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Recently, along with the booming of research and production of a CMOS integrated biosensing system (IBS), the ultralow current-mode amplifier (ULCA), which serves for the preamplification of biosensor signals, has been in high demand in areas like ultralow biocurrent analysis and detection, deoxyribonucleic acid probing and surveying systems, etc. in this brief, a novel ULCA is presented and implemented in SMIC 0.18-[micro]m CMOS technology by elaborately considering gain, bandwidth, noise, and offset issues. The experimental results show that the proposed ULCA can completely satisfy the specifications of IBS and stably provide the current gain of 19.9 dB, 3-dB bandwidth of 15 kHz, and input range of -0.4 to 0.4 mA, with only 1.5 nA of dc quiescent current. The input-referred offset and the noise current are 96.6 pA and 37.6 pArms, respectively. Index Terms--Bandwidth, integrated biosensing system (IBS), mismatch, noise, offset, subthreshold, ultralow current-mode amplifier (ULCA).

This brief presents a new passive element called Pi coil for bandwidth extension. Its transfer function and detailed design tables are given. Based on ideal elements, the proposed Pi coil can achieve the largest bandwidth extension ratio compared to its counterpart, i.e., T coil, and other similar bandwidth-enhancing techniques. In addition, the input return loss (S11) is much improved by using this technique. On-chip implementation methods of the T coil and the Pi coil are also investigated in this brief. Index Terms--Bandwidth extension, inductor, Pi coil, T coil.

This brief presents an adaptive-bandwidth (BW) phase-locked loop (PLL) that retains the optimal jitter performance over a wide frequency range via continuous background frequency calibration. The effective center frequency of the voltage-controlled oscillator (VCO) is calibrated by adjusting the feedforward division factor while a dual-PLL architecture hides the switching transients. As a result, the core ring oscillator only needs to operate over a narrow frequency range of 2 : 1 that is optimal for the jitter, supply sensitivity, and charge pump current mismatch over process, voltage, and temperature (PVT) conditions. The prototype PLL was fabricated in a 0.13-[micro]m CMOS process, consumed 36 mW of power, and occupied 1.1 x 0.46 [mm.sup.2] of area. The measured root-mean-square (RMS) tracking jitter was less than 0.2% of the reference clock period for the wide range of output frequency (2 MHz-1 GHz) and multiplication factor ([2.sup.0-9]), which supports that the PLL BW scales adaptively with the reference frequency. Compared to a PLL without frequency calibration, the proposed PLL demonstrated the jitter reduction up to 80%. Index Terms--Adaptive bandwidth (BW), automatic frequency calibration (AFC), CMOS, phase-locked loop (PLL).

Source extraction was traditionally done by sensor arrays. Recently, sensor networks have been considered as promising candidates for extraction of multiple sources. In a sensor network, each sensor observes an instantaneous linear mixture of the sources and their observations are corrupted by additive white Gaussian noise. Two sensor network models are adopted. The first one is. cluster based, in which a sensor acts as cluster head and performs local extraction of the sources based on its own observation and the received quantized data from the cluster members. Then, the extracted signal is quantized and the quantized data are sent to the sink while the sink performs global extraction of the sources. The other one is cluster free, in which data collected by the sensors are quantized and sent to the sink directly. Then, the sink performs global extraction of the sources. The proposed schemes are evaluated against the benchmarking case where the sensor observations are undistorted. Index Terms--Blind source extraction, distributed estimation, wireless sensor network.

The triple resonance network has emerged as a promising candidate for interstage bandwidth enhancement in cascaded CMOS amplifiers. This paper presents several design procedures for such networks, subject to the condition of moderate (1 dB) or no peaking in the passband, for the case where the devices can be chosen or designed, as well as the case in which the devices are given. Index Terms--Bandwidth enhancement, interstage networks, network theory, triple resonance, wide-band amplifier.

Time interleaving is one of the most efficient techniques employed in the design of high-speed sampled-data systems. However, the mismatches appearing among different channels will create distortion tones that will degrade the system performance. This paper presents a detailed analysis of the effect of sampling bandwidth mismatches in the statistical behavior of time-interleaved sampling systems. Closed-form and handy signal-to-noise distortion ratio formulas will also be derived which allow quick evaluation of the system performance, and the MATLAB simulations are provided in order to verify the effectiveness of those formulas. Finally, the corresponding design procedure extracted from the formulas will be further addressed through a design example. Index Terms--Bandwidth mismatches, sampled-data systems, time-interleaved (TI) analog-to-digital converter (ADC).

This brief presents a new quadrature phase-shift keying (QPSK) modulator for Bluetooth applications with an optimal transaction bandwidth control. The modulator reduces the bandwidth of the modulated carrier by minimizing their transition sharpness. CMOS active transformers are developed and utilized in quadrature oscillator and multiplexer of the modulator to provide comparable phase noise performance without using spiral inductors and transformers. The performance of the modulator is assessed using a 1.6-GHz QPSK base-band modulator implemented in TSMC 0.18-[micro]m 1.8-V CMOS technology and analyzed using SpectreRF from Cadence Design Systems with BSIM3v3 device models. The total transistor area and power consumption of the modulator are 2840 [micro][m.sup.2] and 30 mW, respectively. The phase noise of the quadrature oscillator is--110 dBc/Hz at 500-kHz frequency offset.

Byline: Chin Guok, Jason R. Lee, Karlo Berket Scientific computations and collaborations increasingly rely on the network to provide high-speed data transfer, dissemination of results, access to instruments, support for computational steering, etc. The Energy Sciences Network is establishing a science data network to provide user driven bandwidth allocation. In a shared network environment, some reservations may not be granted due to the lack of available bandwidth on any single path. In many cases, the available bandwidth across multiple paths would be sufficient to grant the reservation. In this paper we investigate how to utilise the available bandwidth across multiple paths in the case of bulk data transfer.