An intermodulation feedback circuit for linearization of converter is reported. Design problems are discussed. The performed with a J-band varactor upconverter yielding 3 W 6.8 GHz. The linearization is 12 dB in a frequency band of a SSB power upexperiments are output power at 20 MHz. 

S-band phase modulator for a digital microwave link utilisation has been developped using DGFETs and appropriate CADtechniques. Obtained performances, 35 dB carrier rejection and good linearity demonstrate the feasibility of direct modulation with transmission gain possibility. Design is made on view of monolithic integration on a single GaAs FET substrate. 

Multiturn rectangular spiral inductors in GaAs MMICs have been characterised theoretically and experimentally. The theoretical description developed is suited for layout-oriented CAD. It uses a rigorous multi strip analysis for the spiral substructures combined with a network approach and corrections for three-dimensional effects. Good agreement is obtained with corresponding broadband S-parameter

A new theoret ica 1 approach has been developed to analyze and des ign a double balanced mixer using FETs. A brief description of the theoretical analysis will be given together with some examples of mixer circuits analyz ed by th is method. 

A monolithic SPDT GaAs FET switch covering DC to 4 GHz has been developed with RF performance comparable to high performance PIN diode designs. Insertion loss of 0.8 dB from DC to 4GHz and isolation of 35 dB at 1.5GHz have been achieved. The MMIC incorporates four 1x1200um FETs in a series-shunt configuration with airbridge interconnects on a chip with overall size of 0.6x0.6mm. 



The paper describes a complete design procedure for a monolithic microwave VCO. The procedure includes a computer simulation of the nonlinear active circuit. Practical implementation of the designed circuit and measured results are given. 

Dual- and single-stage low-noise GaAs MESFET monolithic amplifiers based on layers grown using molecular beam epitaxy (MBE) have been successfully developed for use at X-band. The single-stage amplifier exhibits a noise figure of 2.5 dB and an associated gain of 8.0 dB at 12.0 GHz, with power gain increasing to 9.5 dB at a higher bias level. The dual-stage amplifier exhibits a noise figure of 2.7

A novel method for characterizing the surface resistance of two conducting plates shorted at both ends of a dielectric resonator is given in this paper. It utilizes only one dielectric resonator that can resonate wi th both TE012 and TE021 mode at same frequency . The theoretical . relations and experimental results are also given. The described method has been proved to be convenient, relatively

High-power laser radiation has been used for heating ceramic samples in order to make measurements of their dielectric properties at temperatures ranging from the ambient to the destruction temperature. Considerations about the required specifications are discussed. A Ka-band microwave bridge using a single-sideband suppressed carrier signal as reference is described. A carrier modulated by ferrit