Hakon A. Hjortland

CTBV Integrated Impulse Radio Design for Biomedical Applications

Improving quality of service in wireless communication links is of vital importance in biomedical applications. Limitations of current technology are evident with a limited number of channels and prone to fading. In this paper, we are exploring impulse radio as a feasible technology for health monitoring and even as novel detached sensors. By exploring advanced deep submicron technology and novel architectures, improved quality of service may be granted. Additional interesting biomedical functionality of the impulse radio is detached body sensors (short-range medical radar).

Thresholded samplers for UWB impulse radar

This paper presents two novel methods for sampling the backscatter in an impulse radar system. The authors have called the two related methods for swept threshold and stochastic resonance sampling. The samplers are simple, mostly digital circuits which are not clocked, but instead utilize continuous-time signal processing. Since fine-pitch CMOS is not very good for analog processing, but instead has very fast digital logic, the samplers are well suited for this technology. An implementation in 90 nm CMOS is described and measurements which confirm a working 23 GHz sampler are shown

UWB Vivaldi antenna for impulse radio beamforming

In this paper, two different types of Vivaldi antenna are designed and tested suitable for electromagnetic beamforming. The first is an antipodal Vivaldi antenna, while the other is a tapered slot Vivaldi antenna. They are both ultra wideband antennas for the 1 GHz to 5 GHz frequency band. They have low impulse distortion and the voltage standing wave ratio (VSWR) less than 2 throughout the entire bandwidth. The antennas are used for impulse radio beamforming.

CMOS Impulse Radar

A novel CMOS impulse radar for CMOS implementation is proposed exploring the concept of swept-threshold sampling. Time-domain signal processing with counter-based integration in parallel structures is used. With continuous time delay line based parallel sampling topologies we achieve a sampling rate in excess of 20GHz. A functional CMOS impulse radar is implemented in silicon with measured system performance

A 5.2 pJ/pulse impulse radio pulse generator in 90 nm CMOS

A low-power impulse radio (IR) ultra wideband (UWB) pulse generator (PG) is presented. It uses digital gate-delay for timing achieving good power efficiency and acceptable spectral filling. The circuit is scalable in both bandwidth and center frequency. Both energy consumption and chip area are reduced compared to most conventional higher order Gaussian PGs. The PG is realized in a TSMC 90 nm CMOS process. Measurements show the energy consumption from a 1.2 V to be 5.2 pJ/pulse for a 200 MHz pulse repetition frequency (PRF). The core area is 0.0015 mm2 (38 µm×40 µm). Lastly, a dynamic pre-charge (DPC) scheme is proposed to eliminate the standby current and make the PG favourable for low-data-rate applications.

Power Harvesting Circuits in 90 nm CMOS

The purpose of this paper is to explore power harvesting capabilities in nanometer technology. Novel charge pump improvements using the back-gate or well of MOS devices improve efficiency as well as sensitivity. The proposed circuits are implemented in 90 nm CMOS. Measured performance will be provided.

Impulse Radio technology for Biomedical applications

Improving quality of service in wireless communication links is of vital importance in biomedical applications. Current wireless technology is far from satisfactory conveying vital signs in personalized healthcare. Nevertheless current technology like Bluetooth and ZigBee is explored even for critical monitoring of patients, both in hospital environments and homecare. In this paper we are exploring impulse radio as a feasible technology for health monitoring. By exploring advanced technology and novel architectures, improved quality of service may be granted. Additional interesting biomedical functionality of impulse radio is detached body sensors (short-range medical radar).

Power-Efficient Cross-Correlation Beat Detection in Electrocardiogram Analysis Using Bitstreams

In this paper, we present a novel cross-correlator chip suitable for “smart” ECG electrodes. Sophisticated QRS-detection is feasible exploring multicomponent-based cross-correlation and by exploiting the simplicity offered by bitstream processing. The chip is evaluated using real ECG signals as an example application. Power-efficient running cross correlation is obtained with novel asynchronous circuit solutions consuming approximately 730 μ W while processing ECG data sampled at a rate of 250 Hz. The implemented generic cross-correlator may be explored for other pattern-matching applications in wireless sensor networks or other low-power applications.

An inductorless 3–5 GHz band-pass filter with tunable center frequency in 90 nm CMOS

A novel inductorless tunable switched-capacitor band-pass filter based on N-path periodically time-variant networks is presented. The proposed UWB band-pass filter is complete with ring-oscillator used for multi-phase clock generation suitable for power-efficient IR-UWB systems. The filter prototype was fabricated in TSMC 90 nm CMOS, and occupies a chip area of 0.004 mm2. It archives a -3 dB bandwidth of 2 GHz while the center frequency can be tuned from 4 GHz to 4.4 GHz. Power consumption is 1.1 mW from 1.2 V supply voltage, and the performance was verified experimentally.

CMOS nanoscale impulse radar utilized in 2-dimensional ISAR imaging system

This paper presents a complete impulse based radar transceiver integrated on a single chip. The high bandwidth of the transmitted pulses offers unique penetration abilities and very high accuracy. By taking advantage of the Continuous Time Binary Valued (CTBV) design paradigm, some of the main show stoppers of systems based on traditional digital design techniques have been removed. This paper explores the advantages and possibilities of the fully integrated CTBV radar, and introduces basic background on the Inverse Synthetic Aperture Radar (ISAR) along with experimental results. Measurements have been performed that confirm the theory and show that the proposed nanoscale impulse radar system may be utilized for 2D-imaging combining low cost implementation with high quality. The CMOS radar consumes 113mW from a 1.2V/2.5V power supply.