I am not sure what is the maximum external LO input frequency can the AD9371 can accept.
On Page 55, the datasheet Rev. B mentions The AD9371 provides two external LO inputs to allow an external synthesizer to be used with the device. These inputs must be 2× the desired LO frequency. Note that operation for the external LO option is limited to a maximum of 4000 MHz.
However on Page 7, the datasheet states 8000MHz as the maximum frequency.
The intention is to use a DDS to supply the external LO to the AD9371. The input signal is between 4 to 5GHz.
Can someone please confirm the maximum external LO frequency that can be accepted by the AD9371?