HOW TO SOLVE YOUR PEDAGOGICAL PROBLEMS IN MICROWAVES. M. Vindevoghel*, M. HOchedez*,J.F. Legier* ABSTRACT We present, in this article, some of the problems often encountered by the students when they start on a microwave course. We bring answers to these problems by means of Computer Assisted Learning and state in the conclusion our observations following an experiment of C.A.L. carried o

CAL AND CAD SOFTWARE FOR MICROWAVE EDUCATION, ENGINEERING AND RELATED APPLICATIONS T I Nikolskaya*, V V Nikolskii** ABSTRACT A program package called "Electromagnetic Waves" in seven parts has been developed. It is intended for computer aided learning (CAL) with widely making use of animated graphics of fields and waves which are simulated during the study. 

FRONT-END TOPOLOGIES FOR PHASED ARRAY RADIOMETRY M. K. Sonmezt, R. J. Trewl and C. P. Hearn2 ABSTRACT There is interest in developing phased array radiometers for space based applications. The limitations and the optimum topology for beam forming networks in radiometric systems, however, are not well understood. In this work, two phased array total power radiometer front end topologies are c

DETECTION OF INTERNAL DEFECTS BY MICROWAVE TIME DELAY SPECTROSCOPY J.I. Agbinyal,l.C. Devlinl, AZ. Tirkel2, C.F. Osbome2 ABSTRACT This paper discusses the detection of buried defects in an aircraft wing section, using microwave transmission time delay spectroscopy. The power spectral densities of adjacent scans,(1.5 cm. apart), are subtracted to enhance defect edges. The results show that test

MULTISPECTRAL RADIOMETRY FOR THE DETERMINATION VEGETATION COVER CONDITIONS. M.MAzANEK*, Z.PECENY*, IJANiK*, T.CESKY**, C.RUMLER *** OF THE ABSTRACT This paper deals with the possibility of multispectral radiometry using to determine local conditions of plants including inverse problems in localization and decomposition of measured data into the physical parameters - e.g. emissivity (noise temper

NEW APPROACH FOR DETERMINING THE COMPLEX DIELECTRIC CONSTANT OF VEGETATION LEAVES S. Trabelsi, M. Ghomi, J.C Peuch, H. Baudrand. ABSTRACT A new approach for modeling the vegetation leaves in the X-band is presented. Here, as an example a corn leaf is considered, where it is assumed to be a superposition of a cylindrical dielectric post and a very thin dielectric sheet. We determine the complex d

A RADIOMETER FOR GROUND-BASED DETECTION OF STRATOSPHERIC OZONE AT 110 GHz Olli Koistinen1~ Heikki Valmu1, Antti Raisanen1 Juhani Talvela , Martti Hallikainen2 ABSTRACT A low noise superheterodyne receiver has been designed and constructed for ground-based monitoring of stratospheric ozone. The receiver measures the ozone spectral line at 110.836 GHz with a total bandwidth of 1.0 GHz. The receiver

MICROWAVE-ACOUSTIC MEASUREMENT PROFILING IN CLOSED ENVIRONMENTS SYSTEM FOR REMOTE TEMPERATURE M. Daas *, R. Knochel * ABSTRACT This paper presents a sounding-system transmitter, consisting of a doppler radar at 10.0 system power which spatial GHz and an acoustic is now reported, and increases the first suffers from time, which uses a travelling reflector. considerably is operated temperatu

VALIDATION OF NONLINEAR BIPOLAR TRANSISTOR MODEL BY SMALL-SIGNAL MEASUREMENTS J. Vidkjrer *, V, porra", J. Zhu**, T. Huttunen** Abstract: A new method for the validity analysis of nonlinear transistor models is presented based on DCand small-signal S-parameter measurements and realistic consideration of the measurement and de-embedding errors and singularities of the small-signalequivalent circuit

PERFORMANCE AND LARGE SIGNAL MODELLING OF A GaAs HETEROJUNCTION BIPOLAR TRANSISTOR MIXER AT 950MHz B A XAVIER & C S AITCHISON BRUNEL UNIVERSITY (UNITED KINGDOM) Abstract A GaAs heterojunction bipolar transistor (HBT) single ended active mixer is discussed. Simulations are performed using a large signal HBT model. A novel way of incorporating the d.c equations of an HBT into a large signal simulat