MICROWAVE SUBHARMONIC IMAGE REJECTION MIXER P. Bonato (*) ABSTRACT Microwave subharmonic image rejection mixer enables to obtain single side band conversion with the use of halved local oscillator frequency. Main features consists of single 3 dB microwave quadrature coupler and suitable duplexer filiters. Antiparallel GaAs schottky diodes have been employed. Frequency conversion exhibits, in t

A SELF OSCILLATING QWITT DIODE MIXER A. Mortazawi, V.P. Kesan, D.P. Neikirk, and T. Itoh* ABSTRACf A waveguide and planar self oscillating mixer using the Quantum Well Injection Transit Time (QWITT) diode have been tested at X-band. The waveguide mixer circuit can either be tuned to have a narrow band conversion gain of about 10 dB or broad band conversion loss of 4 dB. The planar mixer cir

A COMPACT WIDEBAND Ku-BAND LINEARIZER FOR SATELLITE TRANSMIT AMPLIFIERS A. M. Khilla, J. Schaufler, D. Leucht, A. Born ABSTRACT The results of an ESA program to develop and fiable solid-state linearizer, including control are presented. Not only the microwave performance producibility, reliability, and flexibility with are taken into account in the linearizer design. of linearizing travell

COMMUNICATION ANTENNA SUBSYSTEM FOR THE CHINESE SATELLITE DFH.3 W. Chang, E. Dudok, N. Nathrath, E. Sommer * G. Crone ** ABSTRACT The development of a C-Band contoured beam antenna for the coverage of the People's Republic of China is described. The antenna applies two polarisation sensitive reflector shells which are mounted behind each other. The orthogonally gridded reflectos of 2 m diam

Parallel Type Modulator Technology for QPSK and SQPSK Modulation in Advanced M. Spinnler, M. Alberty, ANT Telecommunication G. Ohm ABSTRACT Design and hardware realisation of a parallel type QPSK/SQPSK modulator for a center frequency of 15 GHz and a bit rate of 300 Mbit/sec is described. Analytical expressions and calculations with respect to static phase and magnitude accuracy for the ch

A QUADRUPLE-MODE CONTIGUOUS-BAND MULTIPLEXER FOR COMMUNICATIONS SATELLITES R. R. Bonetti* and A. E. Williams* ABSTRACT A new type of Ku-band, contiguous-band multiplexer with quadruple-mode degeneracies was designed, manufactured, and tested. Extensive tradeoff studies comparing a conventional multiplexer with the present design in terms of system performance were conducted. This paper summariz

A Diqitally Controlled 1unabl~.Hi9b Power Output Filter For Space Apllications. M.A.Kunes G.G. Connor 1 ABSTRACT Practical results are given for a high power tunable filter operating at 12 GHz and having a tuning range of over 200 MHz. Measurements of the spurious mode performance of 3 different configurations of the filter for application in a hybrid coupled output multiplexer are presented.

IMPEDANCE DOUBLE METHOD DIELECTRIC SIMPLIFIES RESONATOR THE (DDR) ANALYSIS OF Philip L. Mambo, Surinder Kumar and Arun Bhattacharyya'" ABSTRACT A Double Dielectric Resonator (DDR) is used to obtain a wider frequency tuning range than a single resonator, with minimum reduction in the quality factor (Q). This paper presents a simple procedure for calculating the resonant frequency and th

Investigations on Air Bridges Used for MMICs in CPW Technique N. H. L. Koster, S. KoBlowski, R. Bertenburg, S. Heinen, and I. Wolff Abstract Two principle types of air bridge realizations are distinguished. The different electrical behaviour of both types is pointed out. Measurements indicate significant losses and phase shifting. A variety of modifications of each type is built on GaAs substrate

CHARACTERIZATION OF THE COPLANAR WAVEGUIDE STEP DISCONTINUITY USING RESONANCE METHOD* Chih- W en Kuo and Tatsuo Itoh t Abstract THE TRANSVERSE Characterization of the step discontinuity of a coplanar waveguide (CPW) is obtained by applying the transverse resonance technique. Resonant frequencies of the structure are calculated by the full-wave electromagnetic fields analysis. With the resona