Electronman
New Member
So my circuit has reached to that freq, WoW
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Well several days ago I read a paper about creating audio from ultrasound. So I want to design a circuit to do a similar task.
I have to filter out the output to create SSB or VSB somehow.
You guys, please let me know If those high pass filters which I designed (the above pictures) cause the output to be VSB if they do not remove the toltal lower side band?
If I am can not to create a good filter for SSB then I want to create a filter to truncated the lower sideband of the dsb with carrier signal. Any suggetion?
Your 40kHz carrier is a square-wave that has a lot of harmonics. If it is a perfect square-wave then its even-numbered harmonics like 80kHz, 160kHz etc. should have a very low level. The 3rd harmonic at 120kHz will have a high amplitude.
I've not followed the rest of this thread, but bat detector circuits are commonplace and simple - I've no idea why you're talking about sidebands and SSB?.
Mixer, local oscillator, audio low-pass filter - end of story.
A perfect square-wave is symmetrical. Then its even numbered harmonics are very low in amplitude (2nd, 4th, 6th, 8th harmonics etc).Why the third harmonic will have a higher amplitude than other ones?
There is a company that produces high power ultrasonic transmitters that are modulated with speech and a sophistocated algorithm. When the ultrasonic wave strikes an object like a statue in a muzeum then the speech appears to be produced from the statue.
The company claims that the ultrasonics can be modulated with different languages and the modulation can be heard when the beam hits a person. The beams are very directional so people over here can hear one language and people beside them can hear another language.
I don't know if the ultrasonic beams are single-sideband.