Recent advances on millimeter wave PCN system development in Europe-an invited survey

The possibility of applying millimeter waves in various areas in the commercial arena has a long history, as the technical advantages being offered by such systems have been known for more than 3 decades. The necessity of turning their attention away from the military sector towards commercial products has forced more and more companies to look at millimeter wave communications very thoroughly. As a matter of fact and fortunately this was accompanied by the advent of low-cost integration procedures, i.e. hybrid- and monolithic-integration technologies, respectively. Having the necessary technology at hand, mature and commercially available, a wide field of employment areas has been opened. From indoor high-speed radio communication systems at 10.6 GHz, as proposed by NTT of Japan, over "gateways" for mobile or new, 'deregulated' stationary telephone systems at 38 and 55 GHz, available from Northern Telecom, UK, and WLANs at 60 GHz, like the MBS project, under research within the European RACE-programme, to the optic microwave hybrid approach for pico-cellular PCNs, as proposed by Alcatel-SEL of Germany and CNET of France, the scope of today's applications is very wide. While the military market is still decreasing, the commercial application of millimeter waves is increasing very rapidly. The actual status and the developing technological trends, as they can be seen from Europe, are surveyed.