Microstrip Antennas and Arrays in Communications, Navigation and Radar

Abstract

Nearly half a century ago, the concept of microstrip antennas has been proposed. After a long period of being employed only for special military use, they have now found a broad and still strongly increasing field of applications mainly driven by modern communication and navigation technology. Microstrip antennas are well known for several advantages: They are mainly flat, lightweight and can be produced easily and inexpensively in several technologies suitable for RF circuits. This also offers the possibility to integrate them with active devices even as a part of an MMIC-chip. In this way, very small radiating front ends and smart antenna systems can be built up. For high frequencies beginning with Ku-band, LTCC-technology is often used to build multilayer structures with many layers and active and passive components. Large arrays, including complex networks for beamforming and steering, can be fabricated in PCB-technology either as a single multilayer board or in a modular architecture. If they are printed on a flexible substrate they may conform to a given surface and thus can be integrated seamlessly in an aircraft or any other vehicle to reduce drag and meet aesthetical requirements. This talk will present the fundamental concept of microstrip antennas and discuss some basic methods and guidelines for analysis and design. Several examples for their application will then be given including antenna arrays with dual polarization and special networks for beamforming which are used in synthetic aperture radar as well as narrowband, broadband and multifrequency antennas for advanced navigation receivers employing digital beamforming and array processing to mitigate interferes and multipath signals. In communications, some examples for different microstrip antenna technologies especially for high frequency applications in user terminals of satellite systems will be shown.