Need baseband transceiver for distance measurement between 2 radios
I am trying to do distance measurements between two radios. Now I have found a method I am confident will work, and does work in my simulations. As I know only the basics of RF design I had hope to find a near complete transceiver as an IC and make a circuit board for it. Unfortunately it seems that due to a few special requirements that there's very few options.
For my method to work I need access to the baseband. Most transceiver IC's I find takes a bit stream and data clk and converts it internally to the rf spectrum. This doesn't work for me as I lose precious information about the baseband.
Furthermore I am working in the 433 MHz range due to the improved penetration of that frequency (though 2.4 GHz would have made the IC choice much easier).
Do any of you know some ICs that could work?
Something like the Max2830 would work but it's only for 2.4 GHz. The MAX2510 could work, but I am unsure how many external filters/amplifiers should be added to get a complete receiver?
I hope some of you can help.
Can you please give more detail on your requirement "to have access to the baseband"
If the MAX 2510 is OK for your transmitter, you could build a different IF limiter and detector system by feeding the filter into your bit of kit instead of "LIMIN" (Pin 1). Perhaps a conventional FM receiver IF chip would do.
Frank
I send x periods of a periodic signal from radio A to radio B which then samples x and averages x -1 periods of the signal. After that radio B transmits x periods of the signal it received and radio A samples and averages x-1 periods. This gives a waveform that has been shifted by the distance between the two radios + whatever delay is present in the radios. By calculating the cross correlation between the original signal and the signal A receives from B the distance can be calculated if the delays in the radios are known.
To do it properly I need to sample the baseband at or above the Nyquist rate so I can recreate the signal that is received. A bitstream won't do. I will be using an FPGA and ADCs/DACs to sample and create the 1.5 MHz periodic baseband signal.
I hope that explains it a bit more.