed detection threshold limits, Hence right balance need to be arrived. 

    Thanks and regards,

    CHETHAN KUMAR Y.B.