04-11-2016, 11:07 AM
To Design and develop the PLL based Synthesizer in the Frequency range from (2-3) GHz.
1464357998-PLLAbstract.doc (Size: 21 KB / Downloads: 4)
The PLL based synthesizers are commonly used in receiver applications for producing the local oscillator frequencies. The time required for generation of the signals along with settling time is in the order of usec. The signals generated from the PLL based synthesizers will have good phase noise characteristics. The phase noise characteristics will play a lead role in conversion of input RF signal in the receiver to IF signal. The PLL consists of a phase comparator, which will produce an error voltage at the input of VCO. The error voltage will produce a frequency at the output of VCO. The PLL again will compare the frequency with the reference frequency. With applicable shift in voltage, VCO will try to correct the frequency shift and finally the error voltage will be zero. The frequency will be locked at this moment. The PLL loop consists of PLL, VCO, Amplifier and Directional coupler. The circuit can be controlled through three serial lines i.e. Data, load and Clock. Stable reference Oscillator i.e. Crystal Oscillator is required for reference for PLL. Currently PLL based synthesizers are available for producing frequency till 6 GHz. The fast frequency generation time will lead to increase in the search speed of overall receiver. The frequency can be produced with a step size of 1 Hz also. In the current application, the PLL based synthesizers is developed from 2-3 GHz with a step size of 10 MHz. The total hardware will be remotely controlled and the output (frequency and amplitude) can be measured on to the spectrum analyzer. The entire frequency can be viewed at the spectrum analyzer. The PLL used is from the Analog Device family.