LTC5594 AC-coupled interface with AD9684 AD9680 or similar ADCs

Hi everybody,

I need your support to implement a proper ac coupled interface between LTC5594 I/q demodulator IF OUT and AD9684 analog input. There is no reference Vcm to feed LTC9684 so that DC coupling is a big deal. 
In datasheet of LTC9684 there is some IF out termination resistor to set output current 18mA. There is an application circuit at page 32. This circuit shows DC-coupled interface between LTC5594 and AD9208 and the required termination resistors are 73.2ohm to GND where ADC input impedance 200ohm. AD9684 has a similar input structure with AD9208. 

I will be very glad if you advice me an AC-coupled interface and termination resistor value for the below application circuit