Tony Horseman

Clinical trials of a multistatic UWB radar for breast imaging

This paper presents the development of a 60-element Ultra-WideBand (UWB) radar system for breast cancer detection and its use in clinical trials. The new system operates in the frequency range of 4–8GHz and is an improvement of the teams previous designs both in terms of the number of measurements made (which is increased by a factor of approximately 4) and in terms of acquisition speed. The 60-antenna radar system has undergone an extensive Clinical Trial in the Breast Care Centre at Frenchay Hospital, Bristol. The rapid data acquisition has improved the accuracy of images while also providing a clinical experience that is more convenient and acceptable to patients.

Influence of winding design on losses in brushless AC IPM propulsion motors

This paper presents an analysis of loss in a brushless AC interior permanent magnet (IPM) propulsion motor with an emphasis on the high speed, field weakened region of the operating envelope. The loss distribution during short circuit operation is used as a simple measure for appraising field weakened performance. It is demonstrated the choice of winding configuration can have a significant impact on stator iron and rotor loss. The losses resulting from alternative fully pitched and short pitched windings are compared using three-dimensional finite element modelling. The theoretical loss predictions are experimentally validated on a prototype motor showing good agreement. A lumped-parameter thermal model of the motor is also developed and is used to confirm the estimated distribution between stator copper, stator iron, rotor iron and magnet losses.

A 60% PAE WCDMA Handset Transmitter Amplifier

This paper reports the design of a class-E envelope elimination and restoration (EER) based amplifier for a wideband code division multiple access handset application that attains 60% power-added efficiency at peak power output. Emphasis is placed on the envelope modulator that employs a novel split-frequency approach in order to attain an efficiency of 80% for this part of the system. In contrast to standard EER systems, the carrier is not amplitude limited, but rather predistorted to maintain both linearity and power efficiency. Performance in terms of efficiency, spectral output, and error vector magnitude is reported.