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 Aug 3, 2021 4:29 PM in reply to Lee Jaegook

    The low gain cause must be something common to how you are setting up the part. 

    The bias levels that I already gave should provide gain values that are close to the datasheet (minus the insertion loss of the lines).

    The various bias current values controls the current in the several subcircuits (vector modulator, VGA, LNA, Driver).

    The NF is measured with just the measured channel enabled.  So if you are measuring Tx1, only enable Tx1 to get a NF close to datasheet specification. 

  • Hi, jdobler

    I checked the data of the S2P file provided by ADI Web.
    This data is worse than the values in the Datasheet.

    Is this correct?

    And,

    How is the switching time measured?

  • +1
    •  Analog Employees 
    on Aug 9, 2021 3:40 PM in reply to Lee Jaegook

    The Tx S2P data on the website should match reasonably well the data in the datasheet as the RF lines' insertion loss is deembeded.  

    However, I just checked Rx data and I believe this data set was taken with old subcircuit bias values and thus is is slightly low (about 1 dB).

    I have attached updated S-params below that used the Nominal bias values shown in the datasheet.

    ADAR1000_S-PAR.zip

  • +1
    •  Analog Employees 
    on Aug 9, 2021 3:49 PM in reply to Lee Jaegook

    Transmit and Receive Switching time is defined as the time from the TR pin at 50% of its final value to the RF signal at 90% of its final value.  The RF signal was detected using the fast envelope detector ADL6012. 

    The Phase and Gain Switching time was also measured using the ADL6012, but it was referenced at 50% of the TX_LOAD or RX_LOAD pins. 

    Phase switching time can be measured by detecting the resultant magnitude of 2 combined Rx channels.  If the channels are in-phase, the resultant output will be twice as big relative to a single driven channel.  If the channels are out-of-phase by 180 degrees, the signals will cancel each other out and the resultant magnitude will just be noise. 

  • Hi, jdobler

    I have additional questions.

    1. SPI Control Speed is 25MHz, is there any way to improve the speed? (I want it to run faster.)
    2. I want to check PA Bias in ADAR1000-EVAL. Is there any way?
    3. We are testing three ADAR1000-EVALs. What is the current applied to -5V? It shows 0mA from the power supply. It seems that this value is too small to be checked. Am I interpreting it in the right way?