Frequency synthesizer is an important component of radar tracking system for remote sensing. Synthesizers generate wideband radio frequency signals with high frequency resolution. Parameters of radar depend on the synthesizers phase noise. This paper presents algorithm for structural design of signal generators based on various synthesis methods: direct, indirect and hybrid ones. Specialized software based on presented algorithm was developed in this work. Software allows calculating frequency ratios in the structure of synthesizers, selecting optimal parameters which can provide low phase noise level. Also software allows performing mathematical modelling and analysis of phase noise power spectral density (PSD) of frequency synthesizers. Presented algorithm and software can be useful for developers of remote sensing radio systems.