USB RTLSDR, Need 3.3 and 1.2 power rails. Best option for low noise/ripple 1.2v

[rwgast_lowlevellogicdesin]

So im just constructing some mods for an RTL-SDR dead bug style on copper clad, I intend to actually encase it all in copper clad seems like and easy way to turn you ground plane into a shield!

Anyways im tying to get everything off the PCB that's not needed and replace the power rails. Im using a sheilded USB cable with a  ton of feright's either slipped on or wrapped as chokes. This then runs in to an LM2937 LDO to create the 3.3v rail. Ive tested it out it seems to have about 700uV ripple under 500mA load.

So I need to figure out a way to do the 1.2v rail, to replace the switching supply on board. Im trying to just use things I have around. And the three options Ive come up with are as follows....

LM317 droping out from 5v USB
LT3080 dropping from 3.3v regulator
A few diodes dropping down from 3.3 regulator.

I have never used diodes to drop off voltage for a rail, the 1.2v supply takes about 200mA of current. I know I can source the appropriate diodes for this. My question is which one of these options will give me the cleanest power out? Im not sure if diodes emmit any noise kind of like resistor johnson noise issues....

So what do you guys reccomend.

[tszaboo]

None of the above. The 317 is usually too noisy for it, and goes down to 1.25, some might do 1.2
The diodes give you and unregulated voltage, and this is not the 70s anymore where ICs are expensive.
The LM3080 is just Linear Technology's joke that they can sell stuff doing the job of a half dollar IC for 4 dollars (Look Ma, only one ressitor!)

Use something like the TPS796. That has RF in it's name, should eb good for RF, right?

[rwgast_lowlevellogicdesin]

Well thanks for the tip, im looking at the TI part right now.... Its not money that was my concern its more of waiting around for the LDO to come.

I dont own a very good scope its only a 25mega sample  pc scope from parallax, but im seeing very little ripple on my LM2937, do you consider these good low noise LDOs? And is the 3080 pretty noisey, obviously you dont like it but i have a few on hand never used them.... just would like to know why its not a great part, other than the problems dave had with it trying to do something out of spec.