A MONOLITHIC C-BAND VARIABLE GAIN AMPLIFIER WITH DIGITAL CONTROL Heinz J. Siweris. Abstract A GaAs monolithic variable gain amplifier based on segmented dual-gate PETs is described. Design, fabrication, and performance of the MMIC are outlined. Special emphasis is given to the modeling of the active devices. It is shown that a simple equivalent circuit is sufficient to accurately model multiple

A Resistive HEMT -Mixer with Very Low LO-Power Requirements Low Intermodulation Herbert Zirath ", Niklas Rorsman .. ABSTRACT and The channel resistance of a High Electron Mobility Transistor (HEMT) is used as a time variable resistor to accomplish frequency mixing. An X-band image rejected mixer was constructed and pseudomorphic HEMTs were fabricated in order to investigate the performance. Acce

A 14 GHz 80 WATT GaAs FET AMPLIFIER P Martin, P J Allen, J B Ness ABSTRACT An 80 W GaAs FET Amplifier for the 14.0 - 14.5 GHz band presented. The amplifier uses a radial waveguide combiner to achieve a 20 way power combination. is divider/ 

A NEW APPROACH TO THE DESIGN OY WIDE-BAND MAGNETOSTATIC OSCILLATORS S V Zagriadski * ABSTRACT WAVE The paper reports a new concept in the design of magnetically tunable multi-octave oscillators employing magnetostatic wave (MSW) delay line filter in the feedback loop of a wideband amplifier. The principle of the compensation of frequency dependent phase shifts in an oscillator circuit is formula

A SIMPLE FREQUENCY SYNTHESIZER CONFIGURATION MICROWAVE RADIO LINKS FOR LOW CAPACITY DIGITAL G Kolumban ABSTRACT + A new low cost frequency synthesizer configuration has been developed for a low-capacity digital microwave radio equipment. The key element of the proposed synthesizer configuration is a double sampling SPLL circuit. The paper gives the exact model of the double sampling SPLL, de

QUASI PINCH-OFF GaAs FET LINEARIZER FOR MICROWAVE SSPAs C. Buoli* L.A. Cervi* A. Abbiati* ABSTRACT A new microwave linearizer is hereafter presented. The linearization exploits the principle that in a GaAs FET device biased near the pinch-off region the drain current and the power gain grow when the input power increases (AM/AM compensation). At the same time, placing a bias resistance on the

Inhibition of the nociceptive response of the parafascicular nucleus, due to microwave irradiation on spinal cord in rabbits Jian TENG, Hongqu YAN, Danielle VANHOENACKER, Andre VANDER VORST* Abstract The parafascicular nucleus plays an important role in the harmonization process of the pain sensation. The experiment described below consists in using electric impulses to stimulate the superficial

A MULTI-CHANNEL GENERATOR AT 433 MHz WITH. ACCURATE AMPLITUDE AND PHASE CONTROL APPLICATION L. Martens* and C. De Wagter** FOR HYPERTHERMIA *Laboratory of Electromagnetism and Acoustics, University of Gent, Sint-Pietersnieuwstraat 41, B-9000 Gent, Belgium **Department of Radiotherapy and Nuclear Medicine, University Hospital of Gent, De Pintelaan 185, B-9000 Gent, Belgium AB.SIRAcr A new gene

INTERSTITIAL ENDFIRE APPLICATORS: ANALYSIS AND EXPERIMENTAL RESULTS G. Cerri*, R. De Leo*, V. Mariani Primiani* ABSTRACT Several coaxial terminations to be used as endfire thermic applicators have been tested experimentally. A mathematical model for the most appropriate one has been set-up obtaining a good agreement with experimental results. 

CUTOFF WAVEGUIDE Jan vrba*, Montecchia+, APPLICATORS FOR HYPERTHERMIA CANCER TREATMENT Francesco Cafiero Franconi+, Miroslav Lapeso, Alexander Kobranovo, Jiri CervenyO, Italo Vanucci+ ABSTRACT The basic theory and the development of evanescent mode waveguide hyperthermia applicators is described. Distributions of specific absorption rates (SAR) on phantoms are presented and discussed. Ori