05.Filter design and approximation
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104 FILTER DESIGN AND APPROXIMATION
Shunt parallel LC. L2( 2) = .666805E — 09 C2( 2)
=.105229E — 10
Through series LC. L3( 3) = .150777E — 07 C3( 3)
=.465370E — 12
The resulting circuit shown in Fig. 5.11 can be analyzed using the SPICE
template described in Appendix G. The results in Fig. 5.12 show |
that the |
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minimum loss in the pass band is 1.487 dB, which corresponds to |
p |
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H0 |
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0.7101. |
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PROBLEMS
5.1Design a band-pass filter with center frequency 500 MHz, fractional bandwidth w D 5%, and pass band ripple of 0.1 dB. The out-of-band attenuation is to be 10 dB 75 MHz from the band edge. The terminating impedances are each 50 . Using SPICE, plot the return loss (reflection coefficient in dB) and the insertion loss over the pass band.
5.2Design a band-pass filter with center frequency 500 MHz, fractional bandwidth w D 5%, and pass band ripple of 0.1 dB. The out-of-band attenuation is to be 10 dB 75 MHz from the band edge, and it is to transform a 50 source impedance to a 75 load impedance. Using SPICE, plot the return loss (reflection coefficient in dB) and the insertion loss over the pass band.
5.3Design an elliptic function filter with the same specifications as in Problem 5.1, and plot the results using SPICE.
5.4Design a high-pass three-pole Butterworth filter with cutoff frequency of 900 MHz.
REFERENCES
1.W.-K. Chen, Passive and Active Filters, New York: Wiley, 1986.
2.E. A. Guillemin, Synthesis of Passive Networks, New York: Wiley, 1957.
3.F. F. Kuo, Network Analysis and Synthesis, New York: Wiley, 1962.
4.A. Zverev, Handbook of Filter Synthesis, New York: Wiley, 1967.
5.H. Howe, Stripline Circuit Design, Norwood, MA: Artech House, 1974.