What's in a name? Some companies use 'Ultra-', sounds very spiffy, just gotta be better than Very Low or Precise, 😉 ...
Words have meanings. They should not be abused. 'Quantum' should be preserved for things which actually use quantum phenomena. It would be legitimate to call a BJT 'quantum', as you can't explain a transistor without using quantum concepts. It does not follow that every circuit including a transistor is a quantum circuit.
What is quantum..?? quantum physics..? a cheesemaker..?? smallest possible amount of anything..?
what is a quantum device...?
what is a quantum device...?
That's a pretty close definition, if you can add in that it's also the smallest possible change in anything. For example, if you have monochromatic light with a frequency of v, you can have one photon with an energy of hv, two photons with an energy of 2hv, and so on, but you can't have 1.5 photons with an energy of 1.5hv. In other words, the energy is quantized, with each photon having one quantum of energy. Likewise, electronic charge- you can have any whole number multiple of e that you like, but you can't have 0.5 e or 2.4 e or...
A quantum device is one whose operation depends on the quantization of some physical property (e.g., a SQUID).
I know about the dual nature of light photons also the energy quants in change in energy levels on electrons i atomic structures. but how is this related to a quantum device (BJT JFET ect ect).
My physical analogy to these devices is pressure or flow controlled valves with voltage as pressure and current as flow, with this notion it is for me quite easy to understand circuits also to a degree where I can visualize distortion mechanisms.
So in our active devices a quantum amount will be the smallest possible change in flow or pressure (I and V) to generate a Current or Voltage modulation over the device..??
But is there such a lower limit..?? That would actually make our analog devices digital.. a quantum digital device.🙂
(quantum is also a cheese maker just for info)
My physical analogy to these devices is pressure or flow controlled valves with voltage as pressure and current as flow, with this notion it is for me quite easy to understand circuits also to a degree where I can visualize distortion mechanisms.
So in our active devices a quantum amount will be the smallest possible change in flow or pressure (I and V) to generate a Current or Voltage modulation over the device..??
But is there such a lower limit..?? That would actually make our analog devices digital.. a quantum digital device.🙂
(quantum is also a cheese maker just for info)
Your mental image (Vorstellung, I don't know the word in Danish) is useful for applying the devices in an engineering sense. One needs to consider the quantum solid state physics to get WHY that flow happens and why the Ebers-Moll equation works. This is important for physicists, less so for design engineers, who just need to know the equations and their limitations. And yes, current is quantized (more properly, charge is quantized), but the quanta are small enough that for most purposes, one can think of the properties of devices as being continuous. Yes, analog devices are digital.
So analog is digital with infinite resolution, which makes absolute sense..🙂 and yes for making and understanding circuits physical analogies are useful. (at least for a guy like me that has a solid mechanical foundation and education)
Danish for vorstellung is "at forestille sig" (to envision something)
Danish for vorstellung is "at forestille sig" (to envision something)
Very few things have quantum limited resolution. The resolution limits are generally much larger. For example, in optical spectroscopy, line resolution is determined by aperture or slit width, which are quite macroscopic. In recording tape, it's limited by bias frequency, particle density, and gap width. And so on.
And in our line of interest also by parasitics as our devices are not ideal, so their working capabilities are compromised and bandwidth limited. In audio the limitation is as you state it to a large degree our storage capability for the electronics, and of course for audio systems the frequency limitation on our speaker drivers.
The quantum BW limitation is only of academic interest, in practical terms it's a good thing to know that our valves (devices) leaks..🙂
The quantum BW limitation is only of academic interest, in practical terms it's a good thing to know that our valves (devices) leaks..🙂
'Random' noise in any area in audio is as good an example as any of how quantisation affects the audible quality of sound ...
Much perceived noise is not at all random.
Audible quantized noise from resistor of one type is different from resistor of another type. Digital quantization noise of 16bits system is way below human perceptual threshold relative to all other sources of noise in total signal path.
Audible quantized noise from resistor of one type is different from resistor of another type. Digital quantization noise of 16bits system is way below human perceptual threshold relative to all other sources of noise in total signal path.
Yes, as thermal noise does not require a quantum explanation. Circuits are classical objects, even if they contain quantum devices like BJTs.
Given the way that electrons interact, their discrete nature does not appear most of the time; it is not just that the charge is very small. To get shot noise you need uncorrelated electrons. Most circuit electrons are highly correlated, which is why we don't get partition noise at circuit junctions. This is the fundamental point which Hawksford missed when he talked about his fuzzy distortion.
Given the way that electrons interact, their discrete nature does not appear most of the time; it is not just that the charge is very small. To get shot noise you need uncorrelated electrons. Most circuit electrons are highly correlated, which is why we don't get partition noise at circuit junctions. This is the fundamental point which Hawksford missed when he talked about his fuzzy distortion.
Obviously, some people can't differentiate Quantization (physics) - Wikipedia, the free encyclopedia and Elementary charge - Wikipedia, the free encyclopedia ...
Perhaps, although I think you may find that these two concepts are related. The quantum theory of electrons (known as quantum electrodynamics) seems to require that all electrons be indistinguishable and therefore (among other things) have exactly the same charge.
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