F. van Raay

Error-corrected large-signal waveform measurement system combining network analyzer and sampling oscilloscope capabilities

A large-signal automatic stepped CW waveform measurement system for nonlinear device characterization is presented that combines the high accuracy of a vector network analyzer with the waveform measurement capabilities of a sampling oscilloscope. A large-signal error model and a corresponding coaxial calibration procedure are proposed to describe the systematic errors of the measurement setup. The error parameters and the correction algorithm are independent of the properties of the RF generator. System accuracy is investigated by Schottky diode verification measurements with different offsets from the reference plane. GaAs MESFET reflection and transmission response measurements with error correction extended to the planar device under test (DUT) reference planes are given. >

A new on-wafer large-signal waveform measurement system with 40 GHz harmonic bandwidth

A novel on-wafer large-signal waveform measurement system with a 40-GHz harmonic frequency range using a microwave transition analyzer is presented. Potential applications are illustrated by the measurement of the harmonic amplitude and phase spectra of the reflection and transmission response of a 0.3- mu m InGaAs pseudomorphic HEMT (high-electron-mobility transistor) under X-band sinusoidal stimulus.<<ETX>>

A Systematic State–Space Approach to Large-Signal Transistor Modeling

A state-space approach to large-signal (LS) modeling of high-speed transistors is presented and used as a general framework for various model descriptions of the dispersive features frequently observed for HEMTs at low frequency. Ensuring unrestricted LS-small-signal (SS) model compatibility, the approach allows to construct LS models from multibias SS S-parameter measurements. A general transformation between state-space models is derived, which are equivalent in the SS limit, but nonequivalent under LS stimuli. This transformation has the potential to compensate deviations observed by comparing model predictions with LS measurements and to find an optimum state linear LS model without any change of the SS behavior

Design and stability test of a 2-40 GHz frequency doubler with active balun

An ultra-broadband PHEMT MMIC frequency doubler is designed. It comprises a FET active balun stage and a push-pull doubler in common-source configuration. Due to the purely lumped-element concept, the required chip area is very low. Using broadband compensation and matching networks, a nearly flat output power performance up to a limit of 2/3 f/sub T/ with acceptable conversion loss is predicted in circuit simulations and confirmed with broadband waveform measurements. The stability of the entire circuit is investigated including hidden instabilities and arbitrary passive input and output load conditions based on a direct stability circle calculation.

Direct nonlinear FET parameter extraction using large-signal waveform measurements

A method that permits a direct nonlinear extraction of two FET parameters, the drain current generator, and the gate source capacitor from large-signal waveform measurements, is presented. For demonstration, the high-frequency characteristics of the nonlinear drain current generator for a GaAs MESFET and a MODFET are extracted. Significant differences between the DC and RF characteristics, are observed and interpreted.<<ETX>>

Precisely calibrated coaxial-to-microstrip transitions yield improved performance in GaAs FET characterization

An approach for calibrating coaxial-to-microstrip transitions up to 26.5 GHz with high precision is presented. An ideal through, noncritical open, noncritical short and surface absorber are used as microstrip standards for the calibration. The calibration measurement and an approach for extracting the scattering parameters of the transitions are described. Error-corrected results on broadband measurements of the scattering coefficients of packaged FETs in a hybrid circuit configuration are given. >

Direct nonlinear power MESFET parameter extraction and consistent modeling

A novel method is developed which permits a direct nonlinear FET parameter extraction of the gate source capacitor and diode, the drain current generator, and the avalanche breakdown characteristics from large-signal waveform measurements. Differences between the DC and RF characteristics of the drain current generator and the breakdown characteristics are observed and interpreted. The measured FET output power and phase spectra are compared with simulated results for different RF models of the nonlinear drain current generator. The proposed method is a valuable instrument for the analysis of the existing high-frequency FET nonlinearities and can be used to improve large-signal FET models.<<ETX>>

GaAs FET characterization in a quasi-monolithic Si environment

GaAs FET chips are planar embedded in a high resistivity silicon substrate and characterized up to 40 GHz in a coplanar environment. Hybrid interconnects (bonding wires) are replaced by thin film ones (air bridges). Small signal equivalent circuit extraction results confirm the expected low parasitic inductance values. These are reduced by more than 50% of the typical bonding wire interconnects.

A 40GHz large-signal double-reflectometer waveform measurement system designed for load-pull applications

A new large-signal measurement system combining waveform and load-pull characterization is presented. The setup comprises a double-reflectometer testset and a microwave transition analyzer (HP 71500A) as fundamental and harmonic receiver. The system calibration can be of TRL or modified SOLT type. For the first time, this setup permits a complete description of the harmonic amplitude and phase spectra under arbitrary loading conditions of the DUT. As an application example, an AlGaAs HEMT was. characterized for different reflective fundamental frequency output loads.

12 GHz coplanar quasi-monolithic oscillator

First results on coplanar quasi-monolithic (QM) circuits with GaAs FETs embedded in a silicon substrate are presented. Typical monolithic integration techniques are used for the fabrication of the passive circuitry and interconnects to the active devices. Measurements on a 12 GHz oscillator demonstrate the viability of the proposed technology.