[time-nuts] Flicker Noise Reduction

[jimlux]

On 11/18/20 4:59 PM, Richard (Rick) Karlquist wrote:
> I suspect that, whatever this is, only applies to 1/f mechanisms
> specific to THz, based on the last sentence.  One of my
> former clients did a PhD at Stanford on 1/f noise and
> his dissertation certainly had no magic bullets to
> mitigate 1/f noise.
> 
> There is some frequency, which I am fairly sure is less
> than a THz, above such that the usual equations for so-called
> Johnson noise no longer apply.  FWIW.
> 
> I don't blame you for not wanting to invest $15 or whatever it
> is only to see it and be disappointed.  Are you sure the
> author(s) hasn't published a version of it on his own web page?
> 
> I am guessing that this might be a reinvented transposed gain
> oscillator (TGO) used for the LO, where the LO is the original
> source of the noise.
> 
> Rick N6RK
> 
> On 11/18/2020 11:13 AM, Bruce Hunter via time-nuts wrote:
>> Can anyone who subscribes to these transactions report on this?  I 
>> dropped my subscription.
>> In this letter, a novel 1/f noise mitigation technique is presented to 
>> improve the receiver 1/f noise performance of a 670 GHz receiver. Time 
>> domain 1/f noise corrected samples are compared with samples obtained 
>> without the correction. Spectral domain analysis shows that the 1/f 
>> noise mitigation method improves the receiver noise performance by 19 
>> dB in the receiver under test. The presented 1/f noise mitigation 
>> technique can be applied to any direct-detection receiver in the THz 
>> frequency range.Published in: IEEE Transactions on Terahertz Science 
>> and Technology ( Early Access )Page(s):  1 - 1Date of Publication: 06 
>> November 2020
>>


The authors are at JPL, Northrup Grumman, and Colorado State, Ft Collins.

Since it was funded by NASA, it will show up on JPL's tech report server 
in a bit.

I'd send the author mehmet.ogut at jpl.nasa.gov an email asking for a 
preprint copy. He should be happy to send it to you.  Let me know if you 
need help - I've met some other co-authors (i.e. Al Tanner) but don't 
know them well.
You might also check Colorado State's website - they might have a 
preprint up (or on arXive).

It's targeting 670 GHz receivers for cubesats (TWICE is the project name)


Not a Dicke Switch:
The addition of a Dicke switch is useful for reducing 1/f noise
in radiometers [5],[8]. However, only limited work on switches
has been done at THz frequencies [9]. This, in turn, makes
Dicke-switching architecture impractical for radiometry in the
THz range. Therefore, a significant need exists to address 1/f
noise in THz direct detection receivers

The proposed mitigation technique relies on tracking the
rapid gain variations in the radiometer due to 1/f noise and
correcting them by generating a baseline state in the first
amplification stage of the low noise amplifier (LNA). The
proposed 1/f noise mitigation method can be applied to any
receiver, but it is especially valuable for THz receivers since
any switch inserted between the antenna and the low-noise
amplifiers will add high insertion loss at these high frequencies,