ADAR1000-EVAL Measurement result

Could anyone clarify and give me any advice?

Part : ADAR1000-EVALZ

We tested the method provided by the user guide.
Test was conducted using ADAR1000 Max Gain Settings provided by ADI web.
Based of Freq. = 9.5GHz @Tx1, the gain was 15.9dB. The board loss was 3.2dB.
The datasheet says 21dB.
can you advise me

Please kindly help.
Please. Can someone tell me?

  • 0
    •  Analog Employees 
    on Jul 20, 2021 4:09 PM

    Can you confirm the bias registers below have the following data values?

    Reg 0x36, Data = 0x2D
    Reg 0x37, Data = 0x06

    The gain can vary quite a bit over bias values.  For example, the gain decreases by about 5 dB between nominal and low bias settings.

  • 0
    •  Analog Employees 
    on Jul 27, 2021 4:20 PM

    Have you had a chance to remeasure the Tx gain with the bias values outlined in my last response?

  • I tested according to your advice.
    However, the same result was obtained.

    The file you advised and the file provided by ADI Web was the same.

    If we change the Bias Current, MaxGain is similarly measured.
    However, with the Bias Current change, the current increased significantly.
    Transmit Mode: 410mA
    Receive Mode: 330mA

    Is it okay to use it this way?

    And, how can I check the TEMPERATURE SENSOR?

  • +1
    •  Analog Employees 
    on Jul 30, 2021 4:17 PM in reply to Lee Jaegook

    The lower gain could be explained by part-to-part variation and/or board-to-board variation. 

    It is OK to use the part with higher bias settings, but know that the RF metrics will change as well, which we didn't characterize.  We only tested at nominal and low bias settings. 

    Here is a simple Sequence to read the Temperature Sensor value:

    • Write 0x60, to Register 0x32 
      • Enables ADC, 1MHz clock, temp sensor input
    • Write 0x70, to Register 0x32   
      • Initiates conversion cycle 
    • Read ADC_EOC bit from Register 0x32
      • Low during conversion cycle. High when complete.
    • Read Reg0x033 
      • This is the ADC output
  • We are testing with two EVAL boards.
    Both board of our symptoms are the same.

    There is a table for Power Modes in Datasheet page26.
    Even using this method, different values from the datasheet were measured.
    Is it the correct way to use the Bias Current value to match the same measurement value as the datasheet?
    Please tell us in detail what it means to change the Bias Current Value.

    And,
    When measuring NF (TX1 measurement standard), if only Tx1 is ON, it is similar to the datasheet, but if TX2 is ON and TX1 is measured, a 2dB difference occurs. (TX2 Term state)
    In this way, when TX3 and TX4 are turned on, NF gradually increases.
    This is quite strange. Is this correct?