Editorial

Circuit simulation programs are already accepted as indispensable efficient supplements to traditional breadboarding, which, moreover, in many instances afford more insight and flexibility. Sensitivity and optimization are beginning to make significant inroads as well, already impacting many realistic design problems. Filter design and layout appear to be almost entirely dependent on the computer. These five areas are discussed in detail in five review papers written by the associate guest editors, D.O. Pederson, S.R. Parker, S.W. Director, G. Szentirmai, and C.H. Mays. The associate guest editors were also responsible for the review of manuscripts in their respective areas. Rapid progress is the watchword; the papers of this issue show where the action in computer-aided design (CAD) of circuits is, or was, by the time it is published. It seems safe to predict that the next technological step will be a blurring of the boundaries between the above mentioned computer-aided circuit design subareas.