Takayasu Norimatsu

A UWB-IR Transmitter With Digitally Controlled Pulse Generator

A novel transmitter for ultra-wideband (UWB) impulse radio has been developed. The proposed architecture enables low-power operation, simple design, and accurate pulse-shape generation. The phase and amplitude of the pulse are controlled separately and digitally to generate a desired pulse shape. This digital control method also contributes to the low-power transmission and eliminates the need for a filter. The transmitter is fabricated using a 0.18-mum CMOS process. The core chip size is only 0.40 mm2. From experimental measurements, it was found that the generated signal satisfied the FCC spectrum mask, and the average power dissipation was only 29.7 mW at A 2.2-V supply voltage. Therefore, the developed UWB transmitter generates accurate pulses with low power consumption and simple design architecture

A novel UWB impulse-radio transmitter with all-digitally-controlled pulse generator

A novel transmitter for ultra-wideband (UWB) impulse radio was developed. The proposed architecture realizes low power, low complexity, and generation of a highly accurate pulse. The phase and amplitude of a pulse are controlled separately and digitally to generate a highly accurate pulse. This control method also contributes to the transmitters low power and eliminates the need for a filter. The transmitter was fabricated by a 0.18-/spl mu/m bulk CMOS process. The core chip size is only 0.40 mm/sup 2/. Measurement of this transmitter found that the FCC spectrum mask is satisfied and average power dissipation is 29.7 mW under a supply voltage of 2.2 V. These results show that the developed UWB transmitter can generate an accurate pulse with low power and low complexity.

Accurate Wireless Location/Communication System With 22-cm Error Using UWB-IR

We propose a high-accuracy, low-cost UWB-IR wireless location system based on the quasi TDOA method. The system consists of anchor nodes, a synch node and a location server. The anchor nodes synchronize each other as regulated by the synch node so that synchronization is always precise in the location process. To make the anchor node simple, the location system uses acquisition and tracking functions that can measure the time when a signal is received as accurately as pulse signal width. In addition, we performed a wireless location experiment indoors and the average error of the location measurement was 22-cm

1-cc Computer: Cross-Layer Integration With UWB-IR Communication and Locationing

The first one-cc or one-cubic-centimeter computer (OCCC) that integrates a sensor, ultra-wideband impulse radio (UWB-IR) transmitter, computing engine, and battery is demonstrated. Cross-layer integration includes SPIKE control, which achieves a record low power communication of 3.4-nW/bps with reduced operating time. Miniaturization techniques, such as wafer-level chip-size packaging and flip-chip packaging, were used to shrink the module to a volume of 1 cc. The fabricated OCCC is shown to operate as designed, communicating at distances of 10 and 30 m and at transmission rates of 10.7 Mbps and 258 kbps, respectively. The life of a 150-mAh battery in an OCCC that operates once every five minutes is estimated to be longer than 10 years. The communication-location integration (CLI) technique, which achieves 22-cm location accuracy with only a 1.3% chip area overhead, is also proposed.

A CMOS UWB-IR Receiver Analog Front End with Intermittent Operation

A low power receiver analog front end (AFE) for ultra-wideband impulse radio (UWB-IR) was developed in 0.18 mum CMOS. All circuits of the receiver AFE operate intermittently with a sampling clock of an analog-digital converter (ADC). The sampling rate of the ADC is equal to pulse repetition frequency of the received signals. Power consumption of the receiver AFE is decreased 60% by intermittent operation without degrading of receiver sensitivity. As a result, the power consumption of the receiver AFE is 38 mW at 258 kbps data rate.

Intermittent Operation Control Scheme for Reducing Power Consumption of UWB-IR Receiver

A low power ultra-wideband impulse radio (UWB-IR) receiver was developed in 0.18-mum CMOS. All circuits of the receiver AFE operate intermittently with a sampling clock of an analog-digital converter (ADC). The sampling rate of the ADC is equal to the pulse repetition frequency of the received signals. Power consumption of the receiver AFE is reduced by 60% using a developed intermittent operation scheme without degrading of receiver sensitivity. As a result, the power consumption of the receiver AFE is 38 mW. The receiver has a data rate of 258 kb/s over a distance of 52 m and of 10.7 Mb/s over a distance of 14 m.

0.7-GHz-Bandwidth DS-UWB-IR System for Low-Power Wireless Communications

A direct-sequence ultra-wideband impulse radio (DSUWB-IR) system is developed for low-power wireless applications such as wireless sensor networks. This system adopts impulse radio characterized by a low duty cycle, and a direct-sequence 0.7-GHz bandwidth, which enables low-power operation and extremely precise positioning. Simulation results reveal that the system achieves a 250-kbps data rate for 30-mdistance wireless communications using realistic specifications. We also conduct an experiment that confirms the feasibility of our system.

1-cc Computer: Cross-Layer Integration with 3.4-nW/bps Link and 22-cm Locationing

The first 1-cc computer (OCCC) which integrates a sensor, a wireless transceiver, a computing engine and a battery is demonstrated. Cross-layer innovation includes SPIKE control, which achieves record-low 3.4-nW/bps power with 3-ms UWB current control (one order lower than those of reported). Another proposal is communication-location integration (CLI), which achieves 22-cm location accuracy with 1.3% area overhead. Fabricated OCCC is verified to operate as designed.

3.3 A 25Gb/s multistandard serial link transceiver for 50dB-loss copper cable in 28nm CMOS

The amount of data traffic is increasing year by year as the number of data-rich services like cloud services and streaming services are increasing. The number of switch modules between servers should decrease to lower latency, and several servers in each rack should be connected to one switch module with cables in a data centre. Using copper cables to connect racks is attractive in terms of cost minimization. Thin cables, for example 34 AWG copper cables, make maintenance easy. The cable length should be 5-7m to connect between racks, and 34 AWG 7m cable has 48dB loss, including board trace loss, package loss and so on. So far transceivers over 25Gb/s, equalizing 35-40dB channel loss have been proposed [1-4], with which low-loss cables like 26 AWG have been required. We target a 25Gb/s transceiver equalizing over 50dB channel loss, and adopt a sub-mV dynamic DC offset cancelation and a decision-feedback equalizer (DFE) with a bias-controlled tap slicer. Both improve on the minimum input sensitivity and enable data transmission through a channel with over 50dB loss.

UHF RFID mobile reader for passive- and active-tag communication

A prototype UHF RFID reader chip for mobile-phone applications was developed. The reader architecture is designed for passive tags in compliance with the ISO/IEC 18000-6 Type C and the EPCglobal Class-1 Generation-2 protocols for UHF RFID air interface. The reader also supports communication with active tags. Experimentally measured performance shows the reader chip achieves very high sensitivities (namely, −86 dBm and −92 dBm) for passive and active RFID systems, respectively. The reader chip, with 1.8-V power supply, was fabricated in a 0.18-µm CMOS process.