Arrangement in a radar system for correction of phase and amplitude errors in a video signal

Claim 1

1 Arrangement in the receiver of a coherent radar system for correcting phase and amplitude errors occurring when the incoming signal is divided into two quadrature channels in the system signal receiver, there being arranged a quadrature detector for said division of the incoming signal, an analogue-digital converter for converting the signals divided in the quadrature detector to corresponding digital values, and a correction unit for multiplying and adding the divided signals by, and to a first and second correction signal derived from said phase and amplitude errors, characterized by a regulating network (RN) for forming the first and the second correction signal, said network containing two regulating loops, of which one Loop contains a multiplier unit (M5, M7) for forming the product signal from the signals (S and S Q ) from the correction unit (KE) in the respective channels (I and Q), a summator unit (S1, R4) and a first comparator unit (JF1, JF3) for at Least establishing the polarity of the product signal after the signal has been formed, a first register unit (R1, T1; R4) for forming a value of the correction signal answering to the phase error in response to the polarity established by the first comparator circuit, the second- loop contains two quantity value-forming units (B1, B2 or B3, B4) and,an adding circuit (A3, A4) for forming a difference signal between the quantities of said signals (S I and S Q ) from the correction unit (KE), a second comparator circuit (JF2, JF4) for establishing the polarity of said difference signal, a second register unit (R2, D1, D2, M6 and R3) for forming a value of the correction signal answering to the amplitude error in response to what polarity has been estabLished by the second comparator circuit (JF2, JF4).