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ADL5375-15 sideband suppression and other

Question asked by ricky on Jan 20, 2015
Latest reply on Feb 1, 2015 by ricky

Hi All,


One of my customers is using ADL5375-15 Quadrature Modulator for his prototype board.

High-Speed DAC generates analog I/Q signal and is fed to ADL5375-15 through reconstruction filter designed by him.

Attached file “SSB-compression” shows sideband suppression performance taken by him.

Frequency condition is f0=3GHz, I/Q input freq=27MHz, LO=3GHz.

  • (1)  He made gain and phase calibration at f0 frequency. After calibration, he made sideband suppression performance test as shown attached file. He would like to confirm with you about the suppression performance as around -50dB and -47dB at around f0-8.5MHz is reasonable one.
  • (2)  He also made frequency bandwidth test. For the test, he first bypass the reconstruction filter, it means DAC output is directly fed to ADL5375-15. The DAC works at 250MSPS data rate. The response curve is attached as QMOD-OUT file. It down around 3dB at f0+/- 24MHz. I think that one of reason is Sinx/x roll-off, however roll-off amount is too large. Is my understanding is correct? Do you have any other advice on this?


Thank you for your help.