Page 312 - Complete Wireless Design

Filter Design

Filter Design 311

Always select high-Q inductors for any RF filter, but especially for these
tunable varieties, to decrease any large variations in insertion loss over fre-
quency. Since the filter as designed with software for the initial basic coupled
capacitive filter of Fig. 6.57 will permit the choice of the tank inductor’s val-
ue, select as low an inductance as the program allows. This is in order to
decrease the filter’s size and cost, and to increase the Q and the performance
of the final design.

Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.