363 research outputs found
Electronics, music and computers
technical reportElectronic and computer technology has had and will continue to have a marked effect in the field of music. Through the years scientists, engineers, and musicians have applied available technology to new musical instruments, innovative musical sound production, sound analysis, and musicology. At the University of Utah we have designed and are implementing a communication network involving and electronic organ and a small computer to provide a tool to be used in music performance, the learning of music theory, the investigation of music notation, the composition of music, the perception of music, and the printing of music
Novel Approaches to the Design of Phased Array Antennas.
This dissertation presents three new approaches to the design of phased array antennas in order to reduce their complexity. The first approach is based on extended resonance technique which, unlike conventional phased array designs, achieves power dividing and phase shifting tasks within a single circuit. A new extended resonance circuit is developed here that increases the maximum achievable scan angle by three times compared to the extended resonance phased array demonstrated previously. In order to expand the size of phased array, a new modular approach is used enabling a scalable design of extended resonance phased array for the first time. By applying heterodyne-mixing concept, a modular 24 GHz phased array has been demonstrated.
The second approach presented in this dissertation is based on a bi-directional feeding method. A new phased array is designed based on this approach which demands less phase shift from phase shifters compared to any of common phased arrays. The new bi-directional phased array allows for beam steering using only a single control voltage. A general design procedure for a bidirectional N-element phased array feed network is presented for the first time which allows applying this approach to phased arrays with any number of antenna elements. Furthermore, a new, compact phase shifter is designed and utilized in the phased array. A 2.4 GHz bi-directional phased array has been designed and fabricated.
Finally, the third approach described in the dissertation allows the phase progression across the antenna elements to be controlled by using a single phase shifter. Therefore, the number of phase shifters required in the phased array is substantially reduced compared to conventional phased array designs which require a separate phase shifter per each antenna element. A variable phase shift is achieved in this approach by vector summation of signals. The amplitude ratios of these vectors are adjusted to provide a linear phase progression. This approach is much simpler than the traditional Cartesian phase shifting scheme. A 2 GHz phased array designed based on this approach has been fabricated and tested.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89713/1/danial_1.pd
Passive and active circuits in cmos technology for rf, microwave and millimeter wave applications
The permeation of CMOS technology to radio frequencies and beyond has
fuelled an urgent need for a diverse array of passive and active circuits that address the
challenges of rapidly emerging wireless applications. While traditional analog based
design approaches satisfy some applications, the stringent requirements of newly
emerging applications cannot necessarily be addressed by existing design ideas and
compel designers to pursue alternatives. One such alternative, an amalgamation of
microwave and analog design techniques, is pursued in this work.
A number of passive and active circuits have been designed using a combination
of microwave and analog design techniques. For passives, the most crucial challenge to
their CMOS implementation is identified as their large dimensions that are not
compatible with CMOS technology. To address this issue, several design techniques –
including multi-layered design and slow wave structures – are proposed and
demonstrated through experimental results after being suitably tailored for CMOS
technology. A number of novel passive structures - including a compact 10 GHz hairpin resonator, a broadband, low loss 25-35 GHz Lange coupler, a 25-35 GHz thin film
microstrip (TFMS) ring hybrid, an array of 0.8 nH and 0.4 nH multi-layered high self
resonant frequency (SRF) inductors are proposed, designed and experimentally verified.
A number of active circuits are also designed and notable experimental results
are presented. These include 3-10 GHz and DC-20 GHz distributed low noise amplifiers
(LNA), a dual wideband Low noise amplifier and 15 GHz distributed voltage controlled
oscillators (DVCO). Distributed amplifiers are identified as particularly effective in the
development of wideband receiver front end sub-systems due to their gain flatness,
excellent matching and high linearity. The most important challenge to the
implementation of distributed amplifiers in CMOS RFICs is identified as the issue of
their miniaturization. This problem is solved by using integrated multi-layered inductors
instead of transmission lines to achieve over 90% size compression compared to earlier
CMOS implementations. Finally, a dual wideband receiver front end sub-system is
designed employing the miniaturized distributed amplifier with resonant loads and
integrated with a double balanced Gilbert cell mixer to perform dual band operation. The
receiver front end measured results show 15 dB conversion gain, and a 1-dB
compression point of -4.1 dBm in the centre of band 1 (from 3.1 to 5.0 GHz) and -5.2
dBm in the centre of band 2 (from 5.8 to 8 GHz) with input return loss less than 10 dB
throughout the two bands of operation
Micro-Resonators: The Quest for Superior Performance
Microelectromechanical resonators are no longer solely a subject of research in university and government labs; they have found a variety of applications at industrial scale, where their market is predicted to grow steadily. Nevertheless, many barriers to enhance their performance and further spread their application remain to be overcome. In this Special Issue, we will focus our attention to some of the persistent challenges of micro-/nano-resonators such as nonlinearity, temperature stability, acceleration sensitivity, limits of quality factor, and failure modes that require a more in-depth understanding of the physics of vibration at small scale. The goal is to seek innovative solutions that take advantage of unique material properties and original designs to push the performance of micro-resonators beyond what is conventionally achievable. Contributions from academia discussing less-known characteristics of micro-resonators and from industry depicting the challenges of large-scale implementation of resonators are encouraged with the hopes of further stimulating the growth of this field, which is rich with fascinating physics and challenging problems
RF Measurement Techniques
For the characterization of components, systems and signals in the range of
microwave and radio-frequencies (RF) specific equipment and dedicated
measurement instruments are used. In this article the fundamentals of RF signal
processing and measurement techniques are discussed. It gives complementary
background information for the introduction to RF Measurement Techniques and
the Practical RF Course, which are part of the Advanced Accelerator Physics
training program of the CERN Accelerator School (CAS) and have also been
presented at the CAS 2018 Special Topic Course in Beam Instrumentation.Comment: 54 pages, contribution to the CAS - CERN Accelerator School: Beam
Instrumentation, 2-15 June 2018, Tuusula, Finlan
Microwave group delay equalizers
A survey of the present state of microwave group-delay
equalizers is presented. Based on this, a number of equalizers
for use at microwave and millimetric wave frequencies are
investigated, both theoretically and experimentally. A microwave
group-delay measuring equipment is described, and a comprehensive
treatment of possible sources of error presented
Integrated optomechanics and single-photon detection in diamond photonic integrated circuits
The development of quantum computers and quantum simulators promises to
provide solutions to problems, which can currently not be solved on classical
computers. Finding the best physical implementation for such technologies is an
important research topic and using optical effects is a promising route towards
this goal. It was theoretically shown that optical quantum computing is
possible using only single-photon sources and detectors, and linear optical
circuits. An experimental implementation of such quantum optical circuits
requires a stable, robust and scalable architecture. This can be achieved via
miniaturization of the optical devices in the form of photonic integrated
circuits (PICs). The development of a suitable material platform for such PICs
could therefore have a large impact on future technologies. Diamond is a
particularly attractive material here, as it naturally offers a range of
optically active defects, which can act as single-photon sources, quantum
memories, or sensor elements. Besides its excellent optical properties, diamond
also has a very high Young's modulus, which is important for optomechanics, and
can be employed for potentially fast and low-loss tuning of PICs after
fabrication. In this work, components for future quantum optical circuits are
developed. This includes the first diamond optomechanical elements, as well as
the first integrated single-photon detectors on a diamond material platform.
Diamond micromechanical resonators with high quality factors are realized and
their actuation via optical gradient forces and electrostatic forces is
demonstrated. The accomplished superconducting nanowire single-photon detectors
show excellent performance in terms of low timing jitter, high detection
efficiency, and low noise-equivalent power. Moreover, a novel scalable method
for PIC fabrication from high quality single crystal diamond is presented.Comment: PhD thesis at the department of physics of the Karlsruhe Institute of
Technology (KIT), Advisors: Prof. Dr. Martin Wegener and Prof. Dr. Wolfram
Pernice. 152 pages, 84 figure
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