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Przedstawiamy opracowanie przyrządów HEMT (High Electron Mobility Transistors) z GaN/AlGaN, a następnie pierwszego w Polsce monolitycznego mikrofalowego układu scalonego, w którym zastosowano przyrządy HEMT z GaN/AlGaN. Opracowanie przyrządów HEMT. Sekwencja warstw epitaksjalnych tworzących strukturę tranzystora była następująca: bufor AlN, kanał GaN, warstwa Schottky’ego AlGaN oraz warstwa podkontaktowa...
The paper describes the results of electromagnetic simulations of the pin-gap effect in six types of coaxial connectors. Two full wave electromagnetic simulators have been used HFSS and QuickWave. The results of simulations and as well as computed field distributions inside structures give deeper insight into the behaviour of coaxial connector junctions. The performance of simulators is also discussed...
We compare performance of the multiline through-reflect-line and the multi-reflect through technique in the calibration of a 220-325 GHz vector-network-analyzer with WR-03 rectangular-waveguide test-ports. Both techniques employ multiple uniform-waveguide sections with unknown propagation constant and different lengths which are used either as two-port or - after terminating with an unknown reflect...
We present results of a source-pull cold-hot on-wafer noise characterization of a FinFET with the gate 60 nm long and 45.6 μm wide. We performed this in the frequency range 0.8 - 8 GHz using the newest instrumentation available at present for measuring both scattering and noise parameters. From the output noise powers measured in frequency, we determined with our own method consisted characteristics...
We study the performance of the multiline through-reflect-line method in the calibration of a 220-325 GHz vector-network-analyzer with WR-03 rectangular-waveguide test-ports. The calibration method is based on multiple uniform-waveguide sections with unknown propagation constant and different lengths, a reflect standard which is assumed to be identical on both vector-network-analyzer ports but otherwise...
We present an extension of the coaxial multiline through-reflect-line calibration method which allows to correct for line length errors and center-conductor-gap variation. Our approach is based on the multi-frequency formulation of the vector-network-analyzer calibration problem which accounts for the physical relationships between calibration standard S-parameters at different frequencies. We illustrate...
Results of an investigation on various microwave absorbing materials developed at the telecommunications research institute (PIT) are presented. The materials, composed of proprietary powders mixed with either classical liquid or modernized dry material bonder, were characterized with a wideband T/R method using 7-mm in-house made coaxial airline holders utilized also for the multiline TRL calibration...
A novel statistical technique for calibrating vector network analyzer (VNA) with zero-length thru and multiple-reflect terminations is presented. The terminations are assumed to be of the same type, e.g. offset terminations of different lengths with partly unknown characteristics. Their reflection coefficients are modeled over frequency and identified in the calibration together with the VNA error...
We present a statistical technique for one-port vector network analyzer (VNA) calibration based on multiple reflect and a single reference standards. The multiple reflect standards are assumed to be partly unknown and of the same type, e.g. offset terminations. Their reflection coefficients are modeled over frequency and identified during the calibration along with the VNA error terms. This novel...
We study for the first time errors in on-wafer scattering parameter measurements caused by the parasitic microstrip-like mode propagation in conductor-backed coplanar waveguide (CB-CPW). We determine upper bound for these errors for typical CPW devices such as a matched load, an open circuit, and a transmission line section. To this end, we develop an electromagnetic-simulations-based multimode three-port...
We present a new four-state interferometer for measuring vectorial reflection coefficient from 50 to 1800 MHz. The interferometer is composed of a four-state phase shifter, a double-directional coupler and a spectrum analyzer with an in-built tracking generator. We describe a design of the interferometer and methods developed for its calibration and de-embedding the measurements. Experimental data...
The paper presents a rigorous analysis of systematic errors in the four-noise parameter determination of a two-port network using the cold-source technique. The method is based on an original model that accounts for imperfectly-measured source reflection coefficients due to residual errors within a vector network analyzer (VNA). The authors show that even small VNA errors may seriously deteriorate...
Jednym z elementów badań odbiorczych lub okresowych w instalacjach elektroenergetycznych o napięciu niższym niż 1kV jest ocena skuteczności samoczynnego wyłączenia. W budownictwie powszechnie jest stosowany układ sieci TN. Ocenę skuteczności samoczynnego wyłączenia w badanej instalacji lub odbiorniku przeprowadza się przez porównanie wartości impedancji zmiennej pętli obwodu zwarciowego, wartości...
We present a systematic nonlinear procedure for designing microwave oscillators utilising a nonlinear PHEMT model, the negative resistance approach and the describing function concept. The procedure is applied in the design of a 24 GHz oscillator, which is then realised in hybrid technology. Measurement results show - 6% shift in the frequency but an acceptable agreement in the output power. A detailed...
Novel multi-state impedance tuner for use in on-wafer noise-parameter measurement system is reported. It is based on just three commercial GaAs MMIC switches that connect into or out the circuit six delay sections composed of natural and artificial transmission lines, and thus provide 36 distinct impedances at each frequency. The tuner's broadband operation (50 - 2000 MHz) was provided by optimisation...
The assessment of uncertainties of a two-port noise parameters measurement, presented in the paper, relies on modeling of sources of errors and an investigation of propagation of the errors through a measurement system. This approach is based on a simplified additive error model and small-change sensitivity analysis. The evaluated uncertainties agrees with those observed in experiments. This method...
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