Low Phase Noise Signal Generation utilising Oscillators, Resonators & Filters and Atomic Clocks Jeremy Everard
Jeremy Everard (M’90) obtained his BSc Eng. from the University of London, King’s College in 1976 and his PhD from the University of Cambridge in 1983. He worked in industry for six years at the GEC Marconi Research Laboratories, M/A-Com and Philips Research Laboratories on Radio and Microwave circuit design. At Philips he ran the Radio Transmitter Project Group.
He then taught RF and Microwave Circuit design, Opto-electronics and Electromagnetism at King’s College London for nine years while leading the Physical Electronics Research Group. He became University of London Reader in Electronics at King’s College London in 1990 and full Professor of Electronics at the University of York in September 1993. At York, he has also taught analogue IC design, filter design, Electromagnetism and RF & microwave circuit design.
In September 2007, he was awarded a five-year research chair in Low Phase Noise Signal Generation sponsored by BAE Systems and the Royal Academy of Engineering.
In the RF/Microwave area his research interests include: The theory and design of low noise oscillators using inductor capacitor (LC), Surface Acoustic Wave (SAW), crystal, dielectric, transmission line, helical and superconducting resonators; flicker noise measurement and reduction in amplifiers and oscillators; high efficiency broadband amplifiers; high Q printed filters with low radiation loss; broadband negative group delay circuits and MMIC implementations.
His research interests in Opto-electronics include: All optical self-routing switches which route data-modulated laser beams according to the destination address encoded within the data signal, ultra-fast 3-wave opto-electronic detectors and mixers for TeraHertz applications and distributed fibre optic temperature sensors.
Most recently, atomic clocks using coherent population trapping and ultra low phase noise microwave flywheel oscillator synthesiser chains with micro Hz resolution have been developed.
He has published papers on: oscillators, amplifiers, resonators and filters, all optical switching, optical components, optical fibre sensors and mm-wave optoelectronic devices and a book on ‘Fundamentals of RF Circuit Design with Low Noise Oscillators (Wiley) – New edition in progress -. He has filed Patent applications in many of these areas. He is a member of the IET, London and the IEEE (USA).
Oscillators are used in almost all consumer and professional electronic systems and the phase noise and jitter set the ultimate performance limit in navigation, communications and RADAR systems. It is therefore essential to develop simple accurate theories and design procedures to produce oscillators offering state of the art performance.
This talk will initially discuss the theory and design of a wide variety of oscillators offering the very best performance. Typically, this is achieved by splitting the oscillator design into its component parts and developing new amplifiers, resonators and phase shifters which offer high Q, high power handling and low thermal and transposed flicker noise.
Key features of oscillators offering the lowest phase noise available will be shown, for example: a 1.25GHz DRO produces -173dBc/Hz at 10kHz offset and a noise floor of -186dB and a 10 MHz crystal oscillator shows -123dBc/Hz at 1Hz and -149 at 10Hz.
New compact atomic clocks with ultra-low phase noise microwave synthesiser chains (with micro Hz resolution) will also be briefly described to demonstrate how the long-term stability can be improved.
New printed resonators (and thereby filters) demonstrate Qs exceeding 540 at 5GHz on PCBs and > 80 at 21GHz on GaAs MMICs. These resonators produce near zero radiation loss and therefore require no screening. L band 3D printed resonators demonstrate high Q (> 200) by selecting the standing wave pattern to ensure zero current through the via hole and new ultra-compact versions (4mm x 4mm) have been developed for use inside or underneath the package. Alumina based resonators demonstrating Qs >200,000 at X band have also been produced. Tunable versions (1%) have recently been developed.
As an academic, the aim is to produce the state of the art through insight and understanding, as well as to explain this to others. The author ran the first course on oscillators including a lab class at IMS 09. This was repeated in 2010, 2011. A battery powered lab kit offering 5 experiments with full theoretical and simulation support was provided. The kit also produced the state of the art performance with flicker noise corners around 200Hz. The methodology behind this course will be described. Theory and 5 experiments on the same day was part of the reason for success.
The next generation of oscillators will offer orders of magnitude improvement in performance. Our current attempts to do this will be described.