HMC985A-DIE shows drop of attenuation at 45 GHz

Hi Aaron,

could you please share the input output return losses of HMC985A as well?

Thanks

Sinan

S parameter of 985A:

S parameter of 985:

Sinan, nny feedback about this issue?

Thanks

Hi Sinan, merry Christmas

These days we found that this gold bond affects the position of the drop.

Hi Aaron,

Can you apply double bondwire or a ribbon? The inductance on the supply capacitors usually affects the high frequency performance. Glad you have found the sensitivity. The pad opening is 86um x 83um and you may try double bond or 2mil / 3 mil ribbon.

Hope this helps 

Sinan  

Hi Sinan,

The pad 4 is only 0.086mm, it is impossible to double bond or wider 2mil ribbon.

On datasheet it is also suggested that 1mil gold wire should be used.

Hi Aaron,

Did you use 100pF caps? What is the series resonance frequency of those caps? Might be the root cause as well.

PDF

We use this 100pF capacitor 

Hi Aaron, 

These capacitors are rated up to 26GHz. Is it possible to build this assembly with a 50GHz rated cap? 26GHz versions might have series resonance frequency within the band of HMC985A