ANALYSIS AND DESIGN OF WAVEGUIDE MULTIPLEXERS USING THE FINITE ELEMENT METHOD Andres Gebauer, Felix Hermindez-Gil* ABSTRACT The Finite element Method is used to compute the scattering matrix of waveguide structures with E or H plane discontinuities. This method allows the analysis of bandpass filters and multiplexers in a very flexible way including the effects of waveguide discontinuities as b

AN EXACT FIELDCIRCULATORS CAVITY ANALYSIS WITH OF H- PLANE WAVEGUIDE AND JUNCTION CIRCULAR D. Abstr RADIAL TRANSFORMER Hahn act - Many authors have of dealt with the theoretical Yfor /1,2,4/. circulators. circulators and experimental Exact with more field or investigation theory less For is treatments complicated broadband widely the is is waveguide were material application

AN ADVANCED COMPACT RADIATOR ELEMENT FOR MULTIFEED ANTENNAS * H. Wolf, ABSTRACT * E. Sommer A new compact multimode horn for multifeed application is presented, the principle of operation is described and starting values for a first design iteration are given. Furthermore measurement results of a radiator element with an aperture diameter of 1.7 lambda, fed by a four probe polarizer, are prese

BROADBAND MULTIMODE FEED FOR MONOPULSE TRACKING ANTENNA U Lidvall, M Persson, G Larsson ABSTRACT -------A wide band monopulse feed for use in tracking antennas has been developed. Good performance has been achieved, over a frequency band of more than 15 per cent, in sum as well as difference channels in all planes by the use of multimode techniques. 

REDUCTION OF FORWARD SCATTERINGFROM BLOCKING STRUTS IN REFLECTOR ANTENNAS J.A. Aas* and P.-S. Kildal** ABSTRACT A reduction of forward scattering from struts has been achieved by forming the strut cross section into a rhombic shape and making the surface approximately "hard". Both longitudinally corrugated and strip-coated surfaces are shown to give approximations to the desired boundary con

FEED SCATTERING IN PRIMARY-FED REFLECTOR ANTENNAS Arild Moldsvor and Per-Simon Kildal * ABSTRACT This paper presents a method to improve the calculation of the directivity and the radiation pattern of a primary-fed reflector antenna, by including the contribution due to multiple reflections between the feed and the reflector. These multiple reflections are controlled by introducing a fee

A RECONFIGURABLE P J B Clarricoats, SATELLITE Z Hai, REFLECTOR ANTENNA and G A E Crone+ R C Brown*, G T poulton# ABSTRACT The paper describes a means to change the coverage zone of a spacecraft antenna by reconfiguration of the reflector surface. By using a realistic model for an offset mesh reflector, reconfiguration is successfully demonstrated for the case of two future INTELSAT regional

SHAPED DUAL-OFFSET ANTENNA WITH DIELETRIC CONE FEED * J.R. BERGMANN ABSTRACT A dual offset reflector with a dieletric cone feed is considered. For a chosen main reflector, the subreflector and dieletric surfaces are shaped to obtain a pre-specified phase and power over a plane between the reflectors. The work presents a formulation for the synthesis of this system based on GO assumption. 

A MONOLITHIC BROADBAND MICROWAVE DOWN CONVERTOR and E. CONSTANT* S. HEMBERT, E. ALLAMANDO, J.C. VANDEVELDE J. MARCOUX** ABSTRACT This down paper presents convertor. the realization of a GaAs monolithic broadband The originality of this device consists in the use of only two field effect transistors (without d.c. bias for the first stage). As a consequence of the simplicity of our device,

AN L-BAND MONOLITHIC RECEIVER FOR MILITARY APPLICATIONS 1 Sarjit John S. Bayruns Bharj 2 Har Dayal Ron Paradise ABSTRACT An L-Band superhet receiver scheme using Gallium Arsenide Monolithic Microwave Integrated Circuit technique has been developed for cost effective military application. The front end of the receiver comprised of a single pole double throw switch for antenna selection, fo