MMIC broadband analog phase shifter and gain circuit for frequency-tunablemicrowave planar multipole active filter categories

In this paper, a lossless variable gain and analog transmission type phase shifter which consists of MESFET with series resonant impedances including varactor diodes is designed. The layout, simulated and measured results of the MMIC chip are presented. The final function of this original monolithic circuit is to be introduced in ring resonator multipole planar filters to tune the frequency response and to compensate for the intrinsic losses of t he resonators. The frequency tunability of these new selective active filte rs is better than one octave bandwidth. As also shown, these phase shifters can be used for the design of a recursive and transversal structure. (C) J ohn Wiley & Sons, Inc.