# Tag Info

2

One thing to consider when implementing an IIR filter, whatever the order, is quantization and limit cycles. Let me show you with a quick example with your original filter $y[n] = a*x[n]+(1-a)*y[n-1]$ Let a = 0.005 and say that we use 16-bit signed coefficients. $a_{fixedpoint} = a * 32768 = 164$ Let's assume that the input and output are 16-bit ...

2

In particular, is the fixed point design more challenging for smaller a or larger a ? Smaller is worse: the closer $a$ gets to $0$, the closer the pol movess to the unit circle and the more time domain ringing you have. What are the main design considerations to think about ? A first order low-pass IIR filter is relatively benign. The sum absolute sum ...

1

It used to be that multiplication was a lot more expensive than addition or bitwise operations. For integer (and fixed point) implementation, this can be taken exploited like this: When $a=1/2$ an extremely efficient implementation can be made with a single add and a single shift. $$y[n] = (x[n] + y[n-1]) >> 1$$ Similarly, fractions with a power ...

1

because even though it has more poles than zeros WRONG. The Z-transform transfer function will always have equal number of poles and zeros. Your poles are at $z = -5/4$ and $z = 1/4$. Zeros are at $z = -1/2$ and $z = \infty$. Since ROC will always be concentric circle region without including poles, there are 3 possible ROC for the given transfer function. \$...

0

Only the transfer function in z-transform never gives the stability of the system because multiple systems with the same z transform can have different ROC. So you need additional information about the signal like is it causal, non-causal, stable etc. You can have multiple ROCs here.

0

Given this is a filter and not an oscillator the correct answer is $$H(s) = K\frac{s+2\pi15e9}{(s+2\pi20e9)(s+2\pi20e9)}$$ unless further clarification is given that there are complex poles. When poles and zeros are described to be at a particular frequency in Hz in relation to a filter implementation, it is actually describing a system with a real ...

Top 50 recent answers are included