Noise figure measurement by your bootstraps

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Phil Hobbs 12 years ago

Jerry Johnson, pillar and chief guru of the Amateur Microwaves mailing list, posted a link to this paper, which is a method for calibrating noise figure without either a calibrated noise source or a calibrated attenuator. I'm not sure how well it does in the presence of various amounts of mismatch, but it's worth analyzing more carefully than I have time for at present.

So for your radio frequency delectation,

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Cute trick. I'll try it out one of these times.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net

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bloggs.fredbloggs.fred 12 years ago

Too much mental midgeting over dumb little conversion and definition equations, and too little reasoning. How anyone can read this stuff is beyond me.

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Phil Hobbs 12 years ago

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If you ever needed to make good noise figure measurements, you might be more motivated.

Cheers

Phil Hobbs

Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net

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George Herold 12 years ago

I only read it quickly... So if I understand, with two known noise sources (or sources with a known ratio) you measure the "real" noise and then infer the amplifier (DUT) noise. Is that correct? That means subtracting two bigger numbers to get the difference?

I also might worry about the step attenuator changing the bandwidth of the known source... but I guess if it's going into a spectrum analyzer you'd see that.

George H.

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Noise figure measurement by your bootstraps

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