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ADF4355 for Chirp Generation

Question asked by Renegade on Nov 10, 2016
Latest reply on Nov 20, 2016 by Renegade



I am looking to use this VCO+PLL integrated circuit (ADF4355) for chirp generation at either S or C ISM bands, however I am unsure whether this device would be suitable for this application. I was advised that it was perfect for spot generation, but whether it could handle frequency sweeps of bandwidths 50 MHz or potentially 150 MHz for the ISM bands respectively is questionable. Does anyone know whether it would be possible to achieve this with this IC; potentially including some smart programming tricks, control circuitry etc? Or could anyone kindly recommend any alternative IC's which could satisfy my requirements? 


I am also looking to achieve a phase centre at each frequency step in the ramp, I know this would easily be possible with a DDS however I am constrained in terms of cost and complexity and my very last option would be using a DDS. My current setup involves a high resolution DAC 14 bit @ 125MHz potentially driving the VCO tune line. I can already envision issues with the internal PLL loop bandwidth and ensuring the frequency step is phase centred, but pushed for utilising this DAC. 


The PRF's of my ramps will be between 500Hz to 10KHz, if this information is of any use. I look forward to your reply. 


Regards, J Patel