Hello folks,
I was just wondering whether a Finite Impulse Response system exists
in a continuous time system.Could anyone throw some light upon this
topic?
Sincerely
yours,
Saptarshi.....The newest member of this group...
FIR and IIR systems
Started by ●January 29, 2008
Reply by ●January 29, 20082008-01-29
On 29 Jan, 14:28, "saptarshi....@gmail.com" <saptarshi....@gmail.com> wrote:> Hello folks, > �I was just wondering whether a Finite Impulse Response system exists > in a continuous time system.No, they don't. If I recall correctly there exists some theorem in control theory which states that the order of the numerator in a continuous-time system can be no larger than the denominator. Rune
Reply by ●January 29, 20082008-01-29
Rune Allnor wrote:> On 29 Jan, 14:28, "saptarshi....@gmail.com" <saptarshi....@gmail.com> > wrote: > > > Hello folks, > > �I was just wondering whether a Finite Impulse Response system exists > > in a continuous time system. > > No, they don't.Of course they do. A simple example is the averaging filter, which often occurs in sampling processes: h(t) = 1, 0<= t <= T = 0, else. Regards, Andor
Reply by ●January 29, 20082008-01-29
On 29 Jan, 14:57, Andor <andor.bari...@gmail.com> wrote:> Rune Allnor wrote: > > On 29 Jan, 14:28, "saptarshi....@gmail.com" <saptarshi....@gmail.com> > > wrote: > > > > Hello folks, > > > �I was just wondering whether a Finite Impulse Response system exists > > > in a continuous time system. > > > No, they don't. > > Of course they do. A simple example is the averaging filter, which > often occurs in sampling processes: > > h(t) = 1, 0<= t <= T > � � �= 0, else.Is that a *physical* process? Some might say that this is an 'sufficiently accurate' idealized representation of an imperfect sampling system. They might even support that claim by referring to the fact that sample-and-hold systems contain some sort of capacitors. Which, IIRC, are represented as exponential functions, not constants... Rune
Reply by ●January 29, 20082008-01-29
On Jan 29, 8:28�am, "saptarshi....@gmail.com" <saptarshi....@gmail.com> wrote:> Hello folks, > �I was just wondering whether a Finite Impulse Response system exists > in a continuous time system.Could anyone throw some light upon this > topic? > � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � Sincerely > yours, > > Saptarshi.....The newest member of this group...Yes, a SAW filter is a continuous time FIR filter. Mark
Reply by ●January 29, 20082008-01-29
On 29 Jan, 15:08, Mark <makol...@yahoo.com> wrote:> On Jan 29, 8:28�am, "saptarshi....@gmail.com" > > <saptarshi....@gmail.com> wrote: > > Hello folks, > > �I was just wondering whether a Finite Impulse Response system exists > > in a continuous time system.Could anyone throw some light upon this > > topic? > > � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � Sincerely > > yours, > > > Saptarshi.....The newest member of this group... > > Yes, �a SAW filter is a continuous time FIR filter.I spent some 6 years working with acoustic surface waves. Those were weird beasts what most properties were concerned, but I can't remember them having any properties like FIR? Rune
Reply by ●January 29, 20082008-01-29
On Jan 29, 8:28�am, "saptarshi....@gmail.com" <saptarshi....@gmail.com> wrote:> �I was just wondering whether a Finite Impulse Response system exists > in a continuous time system.Analog transversal filter. Uses tapped delay lines.
Reply by ●January 29, 20082008-01-29
On 29 Jan, 15:19, Greg Berchin <gberc...@sentientscience.com> wrote:> On Jan 29, 8:28�am, "saptarshi....@gmail.com" > > <saptarshi....@gmail.com> wrote: > > �I was just wondering whether a Finite Impulse Response system exists > > in a continuous time system. > > Analog transversal filter. �Uses tapped delay lines.Can you show that these have Finite Impulse Responses? I would imagine that these devices would have to be modeled as a network of RLC transmission lines, right? Which, IIRC, behave like IIR systems? Rune
Reply by ●January 29, 20082008-01-29
On Jan 29, 9:24�am, Rune Allnor <all...@tele.ntnu.no> wrote:> > Analog transversal filter. �Uses tapped delay lines. > > Can you show that these have Finite Impulse Responses? > I would imagine that these devices would have to be > modeled as a network of RLC transmission lines, right? > Which, IIRC, behave like IIR systems?Difference between theory and practice? In theory, for an ideal tapped delay, y(t) = b0*x(t) + b1*x(t-t1) + ... + bn*x(t-tn) which has a finite impulse response. In practice, if the tapped delay line is implemented as a "network of RLC transmission lines", then of course the characteristics of the transmission line enter the picture. I cannot comment any further, having never personally worked with them. Greg
Reply by ●January 29, 20082008-01-29
Rune Allnor wrote:>>Hello folks, >> I was just wondering whether a Finite Impulse Response system exists >>in a continuous time system. > > > No, they don't. > > If I recall correctly there exists some theorem in control theory > which states that the order of the numerator in a continuous-time > system can be no larger than the denominator.This applies for the lumped networks only. You can have the analog FIR using the system with the distributed parameters, such as a transmission line. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
