A differential BPSK transmitter for ultra-wideband impulse-radio communication has been presented in this paper. The transmitter, developed in a 65 nm CMOS process,is simple in design and occupies a core area of 0.0017 mm2. The differential Gaussian monocycle pulses (GMP) are generated using some logic blocks and delay elements. The generated GMP, having a center frequency above 5 GHz, meets the FCC regulations. Measured results show that the transmitter consumes 1.8 pJ/bit to transmit BPSK modulated GMP at a data rate of 2 Gb/s. The interface circuitries eliminate the need for external networks for chip to antenna matching. Using an off-chip differential bow-tie antenna, data can easily be transmitted up to a distance of 10 cm which made it suitable for low power far field non-coherent applications.

The interface between laser-recrystallized Si and SiO2 is investigated by means of capacitance-voltage curve measurements. The recrystallization is performed by scanning cw Ar+ laser. The change in the C-V curves shows that the laser-recrystallization generates positive charge and the fast interface states at the Si-SiO2 interface, and creates n-type defects in recrystallized bulk silicon. Nominal interface charge increases linearly with a laser power. The increase in the charge is enhanced by fast laser-beam scanning velocity. The change in the C-V curve is suppressed, if a substrate is heated up to 450 during recrystallization. Complete recovery of the induced change in the C-V curves requires a subsequent furnace annealing at a temperature as high as 1100. These phenomena are explained by the generation of oxygen vacancy at the Si-SiO2 interface and quenched-in point defects in the recrystallized Si. The oxygen vacancy is produced by a reaction between the melted Si and SiO2. The quenched-in defects are produced during fast cooling of the melted Si.

A differential input non-coherent BPSK receiver for the UWB-IR communication, based on threshold detection, has been presented in this paper. The chip can recover BPSK modulated Gaussian monocycle pulses (GMP), along with its first derivative, at a data rate of 500 Mb/s. No clock reception is required, as the receiver recovers data based on the relative phase of the two simultaneously received inputs. While retrieving the data, it consumes a power of 63 mW from a supply voltage of 1.8 V. A shunt-peaked narrow band amplifier, matched to the input antenna, is used to amplify the received GMP. Wireless data have been successfully recovered using a pair of horn antennas at a distance of 6 cm. The chip, developed in a 180 nm CMOS technology, occupies a die area of 3.4 mm2. The receiver is suitable for the non-coherent (self-synchronized) UWB-IR communication.

This paper reviews the potential possibility and present status of trans-polyacetylene research toward realization of soliton molecular devices utilizing characteristics of the quasi-one-dimensional conductor. Properties of solitons in polyacetylene are summarized from a point of view to produce a new microelectronics beyond Si-LSI's. The limiting performance of soliton LSI's are roughly estimated. One bit information is stored in only 420 2. The information transmission rate of a wiring is 2104 Gb/s. The delay time per gate is 0.05 ps. For realization of this high performance devices, a lot of research must be carried out in future. A new circuit with new principles of operations must be developed to achieve the performance, where a localized soliton or a localized group of solitons are treated. Some systems, which may lead to development of logic circuits, are proposed. The problems in crystal quality and fabrication process are also discussed and some means against them are presented.

A CMOS detection procedure for ultra-wideband impulse radio (UWB-IR) communication system, employing Bi-Phase Shift Keying (BPSK) modulation scheme, is presented here. The chip was designed and fabricated in a 180 nm CMOS process and it requires a supply voltage of 1.8 V, with a die area of 0.01 mm2. A train of Gaussian Monocycle Pulses (GMP), modulated by a random data sequence of 1 Gb/s, has been detected successfully by the detector. Ability to process differential data without using conventional blocks like mixer, correlator etc. while consuming a very low power (3.8 pJ/bit for a data rate of 1 Gb/s) is the novelty of this work. The detection scheme employing a simple architecture with a noncoherent detection mechanism is well suited for UWB-IR communication system.