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Amplifiers don't Amplify signal

I have a problem with the hmc863alc4 and hmc752alc4 amplifiers.

I apply the process as Mr. Jim explained to me  the last time to supply voltage of these amplifiers.

The PA amplifier (hmc863alc4) attenuates my signal instead of amplifying it.

Then the LNA amplifier (hmc752alc4) does not act on the signal. It doesn't amplify it.

Please help me

[locked by: aandrews at 3:57 PM (GMT -5) on 20 Jan 2022]
[unlocked by: aandrews at 3:59 PM (GMT -5) on 20 Jan 2022]
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  • Oups 

    In My real circuit, Amplifiers are connected correctly. I try to find solution at this problem since 3 weeks. 

    I have followed your instructions step by step.

    But I don't know why the amplifiers  refuse to work properly.

    Why does the LNA let the signal pass without amplifying it?

    Why is the PA attenuating the signal?

  • Hi IBMOTO,

                        Can you test the amplifier by itself. Bias it up and verify the dc current is correct. The add a small signal, say, -15 dBm and confirm what the output power is? Need to determine if the amp EVB is defective.


    Jim B

  • The LNA amplifier is now working.
    But the PA refuses.
    When plugged in, it attenuates my signal by 50 dB.
    Even when I turn it off, I observe the same attenuation.
    So I conclude that the amp does not work.
    I do not know why.
    However, I send to its input a signal of - 20 dBm.
    Also, I checked that the current is flowing well in the amp on pins 1 and 7

    help me please

  • Hi IBMOTO,

                          At this point since the part seems to bias but no output, I recommend contacting the distributor your purchased it through and get an RMA to send it back. Ask them to send a replacement as the board doesn't work.


    Jim B