You are here:

• Macquarie Home »
• Faculty of Science »
• Department of Electronic Engineering

Publications in 2004

Saif Zaman and Anthony E Parker, [icece04] "Modelling surface state trapping in MOSFET devices," in 3rd International Conference on Electrical and Computer Engineering, (S Shahnawaz Ahmed, Ed.), Dhaka, Bangladesh, 28-30 Dec. 2004, pp. 799-802, The Institute of Electrical and Electronics Engineers, Inc., New York, NY, USA.

Abstract- empty abstract

Jonathan B Scott, Peter S Blockley, and Anthony E Parker, "A New Instrument Architecture for Millimetre-Wave Time-Domain Signal Analysis," in 63rd ARFTG Conference Digest, (J G Burns, Ed.), Fort Worth, Texas, USA, 11 June 2004, Automated RF Techniques Group, pp. 47-51, The Institute of Electrical and Electronics Engineers, Inc., New York, NY, USA

ISBN: 0-7803-8371-0,
CD-ROM File: //ARFTG/aper\_08.pdf.

Abstract- Current generation sampling oscilloscopes are limited by loss and discontinuity in transmission lines, connectors, and adapters, not the native bandwidth of the sampling gate. We propose a new architecture, method and algorithm that could enable the next generation of time-domain measurement instruments. The proposed instrument merges the network-analyzer concepts of calibration and correction with the conventional sampling oscilloscope

Anthony E Parker and James G Rathmell, "Contribution of self heating to intermodulation in FETs," in IEEE MTT-S International Microwave Symposium Digest of Technical Papers, (Karl Varian, Ed.), Fort Worth, Texas, USA, 6-11 June 2004, pp. 803-807, The Institute of Electrical and Electronics Engineers, Inc., New York, NY, USA

ISBN: 0-7803-8332-X.

Abstract- Self heating gives microwave FETs a temperature response to power dissipation. This is shown to be significant at high-frequency signal rates, even though the apparent time constant of heating is a few kilohertz. Self heating causes variation in intermodulation with frequency spacing and the extent of this variation is linked to bias. The frequency response of the heating process can be characterized from third-order intermodulation versus frequency spacing.

James Brinkhoff and Anthony E Parker, "Charge trapping and intermodulation in HEMTs," in IEEE MTT-S International Microwave Symposium Digest of Technical Papers, (Karl Varian, Ed.), Fort Worth, Texas, USA, 6-11 June 2004, pp. 799-802, The Institute of Electrical and Electronics Engineers, Inc., New York, NY, USA

ISBN: 0-7803-8332-X.

Abstract- Charge trapping effects in High Electron Mobility Transistors (HEMTs) are linked with anomalous intermodulation behavior, known as memory effects. This behavior can be clearly observed as changes in intermodulation levels with tone-spacing, and two-tone asymmetry. A Volterra-series analysis of an HEMT with trapping predicts the distortion accurately, and allows an understanding of the mechanisms involved.

Anthony E Parker and James G Rathmell, "Self-heating process in microwave transistors," in Workshop on Applications in Radio Science, (Phil Wilkinson, Ed.), Hobart, TAS, Australia, 18-20 Feb. 2004, Union Radio Science International, Commission C, pp. 1-8, National Committee for Radio Science

ISBN: 0-9580476-0-X,
CD-ROM File //proceedings/final/c/parker\_f.pdf.

Abstract- The temperature of microwave FETs is found to vary significantly at extremely high frequencies even though the fundamental thermal time constant is only a few kHz. This affects third-order intermodulation through a process involving temperature rise due to power dissipation at the fundamental and second harmonic frequencies of signal, which is mixed with the fundamental and second-order products of the device’s inherent nonlinearity. The process is strongly influenced by the spacing between the frequencies of signal components, which is exploited in a proposed method for characterizing the frequency dependence of self-heating. The impact on circuit performance is that distortion and intermodulation, which vary with bias and load conditions, additionally vary with self-heating. This additional dependence is overlooked in present circuit models and analysis techniques.

Peter S Blockley, Brenden Darcy, and Anthony E Parker, "An analytical method for analysing large-signal distortion," in Workshop on Applications in Radio Science, (Phil Wilkinson, Ed.), Hobart, TAS, Australia, 18-20 Feb. 2004, Union Radio Science International, Commission C, p. 1, National Committee for Radio Science

ISBN: 0-9580476-0-X,
CD-ROM File //proceedings/final/c/blockley\_i\_abs.pdf.

Abstract- Large-signal distortion is typically modelled with large-signal models or with describing functions. While these methods can provide an accurate prediction of system distortion, they do not provide analytic equations showing the effect on distortion as the signal traverses different regions of the load line. The Volterra series has been successfully used in weakly nonlinear systems to analytically investigate nonlinear distortion. The Volterra series is limited to mildly distorting systems due to the finite radius of convergence of the polynomials used to describe the nonlinearity. A method to extend the Volterra series technique for large-signal operation has been investigated. This enables better understanding of the individual contributions different regions of the load line make to the overall distortion characteristic.

Saif Zaman and Anthony E Parker, "Trap related current lag phenomena in heterojunction devices," in Workshop on Applications in Radio Science, (Phil Wilkinson, Ed.), Hobart, TAS, Australia, 18-20 Feb. 2004, Union Radio Science International, Commission C, p. 1, National Committee for Radio Science

ISBN: 0-9580476-0-X,
CD-ROM File //proceedings/final/c/zaman\_I\_abs.pdf.

Abstract- Current lag is a detrimental parasitic effect, which can seriously limit the performance of GaAs based device and integrated circuits. Gate lag affects digital circuits such as inverted chain, digital radio systems, the distortion characteristics of FET etc. Both gate lag and drain lag has been observed in Hetero Junction (HJ FET) devices. This lag is usually attributed to trap. We have carried out pulsed measurements to observe this current lag in HJFET devices. Gate lag is observed having more than one time constant. Although the cause of this current lag is thought to be due to surface state trap, further experiments are being carried out to verify this. The goal of this research is to develop an empirical model of surface state trapping in FET devices and hence to be able to predict the current lag.

James Brinkhoff and Anthony E Parker, "Device dispersion and intermodulation in HEMTs," in Workshop on Applications in Radio Science, (Phil Wilkinson, Ed.), Hobart, TAS, Australia, 18-20 Feb. 2004, Union Radio Science International, Commission B, pp. 1-8, National Committee for Radio Science

ISBN: 0-9580476-0-X,
CD-ROM File //proceedings/final/b/brinkhoff\_f.pdf.

Abstract- It has been shown previously that bias networks in microwave amplifiers can lead to complex intermodulation distortion effects. Here, we demonstrate that charge trapping effects in High Electron Mobility Transistors (HEMTs) can lead to additional anomalous intermodulation behaviour. This behaviour can be clearly observed as changes in intermodulation levels with tone-spacing, and two-tone asymmetry. Simulations using a simple model, that includes hole trapping effects, predicts similar intermodulation behaviour to measured behaviour. A Volterra-series analysis allows an understanding of the mechanisms involved.

This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author’s copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.

[Back to top]