(s) being asymmetric means that it has one zero at W = 0 and three zeros at w = 8. The solid lines plot the values as obtained by evaluating the expressions (4.106)-(4.108), while the marks indicate values as extracted out of Mat- lab/Simulink simulations. The crosses, circles and squares respectively represent the transfer functions H0,1(jw), Ho,o(jw) and H0,2 (jw). Comparing Fig. 4.29(a) and (b) shows that use of an asymmetric filter design indeed improves rejection of the signal content near 200, lowering H0,2(s) with 6 dB. As predicted, this comes at the expense of an increase of Ho,o(s). Note that this improved H0,2(s) requires no extra hardware (the filter order remains unchanged) but only proper placement of the filter zeros. It illustrates the design insights gained by having the expressions (4.106)-(4.108) avail- able. The accuracy of the symbolic models (4.106)-(4.108) was compared to values extracted from numerical simulations. These simulations involved applying a single input tone at respectively fo + fs, fs and 2fo + fs Hz, for fs ranging from 200Hz to 1MHz. Analysis of the steady-state output signal then yields the output signal component at baseband (at frequency fs). The result is listed in table 4.3. As can be seen, all symbolic expressions are at least within 2% accurate, with H0,1 (s) even being 0.01% accurate. Fig. 4.30 illustrates how the model accuracy varies with the order of and the number of tones taken into account in computing the input-output HTM. It was plotted for the HTM element ,((s). For other HTM elements, similar results were obtained. Fig. 4.30 shows that, for constant , there is a maximum number of tones beyond which no improvement in accuracy can be obtained by increasing the number of tones taken into account. This is due to the fact that, when limiting the number of terms in the approximation (4.82), effects due to the presence of higher-order tones do not enter the expressions for the HTM elements of interest. A likewise reasoning holds when keeping the number of tones co