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Theses

Theses/Dissertations

2007

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Institution
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Articles 31 - 32 of 32

Full-Text Articles in Engineering

Thermo-Mechanical Design Of A 100 Ghz Mmic Power Amplifier Using Flip Chip Technology, Sean Cremin Jan 2007

Thermo-Mechanical Design Of A 100 Ghz Mmic Power Amplifier Using Flip Chip Technology, Sean Cremin

Theses

This thesis is concerned with the thermo-mechanical design, thermal modelling and temperature profile measurement of a 100 GHz flip chip bump bonded MMIC medium power amplifier.

Flip chip mounting offers superior RF performance in terms of output power, gain, noise figure and bandwidth. The thermal challenge was to dissipate approximately two watts of DC power from the GaAs MMIC (monolithic microwave integrated circuit) through Au (gold) stud bumps which equates to less then 7% of the total surface area of the die. Infrared thermographic images confirmed that the flip chip MMIC amplifier was functional with all eight FET stages on …


The Effect Of The Size Of Pinning Centres On The Critical Current Density In High-Temperature Superconductors, Salama Bakhit Sowaidan Al-Neaimi Jan 2007

The Effect Of The Size Of Pinning Centres On The Critical Current Density In High-Temperature Superconductors, Salama Bakhit Sowaidan Al-Neaimi

Theses

Superconductor materials that have no resistance to the flow of electricity are one of the last great frontiers of scientific discovery.

Superconductivity in these materials occurs particularly in the copper-oxide (CuO2) planes. However, since these materials are type-II superconductors, magnetic fields can penetrate these materials in quantized amounts of flux called vortices without completely destroying superconductivity, but producing some resistance, due to vortex motion. In order to overcome the resistance problem, vortices must be pinned to prevent their motion and hence eliminate the resistance.

In this work study we have performed extensive numerical simulations to study the effect …