Wireless, RF & Smart Dust

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...

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...

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-...

There has been recent interest in low noise mm-wave signals for satellite data communication and RADAR. For these applications, close in to the carrier phase-noise performance is important. Several competing very-low-phase-noise oscillator technologies exist at lower microwave frequencies. All of these face difficulties in being extended up to the new bands of interest. We propose using an optical frequency comb generator together with an optical interleaver to up convert the low noise, low frequency microwave signal to the desired high frequency bands without increasing the phase...