y33t
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Does anyone know the exact value of the highest frequency generated by man ? The waveform and amplitude doesn't matter, it can be sinusoidal, PWM or what ever.
mfb said:Send visible light on a ~500nm-antenna, and you have electric alternating current of 6*1014 Hz. Use ultraviolet light and a 10nm-antenna, and you get 3*1016 Hz. The limit is just the material - a wavelength as short as the distance between atoms does not make sense as "electrical signal".
mfb said:The limit for computing is not the generated frequency, the issue is to work with it. You can produce signals with 600THz, but the logic gates are not quick enough to handle this, and signal delays are another problem.
Yes, and the reason is simply that a higher frequency would not be useful.y33t said:We can generate signals with microcontrollers, FPGA's, external DAC's and etc at any frequency depending on the boundaries of that IC. For example a PIC mcu can generate a 20KHz signal but it can't generate MHz or above. A midclass FPGA can generate a few MHz or GHz but not above.
I do now know why you dislike the optical approach. However, 3 NOT gates in a row can give an oscillating signal, and transistors are close to 1 THz.What I was trying to ask is that what is the limit that can be generated electrically . At this point I think we come up with your expression above, changing signal amplitude over time is the generating part and this is determined by the response time of the switching gates.
See the fastest transistor link.Can you point me to a paper or writing for this particular problem you mentioned above (lack of speed originating from logic gates) ?
You have an electric potential oscillating at this frequency. How to use this is a completely different question.On the other hand, I haven't come across any article or study that they could generated 600THz electrical signal by exposing a monochromatic light source to the wavelength-equivalent antenna. Is it really that easy, hold some laser to a very tiny antenna and you have your 600THz clock ?
mfb said:Rotation of a macroscopic object? 1MHz, with graphene.