US 7,403,156 B2 · Method and system for performing digital beam forming at intermediate frequency on the radiation pattern of an array antenna

Abstract

A method of performing digital beam forming on the radiation pattern of an array antenna using a plurality of antenna elements, each antenna element being coupled to a signal processing chain. A weighting phase is used in which at least a complex weight coefficient is applied to a digital signal in a corresponding signal processing chain. The digital signal is an intermediate frequency digital signal, and the weighting phase has the following steps: a) duplicating the digital signal into a first and a second digital signal; b) processing the first and second digital signals by multiplying the first and second digital signals respectively by a real and an imaginary part of the complex weight coefficient; applying a Hilbert transform to that signal which is multiplied by the imaginary part of the complex weight coefficient; and c) combining the processed first and second digital signals into a weighted digital intermediate frequency signal by subtracting the second signal from the first signal.

Claims18

Dependent claims

A method of performing digital beam forming on the radiation pattern of an array antenna comprising a plurality of antenna elements, each antenna element being coupled to a signal processing chain, comprising a weighting phase in which at least a complex weight coefficient is applied to a digital signal in a corresponding signal processing chain, said digital signal being an intermediate frequency digital signal, and said weighting phase comprising the following steps:

a) duplicating said digital signal into a first and a second digital signal;
b) processing said first and second digital signals by:
multiplying said first and second digital signals respectively by a real and an imaginary part of said complex weight coefficient;
applying a Hilbert transform to that signal which is multiplied by the imaginary part of said complex weight coefficient;
and
c) combining said processed first and second digital signals into a weighted digital intermediate frequency signal by subtracting said second signal from said first signal.

3 more elements

A system for performing digital beam forming on the radiation pattern of an array antenna, said array antenna comprising a plurality of antenna elements, each antenna element being adapted for coupling to a signal processing chain suitable for applying to a digital signal at least a corresponding complex weight coefficient, said digital signal being an intermediate frequency digital signal comprising:

a first signal processing sub-chain operating on said intermediate frequency digital signal comprising a first multiplier for multiplying said intermediate frequency digital signal by a real part of said complex weight coefficient;
a second signal processing sub-chain operating in parallel with said first signal processing subchain on said intermediate frequency digital signal, comprising:
a Hilbert transform block for applying a Hilbert transform to said intermediate frequency digital signal;
a second multiplier for multiplying said intermediate frequency digital signal by an imaginary part of said complex weight coefficient, said Hilbert transform block and said second multiplier operating in cascade on said intermediate frequency digital signal;
and
a subtracter for subtracting the signal processed by said second signal processing sub-chain from the signal processed by said first signal processing sub-chain, thus obtaining a weighted digital intermediate frequency signal.

3 more elements

Dependencies are inferred from the claim text.

Method and system for performing digital beam forming at intermediate frequency on the radiation pattern of an array antenna

Life of this patent

Method and system for performing digital beam forming at intermediate frequency on the radiation pattern of an array antenna

Life of this patent

Abstract

Claims18