7.3 W of single-frequency output power at 2.09 μm from an Ho:YAG monolithic nonplanar ring laser

Single-frequency output power of 7.3 W at 2.09 mu m from a monolithic Ho:YAG nonplanar ring oscillator (NPRO) is demonstrated. Resonantly pumped by a Tm-doped fiber laser at 1.91 mu m, the Ho:YAG NPRO produces 71% of slope efficiency with respect to absorbed pump power and nearly diffraction-limited output with a beam quality parameter of M-2 approximate to 1.1. (c) 2008 Optical Society of America

An ultra-low power CMOS random number generator

This paper proposes an ultra-low power CMOS random number generator (RING), which is based on an oscillator-sampling architecture. The noisy oscillator consists of a dual-drain MOS transistor, a noise generator and a voltage control oscillator. The dual-drain MOS transistor can bring extra-noise to the drain current or the output voltage so that the jitter of the oscillator is much larger than the normal oscillator. The frequency division ratio of the high-frequency sampling oscillator and the noisy oscillator is small. The RNG has been fabricated in a 0.35 mu m CMOS process. It can produce good quality bit streams without any post-processing. The bit rate of this RNG could be as high as 100 kbps. It has a typical ultra-low power dissipation of 0.91 mu W. This novel circuit is a promising unit for low power system and communication applications. (c) 2007 Elsevier Ltd. All rights reserved.

Detailed model and investigation of gain saturation and carrier spatial hole burning for a semiconductor optical amplifier with gain clamping by a vertical laser field

A detailed model for semiconductor linear optical amplifiers (LOAs) with gain clamping by a vertical laser field is presented, which accounts the carrier and photon density distribution in the longitudinal direction as well as the facet reflectivity. The photon iterative method is used in the simulation with output amplified spontaneous emission spectrum in the wide band as iterative variables. The gain saturation behaviors and the noise figure are numerically simulated, and the variation of longitudinal carrier density with the input power is presented which is associated with the ON-OFF state of the vertical lasers. The results show that the LOA can have a gain spectrum clamped in a wide wavelength range and have almost the same value of noise figure as that of conventional semiconductor optical amplifiers (SOAs). Numerical results also show that an LOA can have a noise figure about 2 dB less than that of the SOA gain clamped by a distributed Bragg reflector laser.

Semiconductor optical amplifier optical gate with graded strained bulk-like active structure

A novel semiconductor optical amplifier (SOA) optical gate with a graded strained bulk-like active structure is proposed. A fiber-to-fiber gain of 10 dB when the coupling loss reaches 7 dB/factet and a polarization insensitivity of less than 0.9 dB for multiwavelength and different power input signals over the whole operation current are obtained. Moreover, for our SOA optical gate, a no-loss current of 50 to 70 mA and an extinction ratio of more than 50 dB are realized when the injection current is more than no-loss current, and the maximum extinction ratio reaches 71 dB, which is critical for crosstalk suppression. (C) 2003 society of Photo-Optical Instrumentation Engineers.

A novel ultra low power temperature sensor for UHF RFID tag chip

A novel ultra low power temperature sensor for UHF RFID tag chip is presented. The sensor consists of a constant pulse generator, a temperature related oscillator, a counter and a bias. Conversion of temperature to digital output is fulfilled by counting the number of the clocks of the temperature related oscillator in a constant pulse period. The sensor uses time domain comparing, where high power consumption bandgap voltage references and traditional ADCs are not needed. The sensor is realized in a standard 0.18 mu m CMOS process, and the area is only 0.2mm(2). The accuracy of the temperature sensor is +/- 1 degrees C after calibration. The power consumption of the sensor is only 0.9 mu W.

A Low Power Baseband Chain for CMMB Application

This paper presents experimental results of an analog baseband circuit for China Multimedia Mobile Broadcasting (CMMB) direct conversion receiver in 0.35um SiGe BiCMOS process. It is the first baseband of CMMB RFIC reported so far. A 8(th)-order chebyshev low pass filter (LPF) with calibration system is used in the analog baseband circuit, the filter provides 0.5 dB passband ripple and -35 dB attenuation at 6MHz with the cutoff frequency at 4MHz, the calibration of filter is reported to achieve the bandwidth accuracy of 3%. The baseband variable gain amplifier (VGA) achieves more than 40 dB gain tuning with temperature compensation. In addition, A DC offset cancellation circuit is also introduced to remove the offset from layout and self-mixing, and the remaining offset voltage and current consumption are only 6mV and 412uA respectively. Implemented in a 0.35um SiGe technology with 1.1 mm(2) die size, this tuner baseband achieves OIP3 of 25.5 dBm and dissipate 16.4 mA under 2.8-V supply.

Low Power Integrated Circuits for Wireless Neural Recording Applications

A group of prototype integrated circuits are presented for a wireless neural recording micro-system. An inductive link was built for transcutaneous wireless power transfer and data transmission. Power and data were transmitted by a pair of coils on a same carrier frequency. The integrated receiver circuitry was composed of a full-wave bridge rectifier, a voltage regulator, a date recovery circuit, a clock recovery circuit and a power detector. The amplifiers were designed with a limited bandwidth for neural signals acquisition. An integrated FM transmitter was used to transmit the extracted neural signals to external equipments. 16.5 mW power and 50 bps - 2.5 Kbps command data can be received over 1 MHz carrier within 10 mm. The total gain of 60 dB was obtained by the preamplifier and a main amplifier at 0.95Hz - 13.41 KHz with 0.215 mW power dissipation. The power consumption of the 100 MHz ASK transmitter is 0.374 mW. All the integrated circuits operated under a 3.3 V power supply except the voltage regulator.

A low power integrated CMOS transmitter for BCI system

The prototype wafer of a low power integrated CMOS Transmitter for short-range biotelemetry application has been designed and fabricated, which is prospective to be implanted in the human brain to transfer the extracted neural information to the external computer. The transmitter consists of five parts, a bandgap current regulator, a ring oscillator, a buffer, a modulator and a power transistor. High integration and low power are the most distinct criteria for such an implantable integrated circuit. The post-simulation results show that under a 3.3 V power supply the transmitter provides 100.1 MHz half-wave sinusoid current signal to drive the off-chip antenna, the output peak current range is -0.155 mA similar to 1.250 mA, and on-chip static power dissipation is low to 0.374 mW. All the performances of the transmitter satisfy the demands of wireless real-time BCI system for neural signals recording and processing.

A high-gain high-linearity wide-band low noise amplifier for terrestrial and cable receptions

This paper presents the design of a wide-band low-noise amplifier (LNA) implemented in a 0.35 mu m SiGe BiCMOS technology for cable (DVB-C) and terrestrial (DVB-T) tuner applications. The LNA utilizes current injection to achieve high linearity. Without using inductors, the LNA achieves 0.1-1GHz wide bandwidth and 18.8-dB gain with less than 1.4-dB gain variation. The noise figure(NF) of the wideband LNA is 5dB, its 1-dB compression point is -2dBm and IIP3 is 8dBm. The LNA dissipates 120mW power with a 5-V supply.

Period Continuous Tuning of an Efficient Mid-Infrared Optical Parametric Oscillator Based on a Fan-out Periodically Poled MgO-Doped Lithium Niobate

We report a period continuously tunable, efficient, mid-infrared optical parametric oscillator (OPO) based on a fan-out periodically poled MgO-doped congruent lithium niobate (PPMgLN). The OPO is pumped by a Nd:YAG laser and a maximum idler output average power of 1.65 W at 3.93 mu m is obtained with a pump average power of 10.5 W, corresponding to the conversion efficiency of about 16% from the pump to the idler. The output spectral properties of the OPO with the fan-out crystal are analyzed. The OPO is continuously tuned over 3.78-4.58 mu m (idler) when fan-out periods are changed from 27.0 to 29.4 mu m. Compared with temperature tuning, fan-out period continuous tuning has faster tuning rate and wider tuning range.

FET ACTIVE SLOTLINE NOTCH ANTENNAS FOR QUASI-OPTICAL POWER COMBINING

A new active antenna structure with applications in quasi-optical power combining is described. The active antenna combines a slotline FET oscillator with a notch antenna. The new structure was successfully used to create both E-plane and H-plane linear arrays as well as a 2-D array. Preliminary results of radiation patterns and the power combining efficiencies of the arrays are discussed.

A low power high linearity baseband for a direct conversation CMMB tuner

An analog baseband circuit made in a 0.35-μm SiGe BiCMOS process is presented for China Multimedia Mobile Broadcasting (CMMB) direct conversion receivers. A high linearity 8th-order Chebyshev low pass filter (LPF) with accurate calibration system is used. Measurement results show that the filter provides 0.5-dB pass-band ripple, 4% bandwidth accuracy, and -35-dB attenuation at 6 MHz with a cutoff frequency of 4 MHz. The current steering type variable gain amplifier (VGA) achieves more than 40-dB gain range with excellent temperature compensation.This tuner baseband achieves an OIP3 of 25.5 dBm, dissipates 16.4 mA under a 2.8-V supply and occupies 1.1 mm~2 of die size.

A Wide-Band Low Noise Amplifier for Terrestrial and Cable Receptions

We present the design of a wide-band low-noise amplifier （LNA） implemented in 0.35μm SiGe BiCMOS technology for cable and terrestrial tuner applications. The LNA utilizes current injection to achieve high linearity. Without using inductors, the LNA achieves 0.1 ～ 1GHz wide bandwidth and 18. 8dB gain with less than 1.4dB of gain variation. The noise figure of the wideband LNA is 5dB, and its 1dB compression point is - 2dBm and IIP3 is 8dBm. The LNA dissipates 120mW of power with a 5V supply.

Exploring the Origin of Power Law Distribution in Single-Molecule Conformation Dynamics: Energy Landscape Perspectives

We explored the origin of power law distribution observed in single-molecule conformational dynamics experiments. By establishing a kinetic master equation approach to study statistically the microscopic state dynamics, we show that the underlying landscape with exponentially distributed density of states leads to power law distribution of kinetics. The exponential density of states emerges when the system becomes glassy and landscape becomes rough with significant trapping.