A way of correction of DAA receiving channels characteristics using the heterodyne signal
Usually a problem of correction of a digital antenna array (DAA) channels characteristics is solved by applying an external pilot-signal or additional diversing of control signal with respect to radio frequency.
To minimize the hardware expenditures it is proposed to use unnominal heterodyne operational mode, which consists in changing the excitation conditions in a control period so to cause the generation of parasitic broadband or multimode signals. At the same time it is necessary to provide stable arising of intermediate frequency oscillation at mixer's output. In the event of a narrow pass band of intermediate frequency amplifiers such signal is quite suitable for equalization of complex transfer characteristics of receiving channels.
Slyusar, V.I.; Pokrovskij, V.I.; Sakhno, V.F. RF Patent No. 2103768 H 01 Q3/36, G 01 R 29/10. A way of amplitude-phase characteristics correction of primary channels of plane digital antenna array. Bull. Izobr., 1998.