Patent ID: 7501807

Claim:
A resolution filter for a spectrum analyser, wherein the resolution filter has the following complex, discrete impulse response h used (k): h used ( k ) =C 1 ·[e −C 2 T a 2 ·k 2 *h allp ( t )]· e −jC 3 (k−k 0 ) 2 ·T a 2 wherein C 1 , C 2 and C 3 are constants, k is the sampling index and T a is the sampling period, wherein h allp (t) is the Fourier retransform of e jφ(f) , in which φ(f) is a randomly-specified phase response dependent upon the frequency of the transmission function of the resolution filter, wherein k 0 is a free variation parameter and wherein the variation parameter k 0 is set in such a manner that the frequency overshoot determined by the group delay of the resolution filter is compensated.