Microwave Engineering February 1999 Cover story Our Focus in this issue is on passive components. The cover reflects the current drive to get more and more passive components on-chip as a means to reduce component count and achieve further integration. Background photograph - 6pm Bude, Cornwall - by Joanna Rice. From "One Day For Life" published by Transworld Publishers Ltd for SEARCH'88 Vying and buying Just how big does a company need to be if it is to compete successfully in the world economy? Judging by the acquisition and cooperation announcements of the last few weeks, there are plenty of organisations who think they need to be bigger. We've now got Daimler-Chrysler with a new group that covers aerospace, automotive and plenty of core technology in a truly global merger. Back in Europe, the famous Marconi name is leaving the GEC home and heading for British Aerospace following rumours of many other potential suitors. What set us thinking about these issues just this week was an announcement by IFR, which bought the former Marconi Instruments company last year without the Marconi name, that it will in future be selling the Gigatronics test and measurement line throughout Europe and actually pretty much everywhere outside North America and one or two countries in Asia. Now this isn't a merger: an IFR spokesperson confirmed that there would not be any exchange or purchase of stock. But it is indicative of the continuing consolidation of the test and measurement industry. Will it work? That's a difficult question to answer and depends a lot on the company cultures and the individuals concerned. It does follow a bunch of alliances in the T&M world, including Tektronix, Advantest and Rohde & Schwarz. There have been some obvious outputs from that alliance, including CDMA testers derived by Tektronix from a Rohde & Schwarz platform but not many other similar examples of cooperation spring to mind. Then there are the mergers or takeovers like Anritsu and the former Wiltron where the approach has been, over a period of time, to develop a single strong brand. There's also another approach back in the shadowy area where instrumentation software resides. At a recent product launch for mobile telecom test solutions a senior manager from Hewlett Packard talked about "100s" of external software developers working on instruments. With the telecoms industry itself being so software dominated, the revelation might not come as a great surprise but it does show just how useful "alliances" can be, whatever the size of company. HP did also mention one company that it had been working with to develop a GSM base-station tester, by name. That name? Ericsson. In this issue we are featuring semiconductors and passives, both together and apart. We are very pleased to be publishing two specially selected and updated papers from the GAAS '98 conference and particularly pleased to note that one of them is actually by Professor Hans Hartnagel, who will chair this years meeting, GAAS '99. Paul Jackson

Contents In focus Broadband wireless industry creates Study Group; New chambers for Spanish EMC test laboratory; Workshops have 3G theme. Focus on Passive and control components Dividers and diplexers go dual-band; Filters slim down for dual-band, Cable assemblies restrict intermodulation; Tuners step into space applications. RC network use LTCC technique; Absorptive attenuators have accent on IP3; Solenoids give new twist to IC inductors. The cross-guide directional coupler in ridge waveguide A classic microwave component is the cross-guide directional coupler. The purpose of this paper by M.Mckay, R.Robichaud, J.Frena and J.Helszajn is to give some calculations on the coupling and directivity of this structure in ridge waveguide. The four arrangements considered here employ various combinations of single and double ridge waveguides for the primary and secondary sections. In this issue we are pleased to present the first two papers in a series of five selected by the GAAS Association steering committee from the GAAS '98 conference, part of the first European Microwave Week. The two papers reflect the diversity of GaAs circuits, covering mm-wave radio link applications and microsensors for mechanical engineering which can employ wireless transmission of the energy and sensor signals. Compound semiconductor microsensors for applications in mechanical engineering In the first of our featured GAAS '98 papers, the application of compound semiconductor microsensors in mechanical engineering is described. The authors, H.L. Hartnagel, D. Arslan, M. Brandt, A. Dehé, K. Mutamba, A. Vogt, B. Breuer, D. K. Hennecke and B. Stoffel outline concepts for wireless transmission of the sensor signals and energy supply and include a section on microwave power sensors. Modular Millimetre-wave transciever design for today's digital radio link An integrated transceiver design is described which is aimed at digital radio links in wireless local loop systems in the second of our specially selected GAAS '98 papers. The authors are J.P. Viaud, D. Lévy, M. Lajugie, O.Vaudescal , S. Tranchant, P. Quentin, D. Pons, B.Patel and D. Panchal. Sommaire d' articles Zusammenfassung der Artikel New Products and Data Calendar Classified Catalogue Update & Appointments