I use the FR4 substrate to do the 1.6mm double-layer PCB board, clock input using balun single-ended input, differential output way, and found that SYS_CLK pin does not have frequency output above 1.2GHz. I wonder whether or not this problem is caused by not considering 50 oh matching.
The second question is that I now want to use the reference circuit clock buffer. According the referecne circuit, there is a 100 OHM DIFF PAIR, what is the meaning. Does that mean input should match 100 ohm differential input, and using microstrip line design?