Wireless, RF & Smart Dust

Research that includes:

  • Tuneable RF components: capacitors, inductors, transformers
  • RF microrelays
  • High frequency MEMS resonators: devices, structures, and processes

BPN597: QES: Design and Optimization of Passive Wireless Implantable Pressure Sensors

Neel K. Shah
Mozziyar Etemadi
Rishi Kant

Inductor design for passive wireless implantable use presents several challenges not currently addressed. A small form factor is desired for minimally invasive implantation and monitoring, and a low frequency is necessary for effective through-body power transfer. However a small inductor area limits effective power transfer and low-frequency operation. It is thus necessary to optimize the inductor for maximal power transfer while satisfying tight area and low frequency constraints. We present a design methodology for planar circular spiral inductors used with capacitive pressure...

BPN358: Micromechanical Transmit Filter

Li-Wen Hung

The ever-increasing appetite for wireless interconnectivity is beginning to drive new functions, like frequency gating spectrum analysis, that in turn drive a need for GHz resonators with si-multaneous high Q (>30,000) and low impedance (<200 Ohm). No single on-chip resonator device can deliver such performance in this frequency range to date. To achieve simultaneous high Q and low impedance, either the impedance of capacitive resonators must be lowered, or the Q's of piezoelectric resonators must be raised. This project investigates methods for increasing quality factor of...

BPN470: Low Power All-Digital Transceiver for Wireless Sensor Network

Richard Y. Su

Radios available today are designed to be high performance devices, and they consume about 30mW (CC1101). We would like to demonstrate an all-digital transceiver using only standard cell library components. This new design paradigm will focus mainly on low cost, ease of design, portability, and also decent performance. This transceiver will operate somewhere between 50 MHz and 1000 MHz, and it will have reasonable sensitivity and wide-band linearity across this band with low power consumption. No passive components, except for capacitors, will be used. The goal of this is to develop...

BPN607: Long-Term Stability in MEMS-Based Oscillators

Brian Pepin

The objective of this project is to accurately determine long-term frequency stability (i.e. frequency aging) of small-gap capacitive micro-electro-mechanical (MEMS)-based oscillators. This will be accomplished by creating a measurement setup where the oscillator is in a completely stabilized environment, the resonator is hermetically sealed into a clean enclosure, a “burn-in” is completed step to pre-age the device, and other precautions are taken as necessary for a detailed study of the aging process.

Project end date: 02/05/12

BPN613: High-Order UHF Micromechanical Filters

Turker Beyazoglu
Henry Barrow

The use of MEMS-based resonators for frequency filtering has been promising for achieving single- chip superheterodyne transceivers. For use in communications, filters having large out-of-band rejections and sharp rolloffs are required which necessitates their high-order implementation, yet filters having more than 3 resonators have not been achieved due to their high susceptibility of passband distorting effects. This project aims to realize higher order micromechanical filters to achieve better selectivity and stopband rejection at UHF range.

Project end date: ...

BPN477: OpenWSN: Open-Source Standards-Based Protocol Stacks for Wireless Sensor Networks

Thomas Watteyne

We are building a multi-platform, multi-operating system, fully standards-compliant interoperable wireless sensor network stack. Major standardization bodies have been looking at how wireless multi- hop networks should operate reliably (IEEE 802.15.4E, IETF RPL), how they can integrate within the Internet (IETF 6LoWPAN), and how utilities and end users should interact (OpenADR). All of these standards are being finalized. The OpenWSN project aims at federating these standards into a fully- functional protocol stack, at implementing these on a number of hardware and software platforms...

BPN369: HEaTS: AlN Narrowband RF Filters

Ernest Ting-Ta Yen

The long-term objective of this project is to realize self-temperature compensating narrow band filter bank for wireless communication systems. In this work, post-CMOS compatible aluminum nitride (AlN) RF Lamb wave resonators (LWR) are used as building blocks. LWR have the advantages of permitting multi-frequency devices with high Q (~3000) and low motional resistance (~100ohm). Different approaches including overhang adjustment are used to finely select the resonance frequency of LWR. Successful testing in high temperature up to 600C opens the potential applications of AlN resonator...

BPN542: New Materials for MEMS Resonators

Robert Schneider

New resonator structural materials will be explored to achieve GHz-frequency MEMS resonators having ultra-high quality factors (Q's) and antenna-amenable motional impedances. Materials having acoustic velocities greater than that of polysilicon, such as diamond and silicon carbide (SiC), will be used to fabricate devices having higher resonance frequencies and higher Q's than their polysilicon counterparts. Low-loss metals, including metal alloys, will be investigated to achieve low deposition temperatures and high electrical conductivities while nonetheless maintaining high Q's....

BPN624: The Internet of Things: IPv6 for Multihop Wireless Sensor Networks

Branko Kerkez
Fabien J. Chraim

The Internet of Things enables great applications, such as energy-aware homes or real-time asset tracking. With these networks gaining maturity, standardization bodies have started to work on standardizing how these networks of tiny devices communicate. We strongly believe IEEE802.15.4e TSCH is the most reliable and energy-efficient MAC protocol for low-power motes. The goal of this project is to provide open-source implementations of a complete protocol stack based on the finalized Internet of Things standards. This implementation can then help academia and industry verify the...

BPN630: Capacitive-Gap Micromechanical Local Oscillator At GHz Frequencies

Tristan O. Rocheleau
Thura Lin Naing

This project aims to build a MEMS-based on-chip reference oscillator at GHz frequencies. By constructing an array of capacitive transduced micromechanical resonators with extremely small capacitive gaps and high mechanical Q, in conjunction with a low-power CMOS ASIC amplifier, it becomes possible to achieve self-sustained oscillation in a die-level system. The high mechanical Q of these devices, which can reach an extraordinary >40,000 at frequencies up to 3GHz, allows the possibility for unprecedented phase noise performance. Many applications for such high-frequency, low phase-...