Can Hittite attentuators work for 9kHz to 100MHz, such as HMC624?

Hello everyone. I am designing with the HMC624 attentuator IC from Hittite Microwave. However, I found that when the input frequency is lower than 25MHz, the output won't work with the control word (upper than 25MHz it works well). I use a 4.7 uF capacitor for dc blocking in for each input and output side. Would anybody bring me some suggetions? Any advice is welcome.
:grin:

Did you notice, that the ACGx capacitors must be dimensioned for lowest frequency of operation? See pin description.

Unfortunately, Hittite is claiming DC operation without giving a application circuit. One would expect in- and output as well as ACGx biased to a fixed voltage, respectively a dual supply used for the device in thais case. You may want to ask Hittite support about the DC point. I didn't check the datasheet of similar devices, there may be additional material.

Many thanks for FvM. I had better ask the application engineers of Hittite. It is a bit funny that I emailed them a period of time before without any replies.