Here is the abstract you requested from the IMAPS_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|The Influence of Substrate Parameters on Millimeter-Wave Planar Circuits|
|Keywords: Substrate Parameters, Millimeter-Wave, Design Consideration|
|The designers of millimetre-wave planar circuits are faced with an increasingly diverse range of substrate materials on which to fabricate single and multilayer circuits. The correct choice of substrate for a particular application at a given frequency is crucial in obtaining an efficient design. In this paper we have obtained new information that compares and analyses the performance of a range of commonly available substrate materials over the frequency range 1 GHz to 80GHz. For the comparison we have considered the key electrical parameters of the substrates, namely the dielectric constant, loss tangent, and thickness, as well as the effects and limitations of the associated fabrication process. The four substrates considered were alumina (with gold conductors), LTCC (with gold conductors), photoimageable thick-film (with silver conductors), and polymer (with copper conductors). In each case we considered the fabrication of a typical microstrip component, namely a patch antenna. For each material we assessed the quality of the fabrication process, the inherent losses, the accuracy with which the component could be designed, and lastly the size of the component. Clearly many of the parameters are interrelated and it is not obvious from a simple inspection of the substrate properties which of the technologies will lead to the most effective design. Graphs have been generated that provide the circuit designer with the information to develop an optimized design, considering both electrical and economic factors. For example, whilst we have shown that new polymer materials yield a higher working bandwidth (3% at 25GHz) than LTCC or alumina, they do so at the cost of increased circuit size, and poorer thermal properties. Clearly the designer needs to rationalise all of these factors to achieve optimum performance, but this information is not available through standard CAD packages, such as ADS, which focus only on the electrical issues.|
|Wesam Ali, Research Student
University of Surrey
Guildford GU2 7XH,