¿ªÔÆÌåÓý

  1. Test-Equipment-Design-Construction
  2. Messages
Single Messages Topics Expanded Polls

Re: Possible designs for a Ultra low noise 1 Hz to 100kHz amplifier for Phase Noise Analyzer?

 

On Sat, 20 Aug 2022 at 23:30, F1EKU <rfconsulting.fr@...> wrote:
Hi Dave,
Paralleling transistors or amplifiers simply increases the current of phase correlated signals by a factor of N and of non-phase correlated signals (Gaussian noise for example) by a factor of square root of N.
Thus, we obtain an improvement of the signal-to-noise ratio of 6 dB for 4 transistors, 12 dB for 16 transistors, and so on.
This solution was widely used in Hi-Fi several decades ago in the glory days of vinyl records, particularly for moving coil type cells.
F1EKU

Thank you. I have never seen this done at RF / microwave frequencies, where I have more experience.?

Dave?
--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...

Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom
Join [email protected] to automatically receive all group messages.