As frequencies rise in MMIC or high frequency design ( board or chip) lumped elements cannot be used for implementing filters. In this case a technique that is useful is the use of transmission line stubs. The use of these stubs leads to microwave filters which are practical (with a few constraints). These types of filters and the methods of implementation are discussed in a recent release of a technical memorandum by the Techteam at Signal Processing Group Inc. Interested readers may access this article at http://www.signalpro.biz , in the “Engineer’s Corner”.