We have got HMC8191. When we apply LO signal to 23 pin we have no response in the IF outputs. So we tried to send a 12 Hz 15 dBm signal to various inputs.
When we apply LO signal to 24 pin we have some response in the IF outputs.
But when we smoothly reduce amplitude of signal at 24 pin, amplitude of output signal (pin 10 and 12) decreases smoothly too. At the same time if amplitude of signal at 16 pin, becomes below a certain level the output signal falls sharply. It seems that 24 pin reveal itself more as RF input then LO. And the behavior of 16 pin looks like LO input then RF.

Is it correct behavior of HMC8191? What can be wrong?

What is the correct pin configuration and function of HMC8191?