ORCID Profile
0000-0002-0718-1727
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Communications Technologies | Microwave And Millimetrewave Technology | Physical Sciences Not Elsewhere Classified | Electrical and Electronic Engineering | Instruments And Techniques | Lasers and Quantum Electronics | Microwave and Millimetrewave Theory and Technology | Astronomical and Space Instrumentation | Ionospheric And Magnetospheric Physics | Electrical Engineering | Condensed Matter Physics—Electronic And Magnetic Properties; | Satellite Communications | Photonics and Electro-Optical Engineering (excl. Communications) | Satellite Communications | Optical Physics | Biomaterials | Geodesy | Optical And Photonic Systems | Quantum Physics not elsewhere classified | Signal Processing | Other Physical Sciences | Dynamics, Vibration and Vibration Control | Astronomy And Astrophysics | Antennas and Propagation | Photonics, Optoelectronics and Optical Communications | Atomic And Molecular Physics | Optical Fibre Communications | Physical Sciences not elsewhere classified | Atomic and Molecular Physics | Quantum Optics And Lasers
ANZSRC Socio-Economic Objective (SEO)
Physical sciences | Expanding Knowledge in the Physical Sciences | Scientific instrumentation | Expanding Knowledge in Technology | Expanding Knowledge in Engineering | Industrial instrumentation | Communication equipment | Telecommunications | Air Force | Measurement standards and calibration services not elsewhere classified | Communication Networks and Services not elsewhere classified | Emerging Defence Technologies | Integrated circuits and devices |
Related Links
Publications
Temperature Dependence of Permittivity and Loss Tangent of Lithium Tantalate at Microwave Frequencies
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2004
High-Q sapphire-rutile frequency-temperature compensated microwave dielectric resonators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-1998
DOI: 10.1109/58.677747
Abstract: A sapphiro-rutile composite resonator was constructed from a cylindrical sapphire monocrystal with two thin disks of monocrystal rutile held tightly against the ends. Because rutile exhibits low loss and an opposite temperature coefficient of permittivity to sapphire, it is an ideal material for compensating the frequency-temperature dependence of a sapphire resonator. Most of the electromagnetic modes in the composite structure exhibited turning points (or compensation points) in the frequency-temperature characteristic. The temperatures of compensation for the WG quasi TM modes were measured to be below 90 K with Q-factors of the order of a few million depending on the mode. For WG quasi TE modes, the temperatures of compensation were measured to be between 100 to 160 K with Q-factors of the order of a few hundreds of thousands, depending on the mode. The second derivatives of the compensation points were measured to be of the order 0.1 ppm/K(2 ), which agreed well with the predicted values.
Microwave cavity search for paraphotons
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3460192
Spherical Bragg reflector resonators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2004
DOI: 10.1109/TUFFC.2004.1334838
Abstract: In this paper we introduce the concept of the spherical Bragg reflector (SBR) resonator. The resonator is made from multiple layers of spherical dielectric, loaded within a spherical cavity. The resonator is designed to concentrate the energy within the central region of the resonator and away from the cavity walls to minimize conductor losses. A set of simultaneous equations is derived, which allows the accurate calculation of the dimensions of the layers as well as the frequency. The solution is confirmed using finite-element analysis. A Teflon-free space resonator was constructed to prove the concept. The Teflon SBR was designed at 13.86 GHz and exhibited a Q-factor of 22,000, which agreed well with the design values. This represents a factor of 3.5 enhancement over a resonator limited by the loss-tangent of Teflon. Similarly, SBR resonators constructed with low-loss materials could achieve Q-factors of the order of 300,000.
High-Q frequency-temperature compensated sapphire/rutile resonator
Publisher: Institution of Engineering and Technology (IET)
Date: 2000
DOI: 10.1049/EL:20000575
New method to build a high stability sapphire oscillator from the temperature compensation of the difference frequency between modes of orthogonal polarization
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2003
DOI: 10.1109/TUFFC.2003.1193614
Abstract: A new method to construct a high stability sapphire oscillator is presented (patent pending). The method relies on the anisotropic fractional temperature coefficients of frequency (TCF) of orthogonally polarized modes. We show that it is possible to design a resonator with transverse electric and magnetic modes at different frequencies, but with the same TCF in units hertz per kelvin, resulting in temperature compensation of the difference frequency. Compensation was demonstrated between 50 to 77 K by measuring the difference frequency of two microwave oscillators frequency locked to orthogonally polarized whispering gallery modes. Curvature of the compensation points was measured to be 1 to 3 x 10(-8) K(-2) between 50 and 77 K. This technique enables the construction of temperature compensated oscillators at any temperature and does not require dielectric, paramagnetic, or mechanical compensation techniques. Considering the above parameters, we show that it is possible to construct oscillators with fractional frequency instability at tau = 1s, of order 7.6 x 10(-15) at solid nitrogen temperature (approximately 50 K).
High precision microwave interferometers and oscillators for applied and fundamental physics applications
Publisher: IEEE
Date: 09-2010
Cryogenic properties of a diamond sample at microwave frequencies
Publisher: IEEE
Date: 09-2010
High-Resolution Flicker-Noise-Free Frequency Measurements of Weak Microwave Signals
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2011
Reference Signal Synthesized from a Cryogenic Sapphire Oscillator Improved by Power Control Servo
Publisher: IOP Publishing
Date: 07-04-2006
DOI: 10.1143/JJAP.45.2827
Simplified Three-Cornered-Hat Technique for Frequency Stability Measurements
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2014
The microwave characterization of single crystal lithium and calcium fluoride at cryogenic temperatures
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2004
DOI: 10.1109/TUFFC.2004.1295423
Abstract: The whispering-gallery mode method is used for very accurate permittivity and dielectric loss measurements of single crystal lithium fluoride (LiF) and calcium fluoride (CaF2) over the temperature range of 4.5 K to 300 K. The absolute uncertainty in the real part of permittivity was estimated to be less than 0.1%, and it was limited principally by uncertainty in dimensions of the s les. Dielectric losses were measured with uncertainties of about 10% limited by the accuracy of Q-factor measurements. The measured materials exhibited dielectric losses between 2-4 x 10(-7) near 5 K. The relative permittivity was evaluated as 6.502 (4.9 K) to 6.844 (296 K) at 17.5 GHz for CaF2 and 8.534 (4.6 K) to 9.063 (300 K) at 13.5 GHz for LiF.
Designs of a microwave TE/sub 011/ mode cavity for a space borne H-maser
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2005
DOI: 10.1109/TUFFC.2005.1561619
Abstract: Method of Lines and Finite Element Analysis investigations have been performed to optimize parameters in a TE011 mode cavity resonator suitable for a spaceborne hydrogen maser. We report on designs that were explored to find a global maximum in the important design parameters for the microwave cavity used in a hydrogen maser. The criteria sought in this exercise were both the minimization of the total volume of the cavity and the maximization of the product of the z-component of the magnetic energy filling factor and the cavity TE011 mode Q-factor (Q.eta). Different configurations were studied. They were a sapphire tube in a copper cylinder, a sapphire tube in a copper cylinder with Bragg reflectors, and spherical copper cavities both empty and sapphire-lined on the inside cavity surface. At 320 K, the simulations resulted in an optimum product Q.eta = 4.9 x 10(4), with an inner cavity radius of 80 mm and unity aspect ratio. This represents a 54% improvement over an earlier design. The expected increase in the product Q . eta) with the inclusion of Bragg reflectors to the sapphire tube was not achieved. Moreover, the z-component of the magnetic energy filling factor was greatly reduced due to an increase in the radial magnetic field. The sapphire-lined spherical cavity showed no better performance than an equivalent-sized empty copper spherical cavity. For the empty cavity the simulations resulted in the product Q.eta = 4.4 x 10(4). The empty spherical cavity resonator is not suitable for the spaceborne hydrogen maser as the total volume in this case is 33% larger than that of the optimized sapphire tube resonator.
Frequency-temperature sensitivity reduction with optimized microwave Bragg resonators
Publisher: AIP Publishing
Date: 05-01-2017
DOI: 10.1063/1.4973676
Abstract: Dielectric resonators are employed to build state-of-the-art low-noise and high-stability oscillators operating at room and cryogenic temperatures. A resonator temperature coefficient of frequency is one criterion of performance. This paper reports on predictions and measurements of this temperature coefficient of frequency for three types of cylindrically symmetric Bragg resonators operated at microwave frequencies. At room temperature, microwave Bragg resonators have the best potential to reach extremely high Q-factors. Research has been conducted over the last decade on modeling, optimizing, and realizing such high Q-factor devices for applications such as filtering, sensing, and frequency metrology. We present an optimized design, which has a temperature sensitivity 2 to 4 times less than current whispering gallery mode resonators without using temperature compensating techniques and about 30% less than other existing Bragg resonators. Also, the performance of a new generation single-layered Bragg resonator, based on a hybrid-Bragg-mode, is reported with a sensitivity of about −12 ppm/K at 295 K. For a single reflector resonator, it achieves a similar level of performance as a double-Bragg-reflector resonator but with a more compact structure and performs six times better than whispering-gallery-mode resonators. The hybrid resonator promises to deliver a new generation of high-sensitivity sensors and high-stability room-temperature oscillators.
Simple design rules for optimal design of dielectric temperature-compensated sapphire resonators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2003
DOI: 10.1109/TUFFC.2003.1235331
Abstract: It has been shown that the use of two dielectric crystals with opposite temperature coefficient of permittivity allows the realization of a resonator with a zero temperature coefficient of frequency. By using sapphire and rutile materials, which have low-loss tangents, some compensated resonators with very high Q-factors have been realized. In this work we develop rules that greatly simplify the design of a dielectric-compensated resonator. We show that the optimum design for compensation at a specific temperature may be determined by simply selecting the aspect ratio of the sapphire resonator.
Microwave cavity hidden sector photon threshold crossing
Publisher: American Physical Society (APS)
Date: 27-09-2011
Improving the frequency stability of microwave oscillators by utilizing the dual-mode sapphire-loaded cavity resonator
Publisher: IOP Publishing
Date: 10-07-2002
Cryogenic sapphire oscillator with exceptionally high long-term frequency stability
Publisher: IEEE
Date: 05-2007
Use of Whispering-Gallery Modes and Quasi-${\rm TE}_{0{ np}}$ Modes for Broadband Characterization of Bulk Gallium Arsenide and Gallium Phosphide Samples
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2008
Whispering-gallery mode technique applied to the measurement of the dielectric properties of Langasite between 4 K and 300 K
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2004
Microwave characterisation of BaCe2Ti5O15 and Ba5Nb4O15 ceramic dielectric resonators using whispering gallery mode method
Publisher: Elsevier BV
Date: 09-2000
Microwave secondary frequency standards: stability limits due to intrinsic fluctuations in frequency discriminator
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2000
DOI: 10.1109/75.862230
Generation of 103.75 GHz CW Source With $5.10^{-16}$ Frequency Instability Using Cryogenic Sapphire Oscillators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2012
Room temperature measurement of the anisotropic loss tangent of sapphire using the whispering gallery mode technique
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2006
DOI: 10.1109/TUFFC.2006.1588389
Abstract: The anisotropic loss tangent has been determined in monocrystalline sapphire for components parallel and perpendicular to the crystal axis, using the whispering gallery (WG) mode method. The Q-factors of quasi-TE and quasi-TM modes were measured precisely in four cylindrical sapphire resonators at room temperature, from which was determined a maximum attainable Q-factor of (2.1 +/- 0.2) x 10(5) at 9 GHz in a quasi-TM mode. Sapphire dielectric material from three different manufacturers was compared over the 270-345 K temperature range and the 5-16 GHz frequency range.
Temperature dependence of Ti3+ doped sapphire whispering gallery mode resonator
Publisher: Institution of Engineering and Technology (IET)
Date: 1998
DOI: 10.1049/EL:19980177
Invited Article: Design techniques and noise properties of ultrastable cryogenically cooled sapphire-dielectric resonator oscillators
Publisher: AIP Publishing
Date: 05-2008
DOI: 10.1063/1.2919944
Abstract: We review the techniques used in the design and construction of cryogenic sapphire oscillators at the University of Western Australia over the 18year history of the project. We describe the project from its beginnings when sapphire oscillators were first developed as low-noise transducers for gravitational wave detection. Specifically, we describe the techniques that were applied to the construction of an interrogation oscillator for the PHARAO Cs atomic clock in CNES, in Toulouse France, and to the 2006 construction of four high performance oscillators for use at NMIJ and NICT, in Japan, as well as a permanent secondary frequency standard for the laboratory at UWA. Fractional-frequency fluctuations below 6×10−16 at integration times between 10 and 200s have been repeatedly achieved.
Dielectric characterisation of Barium Fluoride at cryogenic temperatures using TE011 and quasi TE0mn mode dielectric resonators
Publisher: Elsevier BV
Date: 10-2006
New methods of testing Lorentz violation in electrodynamics
Publisher: American Physical Society (APS)
Date: 07-01-2005
Exciting traveling waves in high Q structures using microstrip
Publisher: Elsevier BV
Date: 2007
Second generation 50 K dual-mode sapphire oscillator
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2006
DOI: 10.1109/TUFFC.2006.1593366
Abstract: Low-temperature, high-precision sapphire resonators exhibit a turning point in mode frequency-temperature dependence at around 10 K. This, along with sapphire's extremely low dielectric losses at microwave frequencies, results in oscillator fractional frequency stabilities on the order of 10(-15). At higher temperatures the lack of a turning point makes single-mode oscillators very sensitive to temperature fluctuations. By exciting two quasi-orthogonal whispering gallery (WG) modes in a single sapphire resonator, a turning point in the frequency-temperature dependence can be found in the beat frequency between the two modes. A temperature control technique based on mode frequency temperature dependence has been used to maintain the sapphire at this turning point and the fractional frequency instability of the beat frequency has been measured to be at a level of 4.3 X 10(-14) over 1 s, dropping to 3.5 X 10(-14) over 4 s integration time.
Radio frequency signals synthesised from independent cryogenic sapphire oscillators
Publisher: Institution of Engineering and Technology (IET)
Date: 02-2014
DOI: 10.1049/EL.2013.3481
High-power solid-state sapphire whispering gallery mode maser
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2010
Microwave properties of semi-insulating silicon carbide between 10 and 40 GHz and at cryogenic temperatures
Publisher: AIP Publishing
Date: 15-03-2011
DOI: 10.1063/1.3561431
Cryogenic resonant microwave cavity searches for hidden sector photons
Publisher: American Physical Society (APS)
Date: 03-12-2013
Extending the Frequency Range of Digital Noise Measurements to the Microwave Domain
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2014
Precision Microwave Oscillators and Interferometers to Test Lorentz Invariance in Electrodynamics (an Update)
Publisher: IEEE
Date: 05-2007
THE IMPACT OF FREQUENCY STANDARDS ON COHERENCE IN VLBI AT THE HIGHEST FREQUENCIES
Publisher: American Astronomical Society
Date: 14-09-2012
Proposal for a new Michelson–Morley experiment using a single whispering spherical mode resonator
Publisher: Elsevier BV
Date: 07-2002
Synthesis chains based on ultra-stable cryogenic sapphire oscillator at NICT
Publisher: IEEE
Date: 04-2009
Rotating odd-parity Lorentz invariance test in electrodynamics
Publisher: American Physical Society (APS)
Date: 22-12-2009
Cryogenic sapphire oscillator using a low- vibration design pulse-tube cryocooler: first results
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2010
Long term operation, performance and applications of cryogenic sapphire oscillators
Publisher: IEEE
Date: 2005
An optical beam frequency reference with 10−14 range frequency instability
Publisher: AIP Publishing
Date: 20-07-2009
DOI: 10.1063/1.3184578
High power solid-state sapphire Whispering Gallery mode maser
Publisher: IEEE
Date: 04-2009
<title>Recent advances in measurements of permitivity and dielectric losses at microwave frequencies</title>
Publisher: SPIE
Date: 07-04-2004
DOI: 10.1117/12.560676
Electromagnetic properties of polycrystalline diamond from 35 K to room temperature and microwave to terahertz frequencies
Publisher: AIP Publishing
Date: 05-2011
DOI: 10.1063/1.3580903
Abstract: Dielectric resonators are key components for many microwave and millimeter wave applications, including high-Q filters and frequency-determining elements for precision frequency synthesis. These often depend on the quality of the dielectric material. The commonly used material for building the best cryogenic microwave oscillators is sapphire. However, sapphire is becoming a limiting factor for higher frequency designs. It is, then, important to find new candidates that can fulfill the requirements for millimeter wave low noise oscillators at room and cryogenic temperatures. These clocks are used as a reference in many fields, such as modern telecommunication systems, radio astronomy (very-long-baseline interferometry), and precision measurements at the quantum limit. High resolution measurements were taken of the temperature-dependence of the electromagnetic properties of a polycrystalline diamond disk at temperatures between 35 and 330 K at microwave to submillimeter wave frequencies. The cryogenic measurements were made using a TE01δ dielectric mode resonator placed inside a vacuum chamber connected to a single-stage pulse-tube cryocooler. The high frequency characterization was performed at room temperature using a combination of a quasi-optical two-lens transmission setup, a Fabry–Perot cavity, and a whispering gallery mode resonator excited with waveguides. Our CVD diamond s le exhibits a decreasing loss tangent with increasing frequencies. We compare the results with well known crystals. This comparison makes it clear that polycrystalline diamond could be an important material for generating stable frequencies at millimeter waves.
Observation of persistent photoconductivity and modified permittivity in bulk gallium arsenide and gallium phosphide samples at cryogenic temperatures
Publisher: IEEE
Date: 04-2009
Invited Article: Dielectric material characterization techniques and designs of high-Q resonators for applications from micro to millimeter-waves frequencies applicable at room and cryogenic temperatu
Publisher: AIP Publishing
Date: 03-2014
DOI: 10.1063/1.4867461
Abstract: Dielectric resonators are key elements in many applications in micro to millimeter wave circuits, including ultra-narrow band filters and frequency-determining components for precision frequency synthesis. Distributed-layered and bulk low-loss crystalline and polycrystalline dielectric structures have become very important for building these devices. Proper design requires careful electromagnetic characterization of low-loss material properties. This includes exact simulation with precision numerical software and precise measurements of resonant modes. For ex le, we have developed the Whispering Gallery mode technique for microwave applications, which has now become the standard for characterizing low-loss structures. This paper will give some of the most common characterization techniques used in the micro to millimeter wave regime at room and cryogenic temperatures for designing high-Q dielectric loaded cavities.
Modified permittivity observed in bulk gallium arsenide and gallium phosphide samples at 50K using the whispering gallery mode method
Publisher: AIP Publishing
Date: 11-08-2008
DOI: 10.1063/1.2969905
Abstract: Whispering gallery modes in bulk cylindrical gallium arsenide and gallium phosphide s les have been examined both in darkness and under white light at 50K. In both s les we observed change in permittivity under light and dark conditions. This results from a change in the polarization state of the semiconductor, which is consistent with a free electron-hole creation/recombination process. The permittivity of the semiconductor is modified by free photocarriers in the surface layers of the s le which is the region s led by whispering gallery modes.
High Q-factor Bragg-reflection sapphire-loaded cavity TE/sub 01/spl delta// mode resonators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2002
DOI: 10.1109/TUFFC.2002.1159842
Abstract: An innovative method of enhancing the quality factor of TE01delta cavity resonators with a dielectric tube made of monolithic sapphire is presented. Very high Q-factor is achieved by employing a Bragg reflection technique. A TE01delta mode in a copper cavity was measured to have a Q-factor of 1 x 10(5) at 8.78 GHz and 290 K. This is only 30% less than the limit due to the loss tangent of the dielectric material. The technique confines electromagnetic energy in the sapphire dielectric and in the vacuum well away from the cavity walls, thus reducing the surface losses in the copper shield. The technique offers some significant advantages over other methods. One advantage is the very low spurious mode density, which can improve filter and resonator design capabilities. Another is the small compact design, with a single sapphire piece, as compared to previously published Bragg reflection techniques. Finite element simulations and experimental data for this method were compared and found to be in very good agreement. The cavity dimensions were optimized to achieve maximum quality factor.
Bidirectional microwave and optical signal dissemination
Publisher: The Optical Society
Date: 29-02-2016
DOI: 10.1364/OL.41.001014
Operating Atomic Fountain Clock Using Robust DBR Laser: Short-Term Stability Analysis
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2017
Low Phase Noise Frequency Synthesis for Ultrastable $X$ -Band Oscillators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2017
Room temperature dual-mode oscillator - first results
Publisher: IEEE
Date: 2005
Resonant regeneration in the sub-quantum regime – A demonstration of fractional quantum interference
Publisher: Elsevier BV
Date: 04-2011
‘Fast light’ effect in experiments with cryogenic resonators
Publisher: IOP Publishing
Date: 30-10-2012
High-Q factor frequency-temperature compensated sapphire Bragg distributed resonator
Publisher: Institution of Engineering and Technology (IET)
Date: 2003
DOI: 10.1049/EL:20030234
The dependence of the permittivity of sapphire on thermal deformation at cryogenic temperatures
Publisher: IOP Publishing
Date: 11-11-2003
Using Precision Oscillators and Interferometers to Test Fundamental Physics
Publisher: IEEE
Date: 06-2006
Analysis of the rutile-ring method of frequency-temperature compensating a high-Q whispering gallery sapphire resonator
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2001
DOI: 10.1109/58.920715
Abstract: The rutile-ring method of dielectrically frequency-temperature compensating a high-Q whispering gallery (WG) sapphire resonator is presented. Two and three-dimensional finite element (FE) analysis has been implemented to design and analyze the performance of such resonators, with excellent agreement between theory and experiment. A high-Q factor of 30 million at 13 GHz and compensation temperature of 56 K was obtained. It is shown the frequency-temperature compensation can occur either because the rutile adds a small perturbation to the sapphire resonator or because of a mode interaction with a resonant mode in the rutile. The characteristics of both of these methods are described, and it is shown that for high frequency stability, it is best to compensate perturbatively.
Complex paramagnetic susceptibility in titanium-doped sapphire at microwave frequencies
Publisher: IOP Publishing
Date: 14-03-2001
Temperature fluctuations in a solid-nitrogen cooled secondary frequency standard
Publisher: Elsevier BV
Date: 2002
Complex permittivity of some ultralow loss dielectric crystals at cryogenic temperatures
Publisher: IOP Publishing
Date: 1999
Frequency transposing measurement technique for oscillator comparisons
Publisher: Institution of Engineering and Technology (IET)
Date: 07-2013
DOI: 10.1049/EL.2013.1604
Resonator power to frequency conversion in a cryogenic sapphire oscillator
Publisher: AIP Publishing
Date: 22-07-2013
DOI: 10.1063/1.4816284
Abstract: We report on the measurement and characterization of power to frequency conversion in the resonant mode of a cryogenic sapphire loaded cavity resonator, which is used as the frequency discriminating element of a loop oscillator circuit. Fluctuations of power incident on the resonator lead to changes in radiation pressure and temperature in the sapphire dielectric, both of which contribute to a shift in the resonance frequency. We measure a modulation and temperature independent radiation pressure induced power to frequency sensitivity of −0.15 Hz/mW and find that this is the primary factor limiting the stability of the resonator frequency.
Anisotropic paramagnetic susceptibility of crystalline ruby at cryogenic temperatures
Publisher: IEEE
Date: 05-2007
Proposal for a new test of the time independence of the fine structure constant α using orthogonally polarized whispering gallery modes in a single sapphire resonator
Publisher: American Physical Society (APS)
Date: 13-03-2003
Adapting a Cryogenic Sapphire Oscillator for Very Long Baseline Interferometry
Publisher: IOP Publishing
Date: 05-2011
DOI: 10.1086/660156
Whispering gallery method of measuring complex permittivity in highly anisotropic materials: discovery of a new type of mode in anisotropic dielectric resonators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2001
DOI: 10.1109/19.918182
Ultra-Stable Very-Low Phase-Noise Signal Source for Very Long Baseline Interferometry Using a Cryocooled Sapphire Oscillator
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2011
Optimum design of a high-Q room- temperature whispering-gallery-mode X-band sapphire resonator
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2013
Detrapping and retrapping of free carriers in nominally pure single crystal GaP, GaAs, and 4H–SiC semiconductors under light illumination at cryogenic temperatures
Publisher: AIP Publishing
Date: 15-11-2010
DOI: 10.1063/1.3514009
Abstract: We report on extremely sensitive measurements of changes in the microwave properties of high purity nonintentionally-doped single-crystal semiconductor s les of gallium phosphide, gallium arsenide, and 4H–silicon carbide when illuminated with light of different wavelengths at cryogenic temperatures. Whispering gallery modes were excited in the semiconductors while they were cooled on the coldfinger of a single-stage cryocooler and their frequencies and Q-factors measured under light and dark conditions. With these materials, the whispering gallery mode technique is able to resolve changes of a few parts per million in the permittivity and the microwave losses as compared with those measured in darkness. A phenomenological model is proposed to explain the observed changes, which result not from direct valence to conduction band transitions but from detrapping and retrapping of carriers from impurity/defect sites with ionization energies that lay in the semiconductor band gap. Detrapping and retrapping relaxation times have been evaluated from comparison with measured data.
Current limitations of cryogenic microwave oscillator frequency stability
Publisher: IEEE
Date: 05-2014
Observation of persistent photoconductivity in bulk gallium arsenide and gallium phosphide samples at cryogenic temperatures using the whispering gallery mode method
Publisher: AIP Publishing
Date: 12-2008
DOI: 10.1063/1.3033559
Abstract: Whispering gallery modes in bulk cylindrical gallium arsenide and gallium phosphide s les have been examined both in darkness and under white light at cryogenics temperatures ≤50 K. In both cases persistent photoconductivity was observed after initially exposing semiconductors to white light from a halogen l . Photoconductance decay time constants for GaP and GaAs were determined to be 0.900±0.081 and 1.098±0.063 ns, respectively, using this method.
Cryogenic dual-mode resonator for a fly-wheel oscillator for a caesium frequency standard
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2002
DOI: 10.1109/TUFFC.2002.1041076
Abstract: A dual-mode, sapphire-loaded cavity (SLC) resonator has been designed and optimized with the aid of finite element software. The resonance frequency was designed to be near the frequency of a Cs atomic frequency standard. Experimental tests are shown to agree very well with calculations. The difference frequency of two differently polarized modes is shown to be a highly sensitive temperature sensor in the 50 to 80 K temperature range. We show that an oscillator based on this resonator has the potential to operate with fractional frequency instability below 10(-14) for measurement times of 1 to 100 seconds. This is sufficient to operate an atomic clock at the quantum projection noise limit.
Design of high-Q frequency-temperature compensated dielectric resonators
Publisher: Institution of Engineering and Technology (IET)
Date: 1999
DOI: 10.1049/EL:19990205
Novel interferometric frequency discriminators for low noise microwave applications
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 05-2001
DOI: 10.1109/58.920704
Abstract: New configurations of interferometric frequency discriminators (FD) for frequency stabilization of microwave oscillators are examined. The new FDs are arranged in single directional (SD) (patented), bi-directional (BD) (patent pending), and dual reflection (DR) (patent pending) configurations. In the SD configuration, the signals reflected off and transmitted through the resonator separately pass through different arms of the interferometer. In the BD configuration, microwaves pass in both directions through each arm of the interferometer. In the DR configuration, microwaves are reflected from the resonator as well as the compensating arm. The FD sensitivity is compared with that for the conventional interferometric FD and found to be 6 dB greater in the BD configuration. Because no circulator is required within the interferometer in either the BD or the DR FD, the discriminator's phase noise floor is not limited by the circulator contribution.
Dependence of the dielectric permittivity of single-crystal quartz on thermal deformation at cryogenic temperatures
Publisher: AIP Publishing
Date: 10-2007
DOI: 10.1063/1.2785019
Abstract: The whispering gallery mode technique applied to single-crystal quartz has been used as a precise method to determine the dependence of the dielectric permittivity of pure single-crystal quartz on temperature-induced dimensional changes at cryogenic temperatures. The anisotropic temperature coefficients of permittivity (TCP) perpendicular and parallel to the crystal axis have been determined between 4.7 and 280 K. The difference between TCPs perpendicular and parallel to the crystal axis, near 17 GHz, between 160 and 300 K is approximately half the thermal expansion coefficient perpendicular to the crystal axis. Over this temperature range, the fractional change in the relative permittivity values perpendicular and parallel to the crystal axis, as a result of thermal expansion of the perpendicular dimension of the crystal, only differs by a small constant value.
Frequency-temperature compensation in Ti/sup 3+/ and Ti/sup 4+/ doped sapphire whispering gallery mode resonators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-1999
DOI: 10.1109/58.775666
Abstract: A new method of compensating the frequency-temperature dependence of high-and monolithic sapphire dielectric resonators near liquid nitrogen temperature is presented. This is achieved by doping monocrystalline sapphire with Ti(3+) ions. This technique offers significant advantages over other methods.
Properties of Gravitational Waves in Cosmological General Relativity
Publisher: Springer Science and Business Media LLC
Date: 23-05-2006
Stability measurements of frequency synthesis with cryogenic sapphire oscillators
Publisher: IEEE
Date: 04-2009
Ultra-high stability cryocooled sapphire microwave oscillators
Publisher: IEEE
Date: 05-2014
Frequency instability measurement system of cryogenic maser oscillator
Publisher: Institution of Engineering and Technology (IET)
Date: 2007
DOI: 10.1049/EL:20072684
Anisotropic paramagnetic susceptibility of crystalline ruby at cryogenic temperatures
Publisher: American Physical Society (APS)
Date: 12-01-2007
Extremely high-Q factor dielectric resonators for millimeter-wave applications
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2005
Publisher’s Note: Rotating odd-parity Lorentz invariance test in electrodynamics [Phys. Rev. D80, 125024 (2009)]
Publisher: American Physical Society (APS)
Date: 08-01-2010
Room temperature dual-mode oscillator—first results
Publisher: Institution of Engineering and Technology (IET)
Date: 2006
DOI: 10.1049/EL:20063490
Exciting traveling waves in high Q structures using microstrip
Publisher: IEEE
Date: 2005
Microwave Hidden Sector Photons at UWA.
Publisher: Deutsches Elektronen-Synchrotron, DESY, Hamburg
Date: 2011
High-Q whispering modes in empty spherical cavity resonators
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2003
DOI: 10.1109/TUFFC.2003.1251123
Abstract: This work presents the study of high-order modes in spherical cavity resonators. In general there are resonant mode families, degenerate in frequency, that "whisper" around the spherical surface. We call these whispering spherical (WS) mode sets. Each set includes the well-known whispering gallery (WG) mode, which propagates like a ray around the azimuth. Also, we identify a new mode, which we label the whispering longitudinal (WL) mode. This mode propagates as a wave front along the longitudinal direction. The rest of the degenerate set propagates like a combination of the WG and WL modes. We show that transverse electric WS modes have high geometric factors, greater than 2000, which increase linearly with frequency. This is an order of magnitude greater than that of a TM010 cylindrical resonator. Also, Q-factors as high as 65,000 at 13.3 GHz were measured at room temperature.
Whispering modes in anisotropic and isotropic dielectric spherical resonators
Publisher: Elsevier BV
Date: 11-2006
Drift-Compensated Low-Noise Frequency Synthesis Based on a cryoCSO for the KRISS-F1
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2016
Whispering Gallery mode microwave characterization of Ba(Mg1/3,Ta2/3)O3dielectric resonators
Publisher: IOP Publishing
Date: 28-10-1999
The dual-mode frequency-locked technique for the characterization of the temperature coefficient of permittivity of anisotropic materials
Publisher: IOP Publishing
Date: 14-10-2003
Cryogenic sapphire oscillator with exceptionally high long-term frequency stability
Publisher: AIP Publishing
Date: 13-11-2006
DOI: 10.1063/1.2387969
Abstract: The authors report on the development of a sapphire cryogenic microwave resonator oscillator with long-term fractional frequency stability of 2×10−17√τ for integration times τ& s and a negative drift of about 2.2×10−15∕day. The short-term frequency instability of the oscillator is highly reproducible and also state of the art: 5.6×10−16 for an integration time of τ≈20s.
Difference frequency technique to achieve frequency-temperature compensation in whispering-gallery sapphire resonator-oscillator
Publisher: Institution of Engineering and Technology (IET)
Date: 2002
DOI: 10.1049/EL:20020670
High-Q frequency–temperature compensated solid-nitrogen-cooled resonator-oscillators: first results
Publisher: Institution of Engineering and Technology (IET)
Date: 2004
DOI: 10.1049/EL:20040022
Generation of 100 GHz with parts in 1016 frequency stability using cryogenic sapphire oscillators
Publisher: IEEE
Date: 05-2011
High-Q frequency-temperature compensated solid-nitrogen-cooled resonator-oscillators: first results
Publisher: IEE
Date: 2004
DOI: 10.1049/CP:20040909
Continuous operation of an odd parity Lorentz Invariance test in electrodynamics using a microwave interferometer
Publisher: IEEE
Date: 05-2008
Influence of paramagnetic chromium ions in crystalline YAG at microwave frequencies
Publisher: IOP Publishing
Date: 18-06-2002
The Vector Algebra War: A Historical Perspective
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2016
Microwave cavity light shining through a wall optimization and experiment
Publisher: American Physical Society (APS)
Date: 24-09-2010
Distributed Bragg reflector resonators with cylindrical symmetry and extremely high Q-factors
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2005
DOI: 10.1109/TUFFC.2005.1397346
Abstract: A simple non-Maxwellian method is presented that allows the approximate solution of all the dimensions of a multilayered dielectric TE0qp mode cylindrical resonant cavity that constitutes a distributed Bragg reflection (DBR) resonator. The analysis considers an arbitrary number of alternating dielectric and free-space layers of cylindrical geometry enclosed by a metal cylinder. The layers may be arranged along the axial direction, the radial direction, or both. Given only the aspect ratio of the cavity, the desired frequency and the dielectric constants of the material layers, the relevant dimensions are determined from only a set of simultaneous equations, and iterative techniques are not required. The formulas were verified using rigorous method of lines (MoL) calculations and previously published experimental work. We show that the simple approximation gives dimensions close to the values of the optimum Bragg reflection condition determined by the rigorous analysis. The resulting solution is more compact with a higher Q-factor when compared to other reported cylindrical DBR structures. This is because it properly takes into account the effect of the aspect ratio on the Bragg antiresonance condition along the z-axis of the resonator. Previous analyses assumed the propagation in the z-direction was independent of the aspect ratio, and the layers of the Bragg reflector were a quarter of a wavelength thick along the z-direction. When the aspect ratio is properly taken into account, we show that the thickness of the Bragg reflectors are equivalent to the thickness of plane wave Bragg reflectors (or quarter wavelength plates). Thus it turns out that the sizes of the reflectors are related to the free-space propagation constant rather than the propagation constant in the z-direction.
Frequency stability of Ti3+-doped whispering gallery mode sapphire resonator oscillator at 34 K
Publisher: Institution of Engineering and Technology (IET)
Date: 2005
DOI: 10.1049/EL:20058179
Cryogenically cooled sapphire-rutile dielectric resonators for ultrahigh-frequency stable oscillators for terrestrial and space applications [atomic frequency standards]
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2000
DOI: 10.1109/22.853470
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