Jonathan Roderick

An Integrated Ultra-Wideband Timed Array Receiver in 0.13

A fully integrated CMOS ultra-wideband 4-channel timed array receiver for high-resolution imaging application is presented. A path-sharing true time delay architecture is implemented to reduce the chip area for integrated circuits. The true time delay resolution is 15 ps and the maximum delay is 225 ps. The receiver provides 11 scan angles with almost 9 degrees of spatial resolution for an antenna spacing of 3 cm. The design bandwidth is from 1 to 15 GHz corresponding to less than 1 cm depth resolution in free space. The chip is implemented in 0.13 mum CMOS with eight metal layers, and the chip size is 3.1 mm by 3.2 mm. Measurement results for the standalone CMOS chip as well as the integrated planar antenna array and the CMOS chip are reported.

\mu{\hbox{m}}

Ultra-wideband (UWB) beam-forming, a special class of multiple-antenna systems, allows for high azimuth and depth resolutions in ranging and imaging applications. This paper reports a fully integrated UWB beam-former featuring controllable true time delay and power gain. Several system and circuit level parameters and characterization methods influencing the design and testing of UWB beam-formers are discussed. A UWB beam-former prototype for imaging applications has been fabricated with the potential to yield 20 mm of range resolution and a 7deg angular resolution from a four-element array with 10 mm element spacing. The UWB beam-former accomplishes a 4-bit delay variation for a total of 64 ps of achievable group delay with a 4-ps resolution, a 5-dB gain variation in 1-dB steps, and a worst case -3-dB gain bandwidth of 13 GHz. Overall operation is achieved by the integration of a 3-bit tapped delay trombone-type structure with a 4-ps variable delay resolution, a 1-bit, 32-ps fixed delay coplanar-type structure, and a variable-gain distributed amplifier. The prototype chip fabricated in a 0.18 mum BiCMOS SiGe process occupies 1.6 mm2 of silicon area and consumes 87.5 mW from a 2.5-V supply at the maximum gain setting of 10 dB

CMOS Using a Path-Sharing True Time Delay Architecture

This article covers the basic principles of true-time-delay (TTD)-based space-time array processors and ultra-wideband beamformers. General considerations regarding the need for TTD array processing, optimum array size, antenna spacing, and array patterns are discussed for communication and imaging UWB arrays. Several recent integrated circuit implementations of UWB TTD-based beamformers are presented. A few commercial applications that warrant UWB TTD-based array processing, with emphasis on imaging and sensing, are also described.

Silicon-Based Ultra-Wideband Beam-Forming

This paper presents a wireless non-contact sensor that enables detection, localization, and monitoring of people along with their specific features such as gait and cardiopulmonary activities. These types of sensors can be embedded in the environment and networked with the existing wireless infrastructure to create an intelligent and responsive ambient where the health of children, patients, and the elderly can be monitored without intrusion. None of the common sensing modalities including visible optical, infra-red, and ultra-sound can operate under different visibility conditions, without Line-Of-Sight (LOS), under environmental noise, and measure human-specific features simultaneously. Radio Frequency (RF) sensors have been used to localize humans, and monitor their gait and vital signs [1,2]. Most of these RF sensors transmit a Continuous Wave (CW) modulated or un-modulated waveform and detect the Doppler shift caused by the movement of hearts, lungs, and other body parts — the latter referred to as micro-Doppler technique. RF sensors do not require LOS and work under extreme weather and visibility conditions.

Integrated true-time-delay-based ultra-wideband array processing

The increased interest in Ultra-WideBand (UWB) impulse-based systems for high-resolution imaging applications [1] has created a demand for medium-power linear amplifiers capable of transmitting such signals (FCC limits peak EIRP to 18dBm for UWB signals with 3GHz bandwidth). An integrated CMOS power amplifier (PA) with the ability to transmit arbitrary instantaneous UWB waveforms has significant value in realizing a completely-integrated silicon UWB imaging transceiver. UWB radar and imaging systems that utilize waveforms occupying the FCC-allocated lower GHz frequency bands (960 to 3100MHz) are attractive for wireless search-and-rescue and see-through-the-wall sensing applications as well as within-the-wall imaging due to the lower electromagnetic attenuation of most materials at these frequencies. The main contribution of this paper is the realization of an integrated 0.13µm CMOS power amplifier that is suitable for signals with an ultra-wide instantaneous bandwidth. The UWB PA is compatible with previously-reported true-time-delay-based beam-forming systems for low-GHz high-resolution imaging applications [1].

A short-range UWB impulse-radio CMOS sensor for human feature detection

Design equations and performance limits of stacked Class-E power amplifiers at mm-waves, including the limitations imposed by device parasitics, are presented in this paper. As a proof of concept of this parasitic aware mm-wave Class-E design methodology and to demonstrate the beyond BVCEO Class-E operation in a stacked architecture at mm-wave frequencies, a Q-band, single ended, two-stage, double-stacked, Class-E power amplifier is designed in a 0.13 μm SiGe HBT BiCMOS process. The measured performance of the fabricated chip show 23.4 dBm maximum output power at 34.9% peak power added efficiency (PAE), and 14.6 dB of power gain across 5 GHz centered around 41 GHz for a supply voltage of 4 V. The total chip area including the pads is 0.8 mm × 1.28 mm.

A 0.13µm CMOS power amplifier with ultra-wide instantaneous bandwidth for imaging applications

This paper presents a radio frequency (RF) CMOS chip and algorithm integrated solution of an Ultra-Wideband (UWB) Impulse-Radio (IR) radar system for human presence detection and tracking. UWB radar can complement other human detection and tracking technologies, as it works well in poor visibility conditions with high time/depth-resolution. UWB radar response provides the complex multipath scattering characteristics in each scan, as well as the high sensitive variation in dynamic observation patterns between scans to pose challenge in designing UWB radar hardware and signal processing algorithm. We develop a UWB IR CMOS human feature detection radar transceiver chip and human presence detection algorithm. Thereafter, we integrated the UWB CMOS radar chip and the algorithm through UWB sensor module, and tested the integrated system in a simple outdoor environment to validate the performance of the integrated system. We present experimental results in which the integrated UWB human detection radar system tracks human and non-human targets, and detects human presence by discerning human from moving non-human objects robustly using human feature extraction and likelihood ratio testing (LRT).

Analysis, design and implementation of mm-Wave SiGe stacked Class-E power amplifiers

A fully integrated 4-channel UWB beam-former in 0.13μm CMOS uses a path-sharing true-time-delay architecture with 15ps resolution. The 3.1×3.2mm2 chip produces 11 different scanning angles within plusmn60deg with 10° spatial resolution for 25mm antenna spacing. The front-end achieves an NF of 2.9 to 4.8dB across 18GHz of BW with less than 5ps of group delay variation.

UWB human detection radar system: A RF CMOS chip and algorithm integrated sensor

A Q-band two-stage Class-E power amplifier is designed and fabricated in a 0.13 μm SiGe HBT BiCMOS process. A mm-wave Class-E architecture considering the effect of various interconnect parasitics is adopted to achieve high power efficiency. Proper input and output networks have been designed to enable efficient switching of the HBT at large voltage swings without causing unwanted impact ionization-induced negative base current and instability. The measured performance of the fabricated chip show 20.2 dBm maximum output power, 31.5% peak power added efficiency, and 10.5 dB power gain across 4 GHz centered around 45 GHz for a supply voltage of 2.5 V. The total chip area including the pads is 0.74 mm × 1.7 mm.

A 4-Channel UWB Beam-Former in 0.13μm CMOS using a Path-Sharing True-Time-Delay Architecture

This paper documents an ultra-wideband (UWB) fully integrated beamformer which features controllable true time delay and power gain. The UWB beamformer accomplishes 4-bit delay variation with 4 ps resolution, 5 dB gain variation in 1 dB steps, and a -3dB gain bandwidth of 11.2 GHz. Overall operation is achieved by the integration of a three-bit tapped delay trombone-type structure with 4ps variable delay resolution, a one-bit 32ps fixed delay coplanar-type structure, and a variable gain distributed amplifier. The prototype chip fabricated in a 0.18 mum BiCMOS SiGe process occupies 1.6mm2 of silicon area and consumes 125 mW from a 2.5 V supply at the maximum gain setting of 14.2 dB