A PRACTICAL THEORY FOR DIELECTRIC IMAGE ANTENNAS LOADED BY PERIODIC METAL STRIPS M. Guglielmi * and A.A. Oliner * ABSTRACT GIDDE LEAKY-WAVE The dispersion behavior of metal-strip-loaded dielectric image guide leaky-wave antennas is carefully analyzed and completely characterized. Many measurements have been made on this antenna type but until now no direct practical theory was available from wh

SCATTERING MILLIMETRIC BY DIPOLES LEAKY WAVE IN INSET ANTENNAS DIELECTRIC GUIDE AND APPLICATION TO T. Rozzi and L. Ma* ABSTRACT Inset Dielectric Guide most of its advantages is possible to realise polarization properties interface. (IDG) is an alternative to Image Line retaining without its main disadvantages. In particular, it in IDG, low-cost leaky wave antennas with very pure by laying

A MODEL FOR THE PREDICTION APPLIED TO EARTH-SPACE-PATHS. J.D. Kanellopoulos and S.G. OF THE ADVANTAGE OF TRIPLE SITE DIVERSITY Koukoulas* ABSTRACT In heavy rain climatic regionss attenuation caused by rain presents a great problem for satellite communications at frequencies above 10 GHz. In some severe casess double site diversity protection can be proved to be inadequate and consequently tri

COMPARISON BETWEEN SOME OUTAGE PREDICTION FOR MICROWAVE DIGITAL RADIO Umberto ABSTRACT Casiraghi* METHODS - Umberto Mengali** This paper compares some methods for predicting the outage time of microwave digital links. The first is based on a statistical channel model proposed by Rummler [1]-[2]. This is probably the most popular and is often referred to in the North American literature. The s

STUDIES OF MULTI PATH PROPAGATION ON A MICROWAVE LINE-OF-SIGHT LINK K.H.Craig and G.R.Kennedy * ABSTRACT Results of an 18 GHz line-of-sight multipath experiment are presented. Airborne and ground based measurements of the meteorology during one event have revealed strong vertical and horizontal refractivity gradients due to ground based layering. Ray tracing has shown this event to be a n

INFLUENCE OF REFRACTIVE INDEX FLUCTUATIONS ON COMMUNICATIONS SYSTEMS D. VANHOENACKER, A. VANDER VORST * ABSTRACT A model has been developed to calculate the effect of turbulences on a satellite-earth link at centimeter and millimeter wavelength. The present paper investigates the effects upon the group delay in a 0.1-50 GHz frequency band. Preliminary results show a quite intricate effect o

THE CROW'S-NEST ANTENNA - SPECIAL ASPECTS AND RESULTS Helmut Wilden and Joachim Ender* ABSTRACT A phased array with the elements statistically distributed within the volume of a sphere is described ("crow's-nest antenna") which permits a full hemispherical beam coverage. Theoretical calculations concerning radiation pattern, peak and mean sidelobe level, coupling effects and the influence of an el

RADIATION CHARACTERISTICS OF A SAR ANTENNA PANEL OF ERS-1 DETERMINED FROM PLANAR NEAR-FIELD MEASUREMENTS. K. van It Klooster * ABSTRACT Planar near-field measurements were carried out on a single panel of the engineering model (EM) of the Synthetic Aperture Radar (SAR) antenna of the European Remote Sensing satellite ERS-1. The radiation behaviour was determined before and after exposure of th

SPACECRAFT ANTENNA DESIGN USING OPTIMISATION R.C. Brown, P.J.B. Clarricoats and H. Zhou* ABSTRACT The design of shaped-beam antennas suitable for satellite broadcasting and satellite communication is described. The method employs an optimisation search routine in which the reflector shape is varied and the antenna far-field is compared at sample points to the desired far-field. Three exampl

A RECONFIGURABLE SATELLITE ANTENNA DOMESTIC COMMUNICATIONS S. Badessi, V. Costabile +, G.A.E. Crone ++ SYSTEM FOR REGIONAL IN AFRICA *, R. Jorgensen **, AND F. Rispoli, J.M. Montero ABSTRACT An antenna communication system is proposed for a C-band African satellite (AFSAT). The design consists of a pair of TX and RX antennas (4/6 GHz) , base d on dep 1oyab 1e dual gridded reflectors