METHOD OF GENERATING, MEASURING PARAMETERS AND PROCESSING SIGNALS FOR DOUBLE-FREQUENCY HEADING-GLIDE PATH LANDING SYSTEM OF AIRCRAFT Russian patent published in 2013 - IPC H03L7/16 G01S1/16 

FIELD: radio engineering, communication.

SUBSTANCE: operating frequency of direct digital synthesis (DDS) microchips is programmed, modulation signals are generated in digital form based on reduced dependencies on narrow channel signal modulation, wide channel signal modulation, narrow channel carrier frequency and frequency offset of the narrow and wide channels. Further, analogue-to-digital conversion of the obtained signal is performed; the digital signal is filtered; narrow and wide channel signals are separated by shifting channel frequency to "zero" frequency by multiplying with a quadrature signal of the corresponding frequency; the obtained quadrature signals are filtered and demixed. Signal parameters are then measured and gain constants and modulation factors of each transmitter channel are corrected based on measurement results and transmitter output signals are equalised according to phase.

EFFECT: simple realisation of amplitude-phase distribution for different antenna arrays and enabling correction of amplitude-phase distribution when tuning a radio beacon on-site.

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