Design of a uniplanar resonance phase-matched Josephson travelling-wave parametric amplifier
10th UK/Europe-China Workshop on Millimetre-Waves and Terahertz Technologies (UCMMT 2017) Institute of Electrical and Electronics Engineers (2017)
Abstract:
In this paper, we present the design of a resonance phase-matched Josephson travelling-wave parametric amplifier that have a 12GHz 3 dB-bandwidth centred near 10 GHz. Our design utilises a unilateral planar circuit structure which requires only a single layer of thin superconductor film deposited on a supporting substrate to reduce the fabrication complexity. The nonlinear medium of the device is provided by a series of Josephson junctions embedded in a coplanar waveguide with integrated shunt capacitor, and the dispersion of the transmission line is controlled by quarter wavelength resonators coupled capacitively to the feedline. Here, we describe in detail the electromagnetic designs of the various components of the amplifier, and the coupled-mode equations model that governs the three-wave mixing process. We extract the required circuit parameters of the amplifier through electromagnetic modelling, and determine the parametric gain-bandwidth product of the amplifier using an analytical model. Finally, we discuss the various design aspects that affect the overall performance of the amplifier.Preliminary design of an ALMA band 10 single-chip dual-polarisation SIS mixer
10th UK/Europe-China Workshop on Millimetre-Waves and Terahertz Technologies (UCMMT 2017) Institute of Electrical and Electronics Engineers (2017)
Abstract:
We present the design of an integrated dual-polarisation superconductor-insulator-superconductor (SIS) mixer operating at ALMA Band 10 frequency range. All the RF components, including the orthomode transducer (OMT), the quadrature hybrid and the SIS mixer circuits, are designed as superconducting planar circuits to form a single planar mixer chip. The mixer circuits will be fabricated using standard thin film deposition technology on an ultra-thin silicon-on-insulator (SoI) substrate. In this paper, we discuss in detail the design of the various RF components that make up the complete dual-polarisation SIS mixer chip, and provide the predicted performance using rigorous electromagnetic modelling. The optimised designs of these components are then integrated in a superconducting quantum mixer circuit modelling (SuperMix) environment for assessing the performance of the heterodyne parameters of the mixer such as mixer gain and noise temperature.A planar beam splitter for millimetre and sub-millimetre heterodyne mixer array
IEEE Transactions on Terahertz Science and Technology Institute of Electrical and Electronics Engineers (2017)
Abstract:
We present the design of a four-port planar circuit beam splitter comprising a microstrip and a coplanar waveguide (CPW) crossing each other. The CPW is fabricated in the ground plane (bottom layer) and the microstrip is deposited on top of the dielectric layer. A small section of the microstrip line is bent and aligned parallel to the central conductor of the bottom CPW, allowing the level of power coupling to be easily controlled by changing the length of the aligned section. The simple layout of the planar beam splitter makes it easy to fabricate in a wide frequency range from microwave to submillimetre (sub-mm) wavelengths. In this paper, we describe in details the electromagnetic design of the planar beam splitter and its predicted performances in the frequency range of 600– 700 GHz. We discuss the potential usage of the planar beam splitter as a replacement to the free-space beam splitter in receivers, in particular those using superconductor-insulatorsuperconductor (SIS) mixer arrays. To investigate the integrity of our design in a controlled way we scaled the design to operate in the Ku-band and measured the performance of several prototypes experimentally. Our tests showed good agreement between the measured performance and simulations.Spectral domain simulation of SIS frequency multiplication
28th International Symposium on Space Terahertz Technology (ISSTT 2017) National Radio Astronomy Observatory (2017)
Abstract:
In this paper, we compare simulations to experimental results for a new SIS frequency multiplier. To simulate these devices, we developed software based on spectral-domain analysis, which is ideal for simulating higherorder harmonics such as those present in a multiplier. In addition, we included the embedding circuit and interpolated the experimental I-V curve to allow the simulation to capture the experimental system as closely as possible. For the experimental data, results were taken from a new SIS frequency multiplier that has recently been developed at the Chalmers University of Technology. Previously, these experimental results were compared to simulations based on Tucker theory. Here, we compare these results to spectraldomain simulations. Qualitatively, the inclusion of embedding impedances and the use of spectral-domain analysis improves the agreement between simulation and experiment. The software can now be used to design multipliers with high output power and high conversion efficiency.A 230 GHz Finline SIS receiver with wide IF bandwidth
27th International Symposium on Space Terahertz Technology, ISSTT 2016 International Symposium on Space Terahertz Technology (2017)