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Millimetre-wave Integrated Diode and Amplifier Sources

Final Report Summary - MIDAS (Millimetre-wave Integrated Diode and Amplifier Sources)

Executive Summary:
The terahertz (THz) spectral region between microwaves and infrared is of crucial importance to current and future space science, Earth observation and astronomy missions. In Earth observation, passive remote sensing of the atmosphere from space at millimetre and sub-millimetre wavelengths will play a key role in the MetOp Second Generation instruments. Terahertz radio measurements will be directed towards processes linking atmospheric composition and climate, notably including the essential climate variables water vapour and ozone. Recently two important astronomy programmes, the ALMA array and Herschel HIFI, have made important astronomical observations in this frequency band.
Despite these, and other potential applications that span the physical, biological, and medical sciences, the terahertz spectrum has yet to be fully exploited. In part this is because it remains difficult to generate conveniently useful amounts of power at THz frequencies. It was to address this problem, by developing generic integrated Schottky diode and amplifier sources using European technology, that the MIDAS project targeted.
The objective of the MIDAS project was to develop solid-state frequency sources based on European technology. To do this, within MIDAS a six fold frequency multiplier was developed to take the output from widely available synthesized sources and generate power covering the W-band, 75-110 GHz. This power was then amplified by power combining European MMIC amplifiers. The output from these amplifiers was further frequency multiplied in newly developed frequency doublers and triplers to generate power spanning the frequency range from 150 to 330 GHz. These final stage frequency multipliers were fabricated on 12 µm thick gallium arsenide membranes that included Schottky diodes with impedance matching networks and integrated capacitor structures. This was the first time that such structures had been fabricated in Europe. The circuit designs for these final stage multipliers also involved new power combining topologies in order to handle the high levels of power newly available to drive these sources.
In order to design these complicated non-linear structures, a new electro-thermal model was developed and implemented with new design and modelling techniques. In this process, the full electromagnetic model of the frequency multiplier was coupled with the thermal simulation of the structure and the physical modelling of the Schottky region.

Project Context and Objectives:
Full description is included in the attached report.

Project Results:
Full description is included in the attached report.

Potential Impact:
Full description is included in the attached report.

List of Websites:

http://www.stfc.ac.uk/RALSpace/Areas+of+expertise/Technology/Millimetre+and+terahertz+instrumentation/Projects/26678.aspx
Dr Byron Alderman
Byron.Alderman@stfc.ac.uk