The design characteristics of a compact size spiral type antenna, suit
able for satellite mobile communications are determined. Criteria used
in designing the antenna are low profile shape, circular polarization
, optimum radiation pattern for European latitudes and simplicity in c
onstruction. Several experimental results measured on a constructed pr
ototype are shown, exhibiting a satisfactory behaviour of the radiatio
n properties. Some suggestions are also given for further improvement
of the antenna unit.