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At the Leuven Microwave meeting several interesting articles are presented in a small book. With help and with approval from the authors some of these articles are presented here. The authors have made these articles available on this site to be of use to the whole amateur group also those not able to come to Leuven and not able to buy the book. I want to express my thanks to the authors of the articles. Some more articles will follow. Special thanks to Hans, ON4CDU who has been the drive for the Leuven microwave meeting. I hope many more will follow. AT this moment I have two articles from the microwave meeting from 2001. The first is an article on Noise in satellite links by ON4DSP which is a zipped PDF file. The second is an article on measurements from ON4CDU and ON4CDQ on connectors and many cable's assy's for the microwave bands. This is a very good story on which cables and connectors can be used up to 24 GHz. Because it is a large amount of info I placed it on several pages.
Article on Noise in satellite links from ON4DSP (zipped PDF file; 308 kB) Article on 24 GHz Waveguide filters from ON1BPS Measurements
Hans Wagemans - , ON4CDU and Peter Delmotte - ON4CDQ I. Introduction When building microwave equipment, learning from experience is an important factor. The normal evolution is to start on the lower microwave frequencies and when you are able to develop and build equipment for these you can move on to the "real" microwave frequencies. So when your 10 GHz equipment is finalised, the next natural step is building equipment for 24 GHz. With every step towards higher frequencies, questions arise: is this connector, cable transistor, dummy load, power meter, etc. suitable for this frequency? During the development of our 24 GHz transverter, experience in this field has been gained, and this article tries to share some of it. To document our experience, a measurement session was organized at the K.U.Leuven ESAT-Telemic lab, where measuring equipment up to 50 GHz is available. Measurements were done on a variety of components bought at flea markets in the Netherlands, Belgium and Germany. Most of these cables, connectors etc. are very cheap and originate from GSM base station equipment. It is obvious that the measurement results have to be seen as indications only and cannot be taken as absolute values. It is also possible that components that look the same have been made by another company and behave differently. The intention of this article is to provide the microwave experimenter with some guidance on buying components at flea markets. link to measurements of adapters link to measurements of flexible cables link to measurements of semi rigid cables link to measurements of power sensor link to measurements of attenuator link to measurements of coupler III. Conclusions In general, the use of SMA connectors at 10 and even at 24 GHz is possible. To be avoided are 90 degree bends, either as an L-adapter or as a connector. If you look at manufacturer specifications, the maximum useable frequency of bends is rarely specified. N-Connectors, at least quality ones, can be used up to 18 GHz. A high precision N-connector that is guaranteed up to 26.5 GHz does exist, but is rarely found on flea markets. This type of connector has the advantage of being very rugged and is often found on test equipment. The precision N-type will mate with a standard version.
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