THE CONTROL AND ULTILIZATION OF DUAL ORTHOGONAL MODES IN A RECTANGULAR CAVITY Weigan Lin* and Zhiqing Zhang* ABSTRACT We here calculate the discontinuity impedance of the aperture with metallic grid. bars to set up the complete equivalent circuit of the cavity resonator with a symmetrical aperture lined with metallic grid bars, the two orthogonal modes inside the cavity are excited so that one

TEST OF MONOLITHIC MICROWAVE INTEGRATED CIRCUITS WITH RADIATING PROBES M. HELlER, J.Ch. BOLOMEY* ABSTRACT The principle of local electric field measurements on microwave integrated circuits with radiating probes is described. The main conclusions of the numerical modeling of the probes are discussed. Experimental methods and results of measurement on models and on a monolithic integrated

AN IMPROVED METHOD FOR TYPE FOR RF- AND MICROWAVE-CABLE TESTING. STRUCTURAL RETURN LOSS MEASUREMENT C. Staeger* ABSTRACT A rf-cab1e structural return loss test set-up is described, which bases on a modified transmission measurement circuit. The measuring accuracy is, compared with conventional methods, much higher, because no cable connectors and no directive devices with their inherent e

ACCURACY IMPROVEMENTS IN POWER MEASUREMENTS P. McAllister ABSTRACT The paper and calibration determintation improvement in details the accuracy improvements in both instrumentation of power sensor errors. New measurement methods for of calibration factor will be described which gives uncertainty over current methods. better accuracy and high stability with New instrumentation giving temperatu

PROTECTION SWITCHING FOR DIGITAL RADIO LINKS A.Berndt + ABSTRACT Digital radio link systems need auxiliary equipment to ensure protection against signal quality deterioration due to multipath propagation and equipment failures. In the past, basing on experience with analogue transmission systems, multiline switching arrangements with one protection channel for a few regular channels have bee

PREDICTION OF 1HE RAIN DEPOLARIZATION STATISTICS FOR A MICROWAVE RADIO LINK J.D. Karlellopoulos and A. Serras* ABSTRACT Prediction of the depolarization statistics is studied here using the gamma formulation for the rainrate statistics as well as a special spatial rainrate profile. Numerical results concerning various microwave links sited in U.S.A. are also given. 

DESIGN AND REALIZATION SYSTEM FAMILY Josef A. Nossek OF A 16 QAM-MODEM FOR A 140 Mb/s DIGITAL RADIO and Hermann Barth* ABSTRACT A 16 QAM-modem for 140 Mb/s radio systems is described, with which a spectral efficiency of 3.5 bit/s/Hz is achieved. In the digital signal processing parts extensive use is made of ECL gate arrays. Spectrum shaping according to Nyquist's criterion is performed in t

THE DESIGN OF A LOW COST 2 GHz FOR ANALOG RADIO SYSTEM LOW NOISE DOWNCONvERTER XUYEN DINH, JAMES S. HARRISON, PHILIP T. CHEN & TAO CHOW ABSTRACT A low cost downconverter for a 1.7-2.3 GHz analog radio system has been implemented using the fiberglass printed-circuitry technique~ A maximum 1.9dB SSB noise figure and minimum 31dB conversion gain were achieved. The design and performance of such a

PLANNING RELAY Wolfgang CONSIDERATIONS FOR HIGH CAPACITY DIGITAL RADIO NETWORKS Noack* ABSTRACT ~ The paper deals with path and network design, considering the effects of multipath fading. A multipath propagation model is used, based on measurements of a 59 km path near Munich and on results reported in the literature. The impact of a simulated 2- and 3-path fading on the residual plitude

HIGH USING LINEARITY 16 QAM MICROWAVE POWER AMPLIFIERS FOR DIGITAL RADIO RELAY SYSTEMS R. Michelfeit and H.-J. Thaler* ABSTRACT An experimental characterization of state of the art microwave power amplifiers for high capacity 16 QAM digital radio systems is given. The effects of amplifier nonlinearities on 16 QAM signals are qualitatively demonstrated with the aid of real time signal s