Bought one system for my self to disassemble. The main interest was to find out what have they used to implement this 3,3 GHz band. Here you can find post with overview of this system I did earlier.
In previous post I mentioned that both transmitter and receiver have chip with part number scraped off. However I managed to track the mystery chip in one evening, or so I think 🙂 I still need to sniff serial interface communication and by decoding it prove the fact. In this stage I only compared pin-out and parameters like recommended reference frequency. My strategy was to search for tuners, synthesizers, PLLs and similar ICs capable operating in this band and compare pin-out to one on the PCB boards. From the pin-out mysterious chip on transmitter and receiver seems to be the same even though in different package. Tx – QFN, Rx – VFQFN.
In my opinion the chip is MAX2870 or it’s family member a 23.5MHz to 6000MHz Fractional/Integer-N Synthesizer/VCO
In transmitter MAX2870 chip is used together with power amplifier chip RF5603 and quite a few discrete components supposedly used in audio/video modulation scheme. MAX2870 directly creates RF signal that is amplified and transmitted.
On a receiver side everything is more complex. MAX2870 is used to down-convert received signal to lower frequency of 479.50 MHz. This lower frequency signal is then fed to IF input of RTC6711 analog video receiver for 2,4Ghz band. This RichWave chip together with RTC6721 audio demodulator is used to extract audio and video signals.
Over all system looks decent and engineered to a standard, but I yet need to fly it in FPV aircraft to evaluate it’s real world performance.
Hope RF enthusiast will find this interesting, cheers!