Modernization of Frequency Synthesizers of the VHF Radios

The trends and prospects of the development of modern radio communication systems and complexes, the features of the use of frequency synthesizers (FS) based on the pulse-phase frequency auto-tuning ring in modern radio communications are analyzed. The results of the modernization of the FS on the integrated circuit (IC) HMC704 for receiving and transmitting devices of VHF radio stations are presented. The modeling of the main nodes of the upgraded FS in the TI PLLatinumSim program was carried out. The values of the LPF elements and the power spectral density of the phase noise of the FS output signal on the LMX2594 IC are calculated. Due to the possibility of using a high comparison frequency in the frequency-phase detector, it was possible to improve the weight and size indicators, increase the speed and purity of the spectrum of the output signal of the upgraded FS, which is confirmed by the results of modeling and experimental studies of the current synthesizer layout.