Microwave Variable Delay Devices

Needs for nondispersive microwave variable delay devices exist in RADAR, communication, ECM, and test systems. Methods which have been investigated to satisfy these needs are reviewed in this paper. Techniques that employ solid-state microwave acoustic interactions and that have promise of satisfying some of the microwave variable delay requirements are described in detail, and their present capabilities and potential capabilities are discussed. One technique employing magnetoelastic waves is particularly promising and the state of the art of this technique is analyzed thoroughly.