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How to achieve flat RF output response from HMC833 PLL IC across freq Band?

Question asked by Rajan_chd on Nov 28, 2015
Latest reply on Sep 27, 2016 by dyoung1


I am using HMC833 PLL for generating set of frequencies ranging from 1100MHz to 1700MHz.

At present, I am writing the designated registers to generate required frequency spot within above mentioned band.

As the frequency spots varies the RF output level is also varies w.r.t frequency. The RF output response curve is almost similar to the one given in the HMC833 datasheet. I know that we have four RF gain settings to control the RF output level.


In HMC833 evaluation GUI (from CD in evaluation kit), there is an option to increment the frequency by given number (this number needs to be entered by user). To use this function, I started the frequency from 1100MHz then incremented it by 1MHz step and reached 1700MHz. On the spectrum analyser I got almost FLAT RF output response from 1100MHz to 1700MHz.


I want FLAT RF output response across my freq band. I feel changing the RF gain register value (00,01,10,11) with respect to particular frequency spot is a lengthy process.


Is there any other way (short and effective) to my requirement of getting flat response from HMC833?