Publications

We have developed and demonstrated a highduty- cycle asynchronous InGaAsP-based photon counting detector system with near-ideal Poisson response, roomtemperature operation, and nanosecond timing resolution for near-infrared applications. The detector is based on an array of Geiger-mode avalanche photodiodes coupled to a custom integrated circuit that provides for lossless readout via...

The energy-level structure of a quantum system, which has a fundamental role in its behaviour, can be observed as discrete lines and features in absorption and emission spectra. Conventionally, spectra are measured using frequency spectroscopy, whereby the frequency of a harmonic electromagnetic driving field is tuned into resonance with a...

A design method is presented for contiguous-channel multiplexing filters with many channels covering a wide bandwidth. The circuit topology extends previous work on cochlea-like channelizers by introducing multiple resonator-channel filter sections. The new design provides increased stopband rejection, lower insertion loss, and improved passband shape compared with the earlier version...

To enable development of novel signal processing circuits, a high-speed surface-channel charge coupled device (CCD) process has been co-integrated with the Lincoln Laboratory 180-nm RF fully depleted silicon-on-insulator (FDSOI) CMOS technology. The CCDs support charge transfer clock speeds in excess of 1 GHz while maintaining high charge transfer efficiency (CTE)...

This paper reports a demonstration of X-band receiver RF front-end components and the integrated chipset implemented in 0.18 mum silicon germanium (SiGe) technology. The system architecture consists of a single down conversion from X-band at the input to S-band at the intermediate frequency (IF) output. The microwave monolithic integrated circuit...

In this letter, we present a state-of-the-art, planar double-tuned transformer using high- , micromachined spiral inductors and integrated capacitors. This circuit provides a 4:1 impedance transformation over a 30% bandwidth centered at 4.06 GHz, with a minimum insertion loss of 1.50 dB. The fabricated circuit occupies a total area of...

Arrays of InP-based avalanche photodiodes (APDs) with InGaAsP absorber regions have been fabricated and characterized in the Geiger mode for photon-counting applications. Measurements of APDs with InGaAsP absorbers optimized for 1.06 um wavelength show dark count rates (DCRs)

Indirect modulation of fractional-N synthesizers is an energy-efficient architecture capable of moderate data rates, and is well-suited for use in sensor networks or WLAN. Although the architecture is used primarily at low RF frequencies, the capability for fractional- N synthesizers at Ku-band and above currently exist in available silicon technology...

This work presents the design and measurement of a 2Mbps BFSK transceiver at 1.35 to 1.75GHz for use in wireless sensor node applications. The receiver is a direct conversion architecture and has a sensitivity of -74dBm at 2Mbps and consumes 8.0mW. The transmitter generates orthogonal BFSK modulation through the use...

We demonstrated microwave-induced cooling in a superconducting flux qubit. The thermal population in the first-excited state of the qubit is driven to a higher-excited state by way of a sideband transition. Subsequent relaxation into the ground state results in cooling. Effective temperatures as low as ≈3 millikelvin are achieved for...