Application of MMIC technology and new stability concept for recursive filter design

In this paper, two active filters in the X-band, using low frequency transversal and recursive principles are presented. After some theoretical points, we first present a general design approach for recursive filters in MMIC technology. We then apply these principles to two first-order recursive structures, one with a fixed centre frequency and the other one tunable. Separate study of different functional blocks corresponding to low frequency functions is performed. We will see that the tunable filter can be easily derived from the non-tunableone. Then, we validate our approach with the measured results for these two filters. Finally, we focus on the new stability concepts recently developed by A. Platzker, which we apply to our structures.