Automated microwave device characterization set-up based on a technology-independent generalized Bias System

In this paper an automated laboratory set-up for the characterization of micro- and millimeter-wave electron devices under DC, small- and large-signal operation is described, which is based on a generalized, technology-independent bias system. The biasing parameters adopted, which are a linear combination between currents and voltages at the device ports, allow for a complete characterization of the desired empirical data (e.g. multi-frequency S-matrix) throughout all the regions in which the quiescent operation of the device can be conventionally divided, without any need for the switch between different biasing strategies. The look-up tables of experimental data obtained, which are carried out homogeneously with respect to the same couple of bias parameters, independently of the quiescent regions investigated, are particularly suitable for the characterization of empirical non-linear dynamic models for the electron device

On-wafer I/V measurement setup for the characterization of low-frequency dispersion in electron devices

Large-signal dynamic modelling of 111-V FETs cannot he simply based on DC i/v characteristics, when accurate performance prediction is needed. In fact, dispersive phenomena due to self-heating and/or traps (surface state densities and deep level traps) must be taken into account since they cause important deviations in the low-frequency dynamic drain current. Thus, static drain current characteristics should he replaced with a suitable model which also accounts for low-frequency dispersive effects. The research community has proposed different modelling approaches and quite often a characterisation by means of pulsed i/v measurement systems has been suggested as the more appropriate for the identification of lowfrequency drain current models. In the paper, a new largesignal measurement setup is presented which is based on simple low-frequency sinusoidal excitations and it is easily reproducible with conventional general-purpose lab instrumentation. Moreover, the proposed setup is adopted in the paper to extract a hackgating-like model for dispersive phenomen

Improvement of phemt intermodulation prediction through the accurate modelling of low-frequency dispersion effects

Large-signal dynamic modelling of III-V FETs cannot be simply based on de i/v characteristics, when accurate performance prediction is needed. In fact, dispersive phenomena due to self-heating and/or traps (surface state densities and deep level traps) must be taken into account since they cause important deviations in the dynamic drain current. In this paper, a recently proposed large-signal i/v measurement setup is exploited to extract an empirical model for lowfrequency dispersive phenomena in microwave electron devices. This i/v model is then embedded into a microwave large-signal PHEMT model. Eventually, a Ka-band highly linear power amplifier, designed by Ericsson using the Triquint GaAs 0.25pm PHEMT process, is used for model validation. Excellent intermodulation distortion predictions are obtained with different loads despite the extremely low power level of IMD products involved. This entitles the proposed model to be also used in the PA design process instead of conventional loadpull techniques whenever the high-linearity specifications play a major role

Accurate prediction of PHEMT intermodulation distortion using the nonlinear discrete convolution model

A general-purpose, technology-independent behavioral model is adopted for the intermodulation performance prediction of PHEMT devices. The model can be easily identified since its nonlinear functions are directly related to conventional DC and small-signal differential parameter measurements. Experimental results which confirm the model accuracy at high operating frequencies are provided in the pape

A broadband current sensor based on the X-Hall architecture

A broadband current sensor, which is fully integrated and galvanically-isolated, is presented in this paper. The current sensor relies only on a Hall-effect probe to realize the magnetic sensing core so as to minimize the cost and the occupied space. Bandwidth limitations of state-of-the-art Hall-effect probes are overcame by combining the novel X-Hall architecture with a wide bandwidth differential-difference current-feedback amplifier. A prototype implemented in 0.16 \u3bcm BCD technology demonstrates a bandwidth wider than 20 MHz. Offset, sensitivity and power consumption are comparable to the state of the art. This is the first Hall-only current sensor achieving a bandwidth higher than 3 MHz

Investigation of Phase Noise Generation in Microwave Electron Devices Operating in Nonlinear Regime Exploiting a Flexible Load\u2013 and Source\u2013Pull Oscillating Setup

In this paper, we present a flexible measurement setup for the characterization of the phase noise (PN) and frequency stability of microwave electron devices operating under nonlinear oscillating conditions. The setup embeds the device-under-test (DUT) within a feedback loop, and forces it into a large signal (LS) oscillating regime, by controlling the loop amplitude and phase. The DUT input and output terminations are also controlled, by exploiting load- and source-pull capabilities. By exploiting this setup, we demonstrate that the PN performance of microwave oscillators can be strongly affected by the device nonlinear RF working regime. As well known, the oscillator PN is mainly related to the frequency stability of the circuit and the active device low-frequency noise up-conversion to RF mechanisms. By using measurements performed with the proposed setup, it is shown that these aspects depend also on the device LS operating conditions; hence, the dynamic LS load line and the amplifying class of operation have a significant role for the oscillator PN. The experimental results described in the paper, along with the analyses proposed by using simulations, are in accordance with recently published nonlinear noise modeling approaches based on cyclostationary noise sources. The investigation performed by means of the setup can provide information for both the design of low-phase-noise (LPN) oscillators and the parameter extraction and validation of nonlinear noise models of electron devices. Furthermore, this setup is also proposed as a tool for the evaluation of power amplifier PN when a dedicated residual phase noise measurement system is not available