In a typical PLL there are 3 critical parts: the voltage controlled oscillator, the phase comparator or detector and the loop filter.
#OPENTTD SIGNALS TUTORIAL PART 2 HOW TO#
If you are a bit rusty on PLL’s I will quickly explain the basics since it will help to understand how to program this chip later. It achieves this wide band signal generation by using a phase locked loop (PLL) with a reference oscillator and number of divider circuits. At the heart of this generator will be the ADF4351 synthesizer chip from Analog Devices. It will do this with 1kHz frequency resolution and adjustable output power levels. So in this post I will discuss my attempt (and work in progress) at building a RF signal generator that can generate signals from 35MHz up to 4.4GHz. Recently I noticed a number of people rolling their own by either using a chip from Analog Devices that goes up to 4.4GHz or one from Maxim which goes even higher up to 6GHz. The problem is that these devices are normally not cheap and most makers and hobbyists just can’t afford to buy expensive signal generators that can produce signals in the GHz range. Having a signal generator could be invaluable for these types of experiments and projects.
Sometimes you want to test the response of a filter and need to sweep through a range of frequencies or need to generate a carrier or clock frequency. When you start to experiment with radio frequency circuits and projects one of the tools that is a must have is a RF signal generator.