Solved A student working with a set of signal generators Circuit Diagram You typically use one of the many cheap RF synthesizers which include an oscillator, a (very advanced) PLL and an interface to receive a lower-frequency reference from e.g. an external quartz oscillator, or to drive a quartz itself to generate a low-frequency reference. The signal generation process starts with the oscillator, whichgenerates a stable and repetitive waveform, A radio frequency (RF) generator generates high-frequency signals in the radio frequency spectrum, typically ranging from a few kilohertz to several gigahertz. These generators are crucial for various applications in wireless The oscillator circuit we will build with a 7414 schmitt trigger inverter chip to produce a 1Hz signal is shown below. on the other hand, if you want a very high-frequency signal, you would use a small resistor and a small capacitor, such as a capacitor in the picofarads. When you have a capacitor in the picofarads, it can only hold a small
This generator should be able to sweep through a range of frequencies and the range would be 150 KHz to 80 MHz. the sweep rate is not more than 1.5*10^-3 decades/s. There are different oscillator topoplogies, but I can't use, say a purely RC oscillator or a crystal oscillator as they offer a static method of generation (single frequency).
RF Signal Generator : 8 Steps (with Pictures) Circuit Diagram
If the frequency is too low, you will get visible flickering on the LED, and if too high, the control device or the load will not be able to turn on and off fast enough. We have seen how to build a simple astable oscillator with the 555 timer that generates a pulse width modulation signal to control any any analog device. The output signal of the RF generator is an analog sine (AM modulated or not modulated ) signal. At high frequencies its amplitude decreases a lot. To be able to measure the frequency of the signal with the frequency counter a pre-amplifier / signal form shaper is needed. I took the circuit presented here and soldered it on small perfoboard.
The PLL can only remain in lock with the reference oscillator by producing the same frequency out of the divider. This means that the VCO must generate a frequency \(N\) times higher than the reference oscillator. We can use the VCO output as desired. In order to change the output frequency, all that needs to be changed is the divider ratio. \$\begingroup\$ @Parisa if you need better performance (performance not stated in question) then choose a better VCO. The point of this answer was to show what is possible. This topology (i.e. using a PLL) is probably going to give the best results for most applications but, if you are not too bothered about centre-frequency drift, look for a VCO that has much finer tuning and run it open loop 1. Sinusoidal Oscillators - these are known as Harmonic Oscillators and are generally a "LC Tuned-feedback" or "RC tuned-feedback" type Oscillator that generates a purely sinusoidal waveform which is of constant amplitude and frequency.; 2. Non-Sinusoidal Oscillators - these are known as Relaxation Oscillators and generate complex non-sinusoidal waveforms that changes very quickly
