Power measurement of thermal noise
|471 - Abstract:|
|The European Space Agency has developed a digital circuit to measure the effective voltage of thermal noise in applications where integration time is not critical. This digital circuit makes use of the zero-mean Gaussian statistics of thermal noise and includes one module containing a sample stage and a calculation circuit. The organization seeks license agreements and industrial partners.|
Description of the offer:
The digital circuit allows measuring the power of thermal noise.
The thermal noise power is defined by a calculation circuit including:
- A correlator paced by a clock at said sampling period and which discloses a comparison logic circuit
- A circuit to determine a representative value of the effective voltage
The voltage value is a function of the difference between the number of times that the comparison logic voltage is above and below to the given threshold, over an integration duration corresponding to N samples of the signal.
The period is paced by a sampler stage comprising:
- A comparator which allows representing if the voltage value is or is not above said threshold
- A flip-flop which represents, for each period of said clock signal, a value of the logic signal at the output of the comparator
A device including this digital circuit requires an increased integration time to compensate its intrinsic lower sensitivity with respect to conventional analogue square law detectors. Moreover, the device will have a high linearity over a wide dynamic range.
Innovations and advantages of the offer:
This circuit measures the power of thermal noise (equivalently its effective voltage) by digital means taking advantage of the statistics of thermal noise. It avoids the use of square-law detectors and therefore has a potentially larger dynamic range and better stability over temperature. The drawback is its relatively poorer sensitivity which makes it worth considering only in applications where long integration times are possible.
Domain of Application:
This invention can be used in several sectors, in particular for devices used for applications where the offsets (such as thermal offsets of the threshold voltage) are not significant, for example in radiometric systems.
- Medical/Health related
Last update: 15 January 2013