Just another Tip & sorry if you already know this. For your Rigol it may be useful to turn off the 10db Attenuation and Switch on the PreAmplifier which will have the positive effect of lowering the noise floor and may make some of the additional frequencies visible. Also has you only seem interested between 30Meg and 1Ghz change your start and stop frequencies to be closer to what you want to look at have make your bandwith smaller you may find the plots will give you more useful data. Oh and also using the dBuV scale in the Rigol will align the scales with your test house, even though the measurements are only relative