PSK highest frequency possible.

Hi!
Can PSK be done at a frequency in MHz? It would be great if you can give me such a circuit. Ideally, it should have been working at 2.4 GHz, but the highest possible PSK frequency is a limit, so the higher the frequency, the better. Thanks a lot!

Bala

In a modulated signal the practical limit of the modulation frequency is some small fraction of the carrier frequency. The reason is that a wide bandwidth modulation scheme results in a wide bandwidth signal which has the potential to interfere with adjacent channels.

Example: 10Mb/sec Ethernet would be impractical on RF channels below several hundred Megahertz. If you did this at say 100 MHz. then the signal would occupy 95-105 MHz. wiping out a goodly portion of the FM band. Sure to annoy those classical music affcinados.

As you go up in frequency to get more bandwidth the ability to propagate the signal goes down, the ability to create a powerful signal goes down, the ability to get a signal from a transmitter to an antenna drops like a piece of brown in the rain. The action in communication systems is in the other direction, how to get very efficient minimum bandwidth signals which can proagate effectively.

PSK31 widely used by hams allows several conversations on a single carrier frequency. It uses a very efficient varicode and has a bandwidth of 31 Hz.

Hi!
hey, thanks for replying! yeah, i get those constraints. I am looking for a transmitter that has a range of about 15m or so. I will look for PSK31. Thanks for that, what is the max possible frequency limit for this?

PSK is usually used in bandwidth limited applications. If your desired range is only 15m's you can use as much bandwidth as you want as long as the signal is really weak.