Dear Sir

Please can you tell me about the phase noise of the HMC1096 active doubler? Why does the phase noise increase at high frequency offsets? What is the typical phase noise at higher frequency offsets than shown on the datasheet? Please can I have a plot of the typical phase noise at higher frequency offsets? Can the high frequency phase noise be reduced?

Thanks

John

Hi John,

The HMC1096 is a frequency multiplier so it impacts phase noise in 2 ways.

1) By doubling the frequency, the phase noise at the output will increase by 6dBc/Hz (20*LOG(N) where N = 2 (across all offsets that aren't being impacted by the noise floor).

2) Intrinsically, the multiplier along with it's amplifiers has what's called 'residual' or 'additive' phase noise. This adds linearly to the phase noise that would normally be present if you simply doubled the frequency without considering it's effects. The net effect is generally small and typically impacts offsets far beyond the carrier where it begins to dominate the total noise.

The noise in the plot shown in the datasheet is increasing due to limitations of the test setup. At offsets far from the carrier and small phase error prevents complete cancellation (assuming 2 unit test method).

We don't have data beyond what is shown in the datasheet.

Hope this helps,

Marty