Electronic – How does this wireless transceiver work


While messing with Arduino I came across this wireless transceiver. As a newbie in all this stuff, it's written that it operates at 2.4 GHz, so the transmitter crystal and receiver crystal must operate at 2.4 GHz, right? From the photo I can see that the crystal is 16 MHz which is 0.016 GHz. Probably I'm not getting it right, where am I mistaken?

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NRF24L01+ 2.4GHz Antenna Wireless Transceiver Module

Best Answer

Most wireless transmitters (of this type) use a crystal and a phase-locked-loop (PLL) to generate much higher frequencies. See this article: -

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Frequencies can be produced that are N*16MHz. This means, that for a 2.448GHz output, N equals 153. If N = 154, the output is 2.464GHz i.e. 16MHz higher.

There are other techniques that can do this but the PLL is most likely. Here's what the device says about itself: -

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The type of PLL used is called "fractional N" because it has the ability to produce higher frequencies that are spaced at a fraction of 16MHz.