Sixty-GHz integrated RF head Final report

Integrated 60.8 GHz RF receiver and low noise IF preamplifier developmen

MKID development for SuperSpec: an on-chip, mm-wave, filter-bank spectrometer

SuperSpec is an ultra-compact spectrometer-on-a-chip for millimeter and submillimeter wavelength astronomy. Its very small size, wide spectral bandwidth, and highly multiplexed readout will enable construction of powerful multibeam spectrometers for high-redshift observations. The spectrometer consists of a horn-coupled microstrip feedline, a bank of narrow-band superconducting resonator filters that provide spectral selectivity, and Kinetic Inductance Detectors (KIDs) that detect the power admitted by each filter resonator. The design is realized using thin-film lithographic structures on a silicon wafer. The mm-wave microstrip feedline and spectral filters of the first prototype are designed to operate in the band from 195-310 GHz and are fabricated from niobium with at Tc of 9.2K. The KIDs are designed to operate at hundreds of MHz and are fabricated from titanium nitride with a Tc of 2K. Radiation incident on the horn travels along the mm-wave microstrip, passes through the frequency-selective filter, and is finally absorbed by the corresponding KID where it causes a measurable shift in the resonant frequency. In this proceedings, we present the design of the KIDs employed in SuperSpec and the results of initial laboratory testing of a prototype device. We will also briefly describe the ongoing development of a demonstration instrument that will consist of two 500-channel, R=700 spectrometers, one operating in the 1-mm atmospheric window and the other covering the 650 and 850 micron bands.Comment: As submitted, except that "in prep" references have been update

Application of Maxwell-Wagner polarisation in monolithic technologies

Imperial Users onl

Microstrip Line Discontinuities Simulation at Microwave Frequencies

Microwave and Millimeter wave integrated circuits (MICs) have experienced a tremendous growth over the last 50 years. Microstrip line is one of the popular lines in these MICs. Due to the layout necessities, an electromagnetic wave that propagates down a microstrip line may encounter discontinuities such as T-junctions, Bends and vias. A simulation model is presented here for analysing these discontinuities in microstrips through Sonnet Software. The parameters of microstrip lines are determined from the empirical formulae which are based on full wave analysis. The simulation work has been performed on Alumina substrate. The discontinuities are simulated and compensated which gives important results for designing high frequency microwave circuits. Key Words: Microwave and millimeter wave integrated circuits (MICs), microstrip line, microstrip line discontinuities, T-junctions, bends, steps in width, full wave analysis, substrate permittivity and sonnet software

High-frequency characterization of embedded components in printed circuit boards

The embedding of electronic components is a three-dimensional packaging technology, where chips are placed inside of the printed circuit board instead of on top. The advantage of this technology is the reduced electronic interconnection length between components. The shorter this connection, the faster the signal transmission can occur. Different high-frequency aspects of chip embedding are investigated within this dissertation: interconnections to the embedded chip, crosstalk between signals on the chip and on the board, and interconnections running on top of or underneath embedded components. The high-frequency behavior of tracks running near embedded components is described using a broadband model for multilayer microstrip transmission lines. The proposed model can be used to predict the characteristic impedance and the loss of the lines. The model is based on two similar approximations that reduce the multilayer substrate to an equivalent single-layer structure. The per-unit-length shunt impedance parameters are derived from the complex effective dielectric constant, which is obtained using a variational method. A complex image approach results in the calculation of a frequency-dependent effective height that can be used to determine the per-unit-length resistance and inductance. A deliberate choice was made for a simple but accurate model that could easily be implemented in current high-frequency circuit simulators. Next to quasi-static electromagnetic simulations, a dedicated test vehicle that allows for the direct extraction of the propagation constant of these multilayer microstrips is manufactured and used to verify the model. The verification of the model using simulation and measurements shows that the proposed model slightly overestimates the loss of the measured multilayer microstrips, but is more accurate than the simulations in predicting the characteristic impedance

Multi-chip module interconnections at microwave frequencies: electromagnetic simulation and material characterisation

In this work both the interconnections and materials used in multi-chip modules (MCMs) at microwave frequencies have been investigated. The electrical behaviour of the interconnections was studied using commercially available 2.SD and 3D electromagnetic simulators (HFSSTM, MDSTM and Momentum™). State-of-the-art conductive and dielectric film materials used in the fabrication of multi-layer MCM structures were characterized using microstrip/wave guide resonator techniques. The models chosen for simulation of interconnections are commensurate with those in current use in MCM technology. Crosstalk between microstrip conductors in multi-layer MCM structures was simulated and new knowledge leading to new design rules was obtained.Typical elements in MCM interconnect structures, such as vias, bends and airbridges were also investigated. The principal features of these elements were simulated and the results were obtained in S-parameter form. Based on the simulated results, these parasitic elements were modelled in terms of their equivalent circuits which can be used in circuit simulators to aid more rigorous MCM circuit design. A microstrip ring resonator, fabricated using the newly developed conductive material from Heraeus, was employed to measure the line loss. New techniques have been developed to measure the permittivity and loss tangent of thin dielectric films. In the previous methods for the measurement of these films, the accuracy in measuring the relative permittivity is limited and there is no available technique to measure the loss tangent. A novel cavity perturbation method was developed to accurately measure both the relative permittivity and loss tangent of the films deposited on a supporting substrate. An additional independent technique, derived from transmission line theory, for measuring the relative permittivity of dielectric film was also established. A particular feature of the new teclmiques, which led to high accuracy in measuring dielectric constant and loss tangent was the positioning of the dielectric film in the region of maximum electric field strength, thereby ensuring maximum interaction between the electric field and the film material. A rigorous error analysis was performed on the new techniques, which led to the establishment of practical measurement correction factors. A simple and rigorous method has also been developed to accurately measure the loss tangent of dielectrics with known dielectric constant using a resonant cavity. The novel method eliminates the need for any physical measurement of the dielectric sample. The new technique should permit the development of techniques for very high frequency characterisation of dielectric materials

A study of microwave downcoverters operating in the K sub u band

A computer program for parametric amplifier design is developed with special emphasis on practical design considerations for microwave integrated circuit degenerate amplifiers. Precision measurement techniques are developed to obtain a more realistic varactor equivalent circuit. The existing theory of a parametric amplifier is modified to include the equivalent circuit, and microwave properties, such as loss characteristics and circuit discontinuities are investigated