Kartikeya Mayaram - US grants

This research explores methods and techniques for a design and simulation environment with the target application being high performance and high frequency communication circuits. Within the simulation environment a designer will have access to a suite of models of varying accuracy and to analysis capabilities that address the needs of high frequency design. The analysis capabilities include periodic-steady state solution for RF circuits, calculation of noise and distortion in the periodic-steady state, substrate coupling and electrothermal interactions. The research is partitioned into three areas: (i) development of new analysis capabilities for an integrated device-circuit- behavioral simulation environment; (ii) improvement of simulator performance so that it is valuable to designers of high performance and/or high frequency analog circuits, and (iii) application of the simulator to realistic design problems with particular emphasis on RFICs. A virtual lab environment is being developed to provide students training in circuit/device simulation and tool development with applications to real life design examples.

ABSTRACT EEC-9708324 Ringo The performance of submicron CMOS components like transistors, resistors and capacitors are usually limited by the parasitic substrate elements. Past processing micromachining techniques can be employed to physically remove the cause of some of these parasites. This three-year continuing award will study the development of micromachining techniques to enhance the performance of mixed-signal circuits in a submicron CMOS technology. During the first two years, a set of primitive devices will be developed using an advanced micromachining process to be performed at the Washington Technology Center. The devices will be characterized to determine design rules and device models suitable for mixed-signal circuit simulation. In the second and third year, primitive circuit blocks will be built to determine reliability and characterize the improvement in the circuit operation. Research results will include the design rules and the specification necessary for the two past processing micromachining techniques developed to eliminate parasitic substrate elements.

The goal of this Engineering Microsystems: "XYZ" on a Chip project is to investigate the fabrication of a micro heat engine, which will use commonly available liquid hydrocarbon fuels, to efficiently generate electric power to be used by Micro-Electro-Mechanical Systems (MEMS) and microelectronic devices. This micro heat engine is expected to deliver electric power in the range of milliwatts to watts while supplying voltages from 1 to 30 volts. The research involves the creation of a totally new class of heat engine, which takes advantage of thermophysical phenomena unique to small scales.

The result will be a heat engine that is efficient and that can be mass-produced with techniques developed for microelectronics and MEMS. The proposed engine is an external combustion engine, in which thermal power is converted to mechanical power through the use of a novel thermodynamic cycle which approaches the ideal vapor Carnot cycle. Mechanical power is converted into electrical power through the use of a piezoelectric generator. The generator, which takes the form of a flexible membrane, can be readily manufactured using MEMS fabrication techniques but still delivers high conversion efficiency. This approach eliminates the requirement to manufacture complex micromachines such as rotary compressors and turbines, resulting in a very simple but highly efficient device. In addition, since the micro heat engine is an external combustion device, it will have broad fuel flexibility, making it useful in a wide range of applications including military, space, biomedical, and consumer products.

With the proliferation of RF ICs in consumer electronic products there is a critical need for simulation and modeling tools that enable first pass success in silicon. The trend towards integrating complete systems on a chip, requires very high performance digital, analog, and RF circuits to be integrated on the same silicon substrate. Successful integration of these complex systems requires new design tools and design approaches that significantly advance the state-of-the-art. Certain aspects of RF system performance are easier to characterize and verify in steady state. Examples of these are distortion, power, frequency, noise, and transfer characteristics such as gain and impedance. The proposed work focuses on developing a coupled device and circuit simulator that will accurately address the modeling and simulation needs of critical and noise sensitive analog and RF devices and circuits. A coupled device and circuit simulator provides a
direct link between the IC fabrication technology, device design and the higher level of circuit design. Since the models from the device simulator (numerical models) are predictive, they can be used to evaluate the impact of technology on circuit performance. Additionally, this work provides the foundation for new design approaches that will advance the state-of-the-art for analog and RF circuits blocks.

This research will focus on modeling, simulation, and design of high performance and high frequency analog and RF circuits. The key contributions of this work will be:

A software architecture for incorporating general purpose device simulators in the coupled device and circuit simulator CODECS. The architecture will allow integration without extensive modifications to the device simulator and enable simulation of technologies such as SiGe and SOI, and also simulation of optical devices. This tool architecture also facilitates parallelization over a cluster of workstations.

Availability of time-domain and frequency-domain steady-state simulation methods within one simulator. Numerical (physical) models and compact circuit models can be used within this simulator.

Capability of simulating device-to-device interactions including substrate and thermal couplings.

Coupled device and circuit noise simulation techniques for RF circuits.

Validation of simulator with fabrication of improved designs for the following RF circuitry: low noise amplifier (LNA), mixer, and voltage controlled oscillator (VCO). These circuits are critical blocks in a transceiver and are particularly sensitive to noise.

The research in this proposal is tightly integrated with a significant educational
component. This will include development of courses in RF integrated circuits, and modeling and simulation for RF applications. A new undergraduate course will be developed. This course will focus on transceiver architectures and discrete design and will include a lab in which students will gain hands-on experience in radio design. The emphasis will be on projects related to transceiver design. The research results, including the software, circuit designs, and course-related materials will be available on the world wide web. In addition, results from the proposed work will be presented at meetings of the Semiconductor Research Corporation and the NSF Center for Design of Analog and Digital ICs.

Radiation reliability of semiconductor devices is an important area of concern with the rapid growth in the number of satellites launched for military and commercial space-applications. Given the high cost of launching and maintaining a satellite-base resource, it is very important to give a careful consideration of the reliability of the sophisticated electronic systems on board the satellite. Similarly, all the electronic systems, especially the safety equipment used in nuclear reactor and weapon environment must operate reliably even in the case of an accidental exposure of the equipment to a burst of neutrons.

Radiation effects in silicon devices have been studied extensively. In comparison, the current knowledge of radiation effects in III-V compound semiconductor (e.g. GaAs) based heterostructure devices is very limited. It is well known that these devices exhibit superior performance especially at higher speeds/frequencies than the conventional silicon devices. Hence, increasing numbers of GaAs and related III-V compound semiconductor devices are being used in satellite-based high speed communication systems.

The objective of this project is to conduct research on the radiation effects in two important types of heterostructure devices: (a) High Electron Mobility Transistors (HEMTs) and (b) Heterojunction Bipolar Transistors (HBTs). Both types of devices are extensively used in a number of GaAs RF circuits and high-speed digital integrated circuits. The following three different types of radiation sources will be used in this investigation: (1) protons (2) electrons and (3) neutrons. The current status of our knowledge on the effects of the above types of radiation on the devices of interest and the specific details of the work to be conducted are discussed in the main body of the proposal.

Some key elements of research issues addressed in this program are:

o Conduct experimental investigations of the characterization of the radiation-induced defects in the different layers of the device and the performance degradation of the devices (HEMTs and HBTs) under different types of radiation.
o Develop a systematic understanding of the relationship between the characteristics of radiation-induced defects, the basic mechanisms and degradation of the performance of the devices.
o Develop a complete model for the prediction of device degradation in actual radiation environment given the knowledge of the radiation-induced defects in the constituent materials of the device structure.

A major impact of this research plan will be on the development of new device/circuit designs for greater reliability against radiation effects. The proposed program will also educate a new generation of device engineers with specialized skills in the design, fabrication and analysis of advanced heterostructure devices meant for applications in radiation environment. This is expected to result in advanced III-V compound semiconductor devices with improved radiation reliability.

This award supports the development of a miniature radio tag capable of communicating with cell tower receivers normally used by cellular phones. The device is essentially a stripped-down version of a cell phone with low enough mass (2 grams) to permit its attachment to migratory birds or other small animals. To conserve power, a timer in the unit will keep it dormant until preprogrammed dates when the transmitter will activate and attempt to make contact with a nearby cell phone tower. Because the device will remain off during an extended period, and then activate for only long enough to make contact with the nearest receiver, a tiny battery is expected to provide sufficient power for several contacts over a period as long as 2 years. Each unit will communicate a unique identifying number, so that individual tagged birds can be linked to a specific location. Following the contact, the PI will receive notification of the tag identity and location from the cellular network provider by email. The tag will be useful in studies of migration and dispersal, both of which are nearly universal behaviors among animals, particularly birds. Despite their importance, the impact of these behaviors on population dynamics remain major unanswered questions in biology, in large part because of our inability to track Individual animals throughout their annual cycle. The strategy is expected to locate birds to within a 5 km radius, a completely unprecedented level of precision for locating individual small migratory animals. The project is a collaboration of ecologists and electrical engineering researchers that will involve undergraduate and graduate students in collaborative learning opportunities, including both design and field testing of the instrument.

This Partnerships for Innovation (PFI) project--a Type III (C:A) partnership between Oregon State University (OSU), an institution new to the PFI Program (defined as one that has never been a PFI grantee), and Portland State University, an NSF PFI graduate (0438736--seeks to build upon the Oregon Commercialization Initiative (OCI), a pilot program which is underway, in order to catalyze commercialization efforts in Oregon by leveraging lessons learned and existing assets such as the Oregon Nanoscience and Microtechnologies Institute (ONAMI) so as to create a broader program with greater impact. ONAMI and OTRADI are resources for the "physical" and "technical" aspects of commercializing an invention; they enable the building and testing of prototypes. The development and implementation of a plan that brings an invention to market needs an additional resource, the intervention of experienced business entrepreneurs. OSUs model for screening and incubating new business opportunities from laboratory concepts addresses many of the roadblocks associated with university commercialization. One of the features of the model is the early direct involvement of seasoned entrepreneurs. Indeed, the full panoply of pertinent non-academic players are to be brought onto the university campus and protocols for interaction with, and education of researchers, students, and administrators will be implemented, studied, and further developed. So far, more startups have been created in the two years of the pilot program than had been created in the history of OSU.

OCI will accelerate the development of an entrepreneurial culture at several research universities. The research team and business students will study the impact of OCI and publish their findings. Thus OCI will advance discovery and understanding while promoting teaching, training, and learning. OCI will enhance the infrastructure for research and education by supporting the efforts of researchers to commercialize their discoveries. In so doing, it will enable the Oregon universities to recruit and retain better students and better professors. The proposed activity will benefit society by generating jobs, creating wealth, and improving both the standard of living and the quality of life in the Pacific Northwest. OCI will create tool kits which will enable universities to replicate its achievements in other regions.

Partners at the inception of the project are Academic Institutions: Oregon State University (OSU) (lead institution), Portland State University (PSU), Willamette University, University of Oregon, Arizona State University, University of Washington, and University of Utah; Private Sector Organizations: Bend Research Inc.; Buerk Dale Victor LLC; Hewlett-Packard; Intel; Marger, Johnson & McCollom, P.C.; Northwest Technology Ventures, LP; Oregon Entrepreneurs Network (OEN); and The Partners Group; Preston, Gates & Ellis LLP; and Public Sector Organizations: Oregon Nanoscience and Microtechnologies Institute (ONAMI), and Oregon Translation Research and Drug Development Institute (OTRADI).