VHF / UHF Filters and Multicouplers: Application of Air Resonators

Introduction

We can find on the roofs of certain office buildings veritable forests of antennas, sometimes so close to each other that we could ask ourselves how they can fulfill their role properly. We should not forget, in effect, that the radiation pattern of an antenna is plotted on specialized sites, with sufficient ground extension and generally outside cities, where the nearby conductive objects that are disruptive to propagation are carefully avoided. This means that the operating conditions, which are always different from the measuring ones, mean an antenna almost never radiates in the expected way. Hence the necessity, in order to try to remedy this proliferation at a time when public space has become a gigantic telephone cabin, of possessing weapons that allow us to fight against this phenomenon related to the development of modern telecommunication. One of these weapons is multicoupling.

Multicoupling is the group of techniques that allow us to connect several transmitters or several receivers, or often both, to the same aerial. It is thus an activity that concerns anything that puts a radio link in operation, in the most generic sense of the term: broadcast, radiotelephone, frequency modulation, DAB, military radiocommunications, satellite links, etc. It is present in network infrastructure and is consequently a technology and an activity reserved for professionals and completely ignored by the general public. On the other hand, all radio engineers, as well as all ...