2014 ESL Short Courses
Wednesday, August 6, 2014
Adaptive Antenna for GNSS Receivers: 8:30 am – noon
GNSS receivers are vulnerable to radio frequency interference. One can use signal processing techniques, e.g. FIR filters, frequency domain excision, etc. to suppress the interfering signals. Spatial processing using adaptive antenna, however, has become the universal choice for suppression of radio frequency interference in GNSS receivers. An adaptive antenna consists of multiple antenna elements. The signals received by various antenna elements are weighted and summed to produce a common output signal (for a given satellite signal frequency band) for all GNSS satellites in view or individual signal for each satellite in view. The element weights are calculated in real time and depend on the radio frequency environment. There are many approaches to calculate the antenna element weights. Thus, the performance of an adaptive antenna not only depends on the physical characteristic (size, number of elements and distribution of elements, etc.) of the antenna array but also depend on the weighting algorithm. In this short course, we will discuss the various parameters that affect the performance of GNSS adaptive antennas. The performance metrics will include C/N as well as antenna induced biases in GNSS receiver measurements.
Design and Operation of UWB Antennas: 8:30 am – noon
Ultra-wideband (UWB) antennas are desirable for supporting modern software-defined radios and software-defined radars, as well as advanced coding and waveforms. These advanced technologies have been developed for achieving higher data rates, more secured channels, and better accuracy via spectrum agility, spectrum diversity, and wide bandwidth. Using a single UWB antenna in place of multiple co-located narrowband antennas also avoids performance degradations related to absorption and scattering from adjacent antennas, as well as reduces cost, maintenance, inventory, and visibility. Designing an UWB antenna requires careful consideration of radiation mechanisms and performance tradeoffs in order to obtain desired gain, pattern, and impedance performance at all frequencies. This half-day course will cover: definition of UWB antennas, classification of UWB antennas, UWB antenna design guidelines, and design examples of UWB antennas.
A Tutorial on Designing Wideband Tightly-Coupled Phased Arrays: 1:30 pm – 5 pm
Tightly coupled phased array (TCPA) antenna designs differ from conventional phased array antenna design in that strong inter-element coupling is utilized to achieve multiple octaves of bandwidth with and without the presence of ground plane backing. This tutorial will cover: step-by-step instructions of designing a generic TCPA design, insightful discussions about the causes of performance issues associated with low-angle beam steering in phase arrays, and design examples of generic wideband & wide beam steering TCPA antennas.
Integrated Photonics: 1:30 pm – 5 pm
Integrated photonics encompasses the science and engineering of optical guided waves in highly integrated devices, components, circuits, and systems in a manner that is analogous to integrated circuits in electronics. The chip-scale control of light in planar optical waveguides enables processing and routing of data in the optical domain, offering size, weight, and power consumption advantages, compared to electronic solutions, especially at increasingly high data rates. This short course introduces the fundamentals of integrated photonics with an emphasis on silicon photonics. Fundamental building blocks will be discussed including waveguides, modulators, filters, couplers, resonators, switches, multiplexers, and detectors. Efficient fiber-to-chip couplers will also be covered. Applications in telecommunications, interconnects, sensors, and radio-frequency (RF) photonics will be discussed throughout the course within a theoretical and experimental context.
Thursday, August 7, 2014
Cognition and Radar Sensing: 8:30 am – noon
The application of cognitive signal processing to radar sensing has enormous potential to improve the performance of current systems, as well as opening up new applications, particularly those requiring autonomy. In this short course, the need for cognition in radar sensing is established along with the ingredients necessary for true cognition. Human cognition is used as an accessible and pertinent example from which artificial forms may be derived and applied to radar sensors.
The lessons learned are applied to the design of new forms of radar processing architecture and processing methodologies. A new processing concept for radar exploiting echoic flow fields is introduced as an example of a cognitive processing concept that links perception and action through decision making.
This concept offers a power basis for autonomous applications such as navigation, automatic landing, docking and vehicle collision management.
Antenna-to-Antenna Coupling on Aircraft: 8:30 am – noon
Predicting the coupling between multiple antennas mounted on realistic aircraft platforms is a challenging EMI/EMC problem due to the large platform size and the complexity of modern antenna arrays. This short course will define the coupling parameters of interest to the systems engineer, and discuss analytical ray-based methods and numerical methods for calculating and understanding coupling mechanisms. Approaches are also presented for characterizing an antenna separately from the aircraft, including large phased arrays and conformal arrays, and then predicting the performance when mounted on the aircraft.
Radio Frequency Propagation over the Sea Surface: Mechanisms & Models: 1:30 pm – 5 pm
Caglar Yardim & Fernando Teixeira
Non-standard propagation in Earth’s atmosphere can play an important role in radar and communications system design, particularly for systems operating at sea. The ducting propagation mechanism can cause changes in radar system performance, including the presence of coverage “holes” or extended detection ranges. The ducting mechanism depends on meteorological properties, so that understanding and forecasting ducting effects involves coupling electromagnetic and geophysical information. This short course will introduce the basic physical mechanisms of ducting propagation, and will describe the standard techniques used to describe the related atmospheric properties and to forecast the impact on radio frequency propagation. Recent developments in the use of radar measurements to remotely sense the atmospheric state will also be presented. Current research activities at the ElectroScience Laboratory involving both measurements and models for ducting propagation will also be presented.
Bio-Inspired Radar Design: 1:30 pm – 5 pm
Bats, whales and dolphins are all examples of echolocating mammals that depend on active sensing of their environments for their survival. The echolocating bat has evolved a remarkably high level of capability fine tuned over a period of more than 50 million years. There are also examples of humans who are expert in echolocation in which they not only detect targets but can recognize them with a remarkable degree of fidelity. This short course begins by examining the methods used by the echolocating bat and draws lessons for the design and operation of radar systems. Specifically, the waveforms and strategies used by bats for detection and classification are introduced and put into a radar context. It is shown how they are able to use a combination of waveform diversity and self-orientation to navigate autonomously, to detect and distinguish prey from clutter. Examples, applying these bio-inspired concepts in radar systems are also given. The course then goes on to look at human echolocation, studying the relationship between transmitted waveforms and the ability to distinguish differing shaped objects. In this way, lessons for the design of future radar systems are examined.
Friday, August 8, 2014
Passive Radar: 8:30 am – noon
Passive radar is currently a hot topic with commercial systems starting to appear as well as a wealth of research being conducted by many of the leading laboratories around the world. It is a rapidly maturing technology showing great promise for a range of applications, especially those requiring air target detection and tracking. New modes of operation such as imaging and MIMO are also possible. Passive radar exploits emissions of opportunity to form an RF sensor. It is covert, can counter stealth technology and is inherently low cost. Passive radar also is both frequency and space diverse. Further, an increasingly congested spectral environment is set to continue to improve passive radar performance for the foreseeable future. This short course introduces the principles and practice of passive radar from basic principles, conceptual design, processing methods for detection, tracking and imaging as well as hardware requirements. Examples from full-scale experimentation are used throughout to illustrate achievable performance. Latest developments in imaging and use of wideband signals are also included.
RFIC Architectures and Design for Radar and Communication Systems: 8:30 am – noon
Waleed Khalil & Brian Dupaix
The surge in demand for high performance and low cost wireless circuits has accelerated the shift to CMOS RFIC technology. As future wireless radios continue to push the available bandwidth and shift to mm-wave range, RF CMOS is expected to remain the predominant technology. This full day course will cover in depth the practical aspects of CMOS RF design at both the circuit and device level. The course will begin by an overview of the CMOS transistor and passives from RF perspective, analyzing key concepts in modeling and noise behavior. An overview of various RF circuit blocks highlighting design architectures and circuit implementation tradeoffs will be provided. The course will provide insightful guidance in the circuit design process including transistor sizing, layout effects, parasitic reduction techniques and tradeoffs between various circuit topologies.