Basic RF transceiver with RF2713 IC

[subzero]

Hi all,

I'm relatively new to electronics and wanted to further my understanding by embarking on a basic RF transceiver design based around the RF2713 IC. Does anyone have any experience in developing a simple QPSK transceiver based around this IC in the sub-Mhz frequency (around 200 to 400kHz) range?

Initially I want to develop a non-PA version for learning (keeping the antennas relatively close together), which this seems to involve using a DAC to RF2713 to antenna (for the transmitter), and an antenna to RF2713 to ADC for the receiver.

Could anybody recommend any simple to use DACs / ADCs (or basic equivalents), and a basic circuit for the above?

Thanks!

 

[pgib8]

I don't have this experience but I think you still need to mix your signal with a carrier. Maybe your carrier is 0Hz and you're doing baseband only, I don't know how that would work. I'm also not sure how these low frequencies would work with little antennas. I'm also not sure if you want to dive right into RF if you are still new to electronics.
These are just some thoughts.
Also I'm sure you know you can get complete RF modules including antenna for super cheap, which can do your modulation. In any case, you should post the progress of your project, I would certainly be interested.

 

[sundy]

I am not associated with this company, I do use their FM transmitter to play music in my warehouse. The have lots of kits including FM transmitters, they might have receivers. not sure. It would be a good way to get your feet wet to build and modify kits IMHO. http://www.ramseyelectronics.com/

 

[subzero]

I don't have this experience but I think you still need to mix your signal with a carrier. Maybe your carrier is 0Hz and you're doing baseband only, I don't know how that would work. I'm also not sure how these low frequencies would work with little antennas. I'm also not sure if you want to dive right into RF if you are still new to electronics.
These are just some thoughts.
Also I'm sure you know you can get complete RF modules including antenna for super cheap, which can do your modulation. In any case, you should post the progress of your project, I would certainly be interested.

Thanks for the reply.

In my initial research, I'm currently going with using a digital signal encoded by a NRZ encoder, and then modulating this signal via the RF2713 modulator IC. There seem to be a crop of NRZ TO RZ encoder ICs, but bizarrely no RZ to NRZ encoders ICs. Presumably a NRZ encoder could be built with a single opamp?

So the basic RF transmitter block (for a QPSK transmitter) would consist of a bitstream (from a uC) -> demux (I/Q bit splitter) -> NRZ -> RF2713 -> antenna

This seems to encompass the basic RF transmitter interface (without PA) - am I missing anything?

 

[subzero]

I am not associated with this company, I do use their FM transmitter to play music in my warehouse. The have lots of kits including FM transmitters, they might have receivers. not sure. It would be a good way to get your feet wet to build and modify kits IMHO. http://www.ramseyelectronics.com/

Thanks for the link. I checked out the site, but they don't seem to be making the kits anymore.

 

[sundy]

Thanks for the link. I checked out the site, but they don't seem to be making the kits anymore.

I see that they have moved everything to Amazon. If you search for Ramsey on Amazon it should come up.