In this express, we have proposed an improved architecture for designing efficient modulo (2n-2p+1) multipliers on the condition n≥2p. The proposed modulo (2n-2p+1) multipliers can improve the current state of the art by 7.7-42.5% in terms of area and 13.1-44.2% in terms of performance delay on the average or by 60.5% in terms of area with the equivalent delay performance.
When applications exhibit more complex control flow behaviors, wide single-instruction multiple-data (SIMD) architecture is inefficient, which mainly due to two aspects, vector condition branch and nested loop. To solve this problem, this paper proposes two independent ideas: the data-aware thread-level parallelism (DATLP) and hardware-supported software pipeline scheduling policy (HSSP). They share the same hardware which is the instruction buffer queue (IBQ), to improve the efficiency by increasing Instruction-Level Parallelism (ILP) and Thread-Level Parallelism (TLP). Compared with the traditional SIMD-architecture, the proposed control-enhanced power SIMD, will get an average performance improvement by 84% for a wide variety of media and 4G wireless communication applications, while the area overhead only increases by 2.97%.
An extended-resonant output matching circuit was proposed to enhance the negative conductance, output power and phase noise of a 24GHz transformer coupled voltage controlled oscillator (VCO). The circuit was realized by a capacitive stub-loaded resonator in a voltage boosted scheme to steepen the phase slope of the oscillator. The designed VCO achieved a peak output power of +1.5dBm at 23.82GHz and a phase noise of -117dBc/Hz at 1MHz offset frequency. Meanwhile, the VCO exhibits the excellent monotonic and constant frequency tuning characteristics with nearly flat output power.
This paper deals with the implementation of an output current estimator for a DC-DC Multiplier Boost Converter (MBC). For that purpose, a real time platform is used for solving the dynamic equations of a nonlinear adaptive observer. Excellent performance is achieved even during demanding conditions. In particular, a reliable estimation is obtained when an experimental nonlinear dynamic system is utilized as an electric load connected at the converter terminals.
A compact band selection filter (BSF) is implemented in a 0.18-µm CMOS technology. The structure consists of a pair of symmetric slow wave anti-coupled line and a shunted transistor. When the transistor is in the off-state, the BSF can work as a low-pass filter. The measured insertion loss is 3dB, and the return loss is better than 9dB from DC to 10GHz. When the transistor is in the on-state, the BSF can work as a bandpass filter. The measured insertion loss is 3dB, and the return loss is better than 10dB from 14 to 27GHz.
The development of superconducting wires is one of the key issues in realizing superconducting equipment. Superconducting wires made of alloys such as NbTi have already been commercialized and applied to MRI and NMR, and superconducting wires made of metal compounds such as Nb3Sn have been manufactured for use in high-field applications such as accelerators and nuclear fusion. Since a high-TC superconductor (over 77K) was discovered approximately 25 years ago, it has been expected that they will be used in electric power apparatus such as cables and electricity storage devices. Among the various high-TC superconductors, Bi2Sr2Ca2Cu3O10 (Bi2223) and REBa2Cu3Oy (RE123) (RE: rare earth elements) have mainly been investigated with aim of producing superconducting wires. Among the other superconductors, MgB2 superconductors, which are expected to lead to a lower manufacturing cost, and the recently discovered iron-based superconductors are being studied at present. This article is focused on the development of superconducting wires for superconducting electric power apparatus reviewing the recent progress in RE123 and Bi2223 superconducting wires and their applications.
Superconductivity and optoelectronics have developed almost independently and had very rare interactions with each other in science and technologies. However recent interdisciplinary research opens up the potential for developing new optoelectronic devices. This review paper presents our recent theoretical and experimental demonstrations that superconductivity significantly modifies and accelerates photon generation processes. We have prepared superconducting light emitting diodes (LEDs) emitting at ∼1.6-µm optical-fiber communication band for the experimental demonstrations. This new-type LED operation is based on a unique physics related to Cooper-pair interband transition in a semiconductor, and further research leads to the solid-state simultaneously generated photon-pair sources for the potential application in quantum information and communication.
Minimum bit error rate (MBER) criterion is formulated to minimize the bit-error-rate (BER) of a communication system, which is the true performance indicator in channel equalization. However, MBER decision feedback equalizer (DFE) undergoes slow convergence speed, and BER misadjustment in long multipath channel as demonstrated in this paper. We propose a MBER-DFE receiver adopted with recursive least square (RLS) adaptive algorithm. Results showed that the proposed receiver can achieve faster convergence rate and considerable performance as compared to conventional MBER receiver in a realistic long ultra-wideband (UWB) multipath channel.
This letter describes a novel bootstrapped CMOS driver for driving a large RC load in ultra-low voltage VLSI. The proposed driver eliminates the leakage from boosted nodes during bootstrapping operations, resulting in lower power consumption and higher switching speed. Since the proposed driver requires no additional transistors for eliminating the leakage, further improvements on switching speed and power consumption as well as layout area are achieved. Comparison results in a 0.13µm CMOS technology indicated that the proposed bootstrapped CMOS driver achieved 82%∼18% improvements in terms of power consumption as compared to conventional bootstrapped CMOS drivers. They also indicated that the proposed driver achieved 42%∼11% improvements in terms of switching speed. Improvement on power-delay product (PDP) is as much as 160%∼30% as compared to conventional bootstrapped drivers.
In a deep submicron CMOS process, variability puts a strict requirement on noise margin in MOS current-mode logic (MCML) gates. A usual approach to achieve noise margin is to increase DC gain by sizing up differential pairs. However this results in slow output settling, which limits the maximum operating speed. Thus we propose a novel MCML latch to mitigate this trade-off by using alternating low and high gain buffer structure on a bandwidth limited node. The proposed MCML latch is designed to operate at 20GHz clock in a 32nm CMOS process and is compared with a conventional MCML latch to prove its superiority in terms of speed, power and reliability especially when bandwidth is limited.
In this paper, a passive localization of an emitter using bearing measurements named Brown algorithm is considered. We derived simple and intuitive expressions of the covariance matrix of the estimate and the CEP (Circular Error Probable) when the distances between the emitter and the moving sensor locations are constant. By using the derived explicit expressions, we propose how to get an insight on the dependence of the CEP on the various parameters such as measurement interval and a speed of sensor. From the derived expression, it is quite easy to see how the CEP changes with respect to some parameters. Intuitively, we can see that the CEP value can become very large when the parameters such as a sampling interval and a speed of the moving sensor are around some specific values. We derive closed-form expressions of the parameter values for the smallest CEP and the very large CEP.
Micro-electromechanical resonators substantially exhibit bistable and hysteretic response when nonlinear characteristics appear. Badzey et al. reported that the nonlinear micro-electromechanical resonators can be used as a mechanical 1bit memory. Based on their results, the authors propose reading and writing operations of the memory device. The reading and writing operations imply a displacement measurement and a switching of two stable periodic vibrations, respectively. In this paper, we realize a displacement measurement along an approach avoiding supplemented sensors. In addition, we achieve the switching operation between two coexisting periodic states by a displacement feedback control.