A DDS-PLL hybrid based fast settling wideband frequency synthesizer for frequency hopping radios

The new generation software defined radios implement a wideband RF front-end which calls for a wideband frequency synthesizer for generating the local oscillator signal. Moreover military applications demands frequency hopping capability also. A single wideband synthesizer was developed based on a translation loop architecture using a DDS and two PLLs in conjunction with a frequency mixer. The highlights of this design include fast switching speed and narrow tuning resolution advantages of DDS combined with the very low phase noise and spurious performance of PLL. An exhaustive simulation of this design done in AWR VSS software is given in reference 1.