heterodyne frequency grid
permissible frequency range and for the constant frequency grid of the heterodyne in a wideband receiver at which, in the pass band, harmonic and combination components of the form |+/-nFс+/-mFг| are absent.
A wideband receiver in the regime of work with a heterodyne frequency grid performs an immediate survey of an input frequency range, without time loss connected with tuning the heterodyne, and increases sensitivity by 10Log k, dB, in comparison with a receiver working in the regime with one constant heterodyne frequency. However, in this case, the number of receiving channels increases proportionally to narrowing the pass band of the frequency transformer without harmonic and combination components.
Frequency transform is considered with using the analytical method for evaluation of transform parameters. Physical sense and mathematical foundations of the method are considered.
An example of evaluation of parameters of the wideband receiver with heterodyne frequency grid is presented.
Recommendations on choosing frequency parts dividing the input range are given and expressions for mean frequencies of this parts, their lower and upper bounds, and heterodyne frequencies are presented.
Spectral diagrams for work frequency parts are shown, confirming the fact that, at the maximally wide frequency range in the pass band of the transformer, which is integer times less than the total input range width, given harmonic and combination components are absent.