Hi
I am just starting here so I apologies if this is in the wrong section of the forum.
The frequency synthesis using PLLs and VCOs are very popular in the RF world and can be found in nearly every high end telecommunication equipments. So as an RF enthusiast and an Arduino lover ,I thought it would be nice to combine both in a project that use the Arduino to control the PLL and make a shield for that, and I am sharing it hoping that someone might find it useful and have fun with it as I did.
The PLL frequency synthesizer shield (RF BOARD) is based on the analogue devices ADF-4360-8 chip which include a PLL and an integrated VCO. It can be used from 65 to 400 MHZ and can be replaced with another model of the same series that covers frequencies up into the Ghz bands
The output is a very accurate, well defined and stable RF signal at the desired frequency which can be set through the Arduino .
Mine is in the aviation band from 110 to 130 MHz , I selected this band as an example and for future aviation receiver project using the Arduino, , the output signal would be mixed with an RF input signal from the antenna to produce a 10.7 IF in a separate circuit and delivers it to the detector and the audio sections of the receiver. This is why the output frequency of the synthesizer should be 10.7 MHz higher than the desired received RF signal
Here is the PLL synthesizer RF board, notice some mistakes I made in the board design, hence the extra wires on top , I'll try to correct those and make the board again
And here is the I/O board which is mainly the push-buttons to change the frequency up and down, and the 7 seg. digits of the Frequency read out, all controlled by the Arduino UNO
The board to the right is an older version
Here is the boards in action
and here is the output RF signal at 130.3 Mhz which corrospond to a mixer output frequency of 119.6 Mhz
I am using Eagle to produce the boards schematics and layouts and I will share them as soon as I correct some small mistakes there , as time permits.
The code for the Arduino uses the SPI library and can be used with many Analoge devices chips of different kinds to program them with Arduino , and I'll post it here soon too
Thanks for your time and I hope you find it useful.
