MESFET and TEGFET equivalent drain and gate bias voltages. dispersions on the characteristics circuit models are given as a function of the The models are prepared to include of one wafer or from wafer to wafer. Two GaAs MESFETs having 1um and 0.5 pm gate llngths are treated. An examp1e is given for a full amplifier and an 0.5µm TEGFET study. 

An S-band image rejection receiver front-end has been designed, using GaAs MMICs to provide all the necessary functions up to, and including, the mixers. The receiver system incorporates the following GaAs MMICs: lownoise amplifier, in-phase signal splitter, quadrature local oscillator splitter, passive routing chip and dual-channel mixer. The mixer chip is novel in that a single-gate FET is used

At the end of the century, Europe will realise rendez-vous between satellites in space. Basi studies have al c ready started at CNES (Centre National d'Etudes Spatiales). A breadboard model of a radar which provides the necessary information during an automatic docking manoeuver is presented. This FM-CW, Ka band radar will be located on the arm extremity of a robotised hunting satellite. The main

A new method for the passive enhancement of very short radar pulses is presented. The design consists of a waveguide resonator fed by a CW oscillator and terminated by a PIN switch that discharges the resonator within 700 ps. An analysis of the resonator model verified by experimental results demonstrates that the gain in output peak power of the coherent pulse amounts up to 7 dB. The principle of

Described in this paper is the practical implementation of a switching speed measurement system for frequency agile synthesizers. The theory of the measurement system is described thus allowing potential users to tailor the system to specific requirements. 

The 30 GHz low noise receivers to be used on board of the Italian Communication satellite IT ALSA T are presently under development and represent a challenging design in the field of on board front ends. This paper describes the design tradeoffs and gives details of the techniques employed. Preliminary test results are also presented. 

Specific attenuation values from 1 to 1000 GH z are calculated by using the negative exponential, Best and Weibull raindrop-size distributions. It is shown that the Weibull distribution is a useful tool for rain attenuation calculations of centimeter, mitlimeter submillimeter radio waves. The empirical relation A=aR between specific attenuation A and the rainfall rate R is also tabulated these th

Amplitude scintillations in a low elevation link from SIRIO satellite are discussed. Examples of power spectra obtained during calm summer nights, clear sky noons and in presence of clouds are shown. Selected noon spectra have been compared to radiosoundigs and known model of turbulence has been found appropriate to describe the spectra, if some simple assumptions are made. A method for estimating

A novel approach to achieve optimum performance from a radial wave power combiner has been developed. The design is based upon traditional matching filter synthesis techniques employed to realize octave bandwidth performance in the form of a radial wave matching filter. A radial wave power combiner which covers 720 to 1770 MHzbetween 0.1 dB points with less than 0.3 dB insertion loss has been deve

New bandpass filters (BPF) using dielectric resonators (DR) were developed, incorporating new circuit technology to improve notably the spurious response, whose existence had been looked upon as a bottleneck in designing the DR BPFs. The newly developed DR BPFs have been used in NEC microwave radio equipment for overseas and domestic applications for their outstanding features-reduction in the ins