Microwave Engineering October 1999 Cover story Our cover shows a field pattern which has been modified using PBG crystals in a novel piece of work at the European Space Agency's ESTEC. The paper is on pages 35 to 43. On the floor Early October is trade show time and this year has proved to be a particularly significant time for trade shows with the second European Microwave Week drawing together more microwave and RF engineers than any previous event in Europe, and the usual mass gathering of the telecommunications industry in Geneva for Telecom 99. Telecom is changing. Four, eight or twelve years ago, the event was dominated by wired and fibre technology. In 1999 it has been dominated by wireless services. Around every corner and in every aisle there turned out to be a microwave link, a satellite service, a microwave cable or antenna. The future certainly looks to be broadband and without wires, if Geneva is anything to go by and that must be great news for our industry. In this issue we also feature some key components for increasing the integration levels for RF integrated circuits. Our In Focus section features some of the new developments in silicon germanium which offer the promise of a technology which is compatible with standard CMOS and yet appropriate for RF devices too, representing the holy grail for the single-chip radio enthusiasts. It turns out that there are more enthusiasts out there than many of us had expected. In a survey at European Microwave Week, in fact the largest ever survey of the views of RF engineers, half of them expected the single-chip radio to be a reality within three years. That is a very significant number and the technologies required for packaging and integration of those components should not be underestimated. Those technologies are, nevertheless, emerging fast and we feature a new inductor structure which has been developed in Korea alongside some important announcements regarding SiGe. We also look one stage further for SiGe. With the photoresist barely dry for the new SiGe parts from Intersil Corporation, the company CEO has announced that he is looking for cheaper processes: high frequency life beyond SiGe. And he is perfectly able to do that because Intersil doesn't have a SiGe fab to keep busy: it uses IBM's fab. None of the three companies which have agreed to use TEMIC's SiGe process do either as they all indulge in some degree of fab-less semiconductor manufacturing. The views on whether a company needs to have a fabrication plant to fabricate semiconductor parts are as diverse as the parts the companies make. Stanford Microdevices is bold in belief that it can do without a fab while Intersil is happy to use outside capacity but still manufactures most of the Si it sells in-house. Whatever the mechanism for getting the parts to market, the parts are impressive. Paul Jackson

Contents In focus SiGe: tomorrow's technology or a passing phase?; A sharper inductor promised for IEDM; Single chip radio within three years say engineers; New On-Line data service Focus on Test & measurement VNAs pack in multiple ports; Optical probe maps MMIC fields; Analyzer speeds spectrum sweep; Real-time analyzers capture 3G burst; Measurement gives lead to PA linearity. A primary national standard millimetric waveguide S-parameter measurement Recent research and development undertaken at the UK's National Physical Laboratory, Teddington, Middlesex, has established a new primary national standard measurement facility for scattering parameters at millimetric wavelengths. Graham French and Nick Ridler describe the new system. PBG crystals: periodic dielectric materials that control EM wave propagation Photonic band gap (PBG) materials are a new class of periodic dielectrics which are the photonic analogues of semiconductors. Peter De Maagt, Ramon Gonzalo and Andrew Reynolds describe how they can be used to control EM wave propagation Close up and overview of the structure of opal. The silica spheres that make up the material are clearly visible. Nonreciprocal 2-port ridge waveguide isolators and phase-shifters An important group of 2-port components is the nonreciprocal class of devices. The purpose of this paper, by Joe Helszajn of Heriot-Watt University, Scotland, is to outline the construction of the classic ferrite resonance isolator and ferrite phase shifter in ridge waveguide. The operation of a 4-port commercial differential phase shift circulator is separately reviewed. Sommaire d'articles Zusammenfassung der Artikel New Products and Data Calendar Classified Catalogue Update & Appointments