The Gilbert-Holland FDTD thin slot model revisited: an alternative expression for the in-cell capacitance

This paper proposes an alternative expression for the in-cell capacitance of a photoelectrical cell (PEC)-mounted slot, which is the conceptual cornerstone of the Gilbert-Holland subcell finite difference time domain (FDTD) model. By treating a slightly modified electrostatic problem, the extraneous charge singularity on the PEC edges touching the cell, which is characteristic of the originally proposed model, is removed. The latter offers better physical grounds for a new expression of the capacitance and the effective permittivity used in the update equations. High resolution standard FDTD simulation results are presented in support of the new expression.     

A fast algorithm and practical considerations for passive macromodeling of measured/simulated data

Passive macromodeling of high-speed package and interconnect modules characterized by measured/simulated data has generated immense interest during the recent years. This paper presents an efficient algorithm for transient simulation of interconnect networks characterized by measured/simulated data in the presence of other linear and nonlinear devices. A new set of linear constraints are proposed, which help in preserving the passivity of resulting macromodels. Examples are presented to demonstrate the validity and efficiency of the proposed algorithm.     

A biomorphic digital image sensor

An arbitrated address-event imager has been designed and fabricated in a 0.6-/spl mu/m CMOS process. The imager is composed of 80 /spl times/ 60 pixels of 32 /spl times/ 30 /spl mu/m. The value of the light intensity collected by each photosensitive element is inversely proportional to the pixel's interspike time interval. The readout of each spike is initiated by the individual pixel; therefore, the available output bandwidth is allocated according to pixel output demand. This encoding of light intensities favors brighter pixels, equalizes the number of integrated photons across light intensity, and minimizes power consumption. Tests conducted on the imager showed a large output dynamic range of 180 dB (under bright local illumination) for an individual pixel. The array, on the other hand, produced a dynamic range of 120 dB (under uniform bright illumination and when no lower bound was placed on the update rate per pixel). The dynamic range is 48.9 dB value at 30-pixel updates/s. Power consumption is 3.4 mW in uniform indoor light and a mean event rate of 200 kHz, which updates each pixel 41.6 times per second. The imager is capable of updating each pixel 8.3K times per second (under bright local illumination).     

Bias-temperature instabilities of polysilicon gate HfO/sub 2/ MOSFETs

Bias-temperature instabilities (BTI) of HfO/sub 2/ metal oxide semiconductor field effect transistors (MOSFETs) have been systematically studied for the first time. NMOS positive BTI (PBTI) exhibited a more significant V/sub t/ instability than that of PMOS negative BTI (NBTI), and limited the lifetime of HfO/sub 2/ MOSFETs. Although high-temperature forming gas annealing (HT-FGA) improved the interface quality by passivating the interfacial states with hydrogen, BTI behaviors were not strongly affected by the technique. Charge pumping measurements were extensively used to investigate the nature of the BTI degradation, and it was found that V/sub t/ degradation of NMOS PBTI was primarily caused by charge trapping in bulk HfO/sub 2/ rather than interfacial degradation. Deuterium (D/sub 2/) annealing was found to be an excellent technique to improve BTI immunity as well as to enhance the mobility of HfO/sub 2/ MOSFETs.     

Research issues in genomic signal processing

Genomic signal processing (GSP) concerns the processing of genomic signals. It may be defined as the analysis, processing, and use of genomic signals to gain biological knowledge and the translation of that knowledge into systems-based applications. In this article, the authors discuss the key research issues for GSP. It is important to recognize that "genomic signal processing" is not a name for genomic bioinformatics nor for the application of signal processing methods in genomics. We note that the research issues pertaining to GSP fit within the overall challenges confronting research in the area of multimodal biomedical systems.     

Monolithic integration of a 5.3 GHz regenerative frequency divider using a standard bipolar technology

A monolithic microwave frequency divider IC with an operating range of 1.4?5.3 GHz was developed and fabricated in a standard bipolar technology. The circuit operates on the principle of `regenerative frequency division?. Compared to the most popular divider concepts based on a master-slave D-flip-flop, an almost twice as high input frequency can be divided, provided that the same technology is used. A further advantage is the low power consumption.     

A 72-mW CMOS 802.11a direct conversion front-end with 3.5-dB NF and 200-kHz 1/f noise corner

A direct conversion 802.11a receiver front-end including a synthesizer with quadrature VCO has been integrated in a 0.13-/spl mu/m CMOS process. The chip has an active area of 1.8 mm/sup 2/ with the entire RF portion operated from 1.2 V and the low frequency portion operated from 2.5 V. Its key features are a current driven passive mixer with a low impedance load that achieves a low 1/f noise corner and an high I-Q accuracy quadrature VCO. Measured noise figure is 3.5 dB with an 1/f noise corner of 200 kHz, and an IIP3 of -2 dBm. The synthesizer DSB phase noise integrated over a 10 MHz band is less than -36 dBc while its I-Q phase unbalance is below 1 degree.