This paper presents a very compact band-pass waveguide resonator using second resonance of complementary split ring resonators (CSRRs). Analytical equations are used to calculate the resonance frequency of the CSRR. It has been predicted and verified experimentally that second resonance of the CSRRs has lower loss and larger bandwidth rather than first one.
This paper peresents a novel Microstrip Low-Pass Filter (LPF) using a simple symmetrical U-shaped resonator. In this work, a 5.45GHz LPF is developed. The experimental results show that in comparison with other LPFs, it has a wide stopband with high attenuation in the stopband and acceptable sharp frequency response. The insertion-loss is less than 0.1dB and the rejection band over -20dB covers 6.05GHz to 37.35GHz. The measured and simulated results are in good agreement.
We propose a novel scheme for predicting the recognition performance by using confidence intervals. Biometrics is the best solution for preventing illegal sharing of authentication solutions (e.g., password, identity card) in a multi-factor authentication system. However, information acquired using sensors contains considerable noise, which can lead to errors. Our proposed scheme provides an efficient solution for treating noise and the resulting errors. When an image acquired using the sensor includes considerable noise and the estimated matching result is “fail,” the proposed scheme offers a short path. Our experimental results show the efficiency of the proposed scheme.
This paper presents an improved design of a radiation-hardened static random access memory (SRAM). The simulation results based on the 0.18µm standard digital CMOS technology show that its static current drops dramatically compared with the WHIT cell, and the write speed is equivalent to that of other cells. The memory cell is extremely tolerant to logic upset as it does not flip even for a transient pulse with 100 times the critical charge of the ROCK cell. According to these features, this novel cell suits high reliability applications, such as aerospace and military.
In long term evolution (LTE), home evolved node B (HeNB) has been introduced to improve indoor channel quality and take over indoor traffic from macro eNB (MeNB) at a low cost. As MeNB and HeNB share radio resources to obtain high capacity, victim macro user equipments (VMUEs) may exist due to severe interference from HeNB. For efficiently coordinating interference to the VMUEs, the HeNB should exactly perceive presence and absence of its neighboring VMUEs. In this paper, we propose a VMUE detection procedure based on network assistance in LTE-femtocell networks. By using the proposed detection procedure, HeNB can appropriately perform interference coordination (IC) as detection results of VMUE. Performance evaluations show the throughput of MUEs can be improved by combining the proposed procedure and IC.
A novel sensing algorithm for non-volatile Spin-Transfer Torque Magneto-resistive Random Access Memory (STT-MRAM) is presented. The dynamic reference sense amplifier (DRSA) improves sensing margin to achieve high reliability and sensitivity by increasing the difference of input voltages of sense amplifier. A dynamic reference sensing algorithm is proposed as a solution for the read margin loss due to variation in magnetic tunneling junction (MTJ) parameters of the STT-MRAM. The proposed sensing method was designed in standard 0.18um process parameters, and simulation results indicate simultaneously increased the read margin compared with the conventional sensing method.
A highly compact microstrip-fed planar monopole antenna is proposed. It consists of a radiation patch, four stubs and a truncated ground. The antenna exhibits dual-band operation with -10dB return loss bandwidths 0.45GHz (2.20-2.65GHz) and 5.23GHz (6.52-11.75GHz) in the lower band and upper band, respectively. Simulated and measured results show this antenna is suitable for WLAN, UWB and other wireless communication applications.
This letter presents a new architecture of merged low noise amplifier and mixer, which employs a noise cancellation scheme and uses an inductor as an inter-stage matching network between LNA and mixer to absorb parasitic capacitances. As the parasitic capacitances degrade the gain and noise figure of the entire circuit, using an inductor in the inter-stage can very effectively improve both noise figure and gain of the circuit. Based on this new method, a merged LNA-mixer has been designed in a 0.18-µm RF CMOS technology. Simulation results show 4-dB increase in power conversion gain and 1.7-dB improvement in noise figure in comparison with the case without inter-stage filter. This circuit draws only 5mA from a 1.8V supply and covers the frequency range of 1.3GHz to 4.1GHz. Its large bandwidth as well as low power consumption makes it suitable for rapidly growing software defined radio RF transceivers.
Reducing the routing table size to obtain better scalability of network is more and more important for data center networks in cloud computing era. In this paper, virtual hierarchical mesh networks with different agent selection methods of different subnets are proposed to solve the network scaling embarrassment problem. Theoretical analysis and simulation results show the multi-agent selection methods outperform the single one in terms of end-to-end latency and load balance.
In this paper, a numerically investigation of the aperture diameter in intracavity-contacted oxide-confined GaN-based VCSEL is presented. Simulation results show that with increasing of the current aperture diameter, there is a reduction in the differential resistance of the VCSEL. The influence of oxide aperture on the threshold current has also been investigated. There is an enhancement in the threshold current of the VCSEL by increasing the oxide aperture diameter.
Communications void in geographical routing protocols effects the performance of these routing protocols. A geographic routing protocol usually uses a greedy forwarding scheme with a recovery policy to solve the void problem. In this paper, we propose a new positive virtual position (PViP) scheme, for solving the local minimum problem. Positive virtual position of nodes are considered when selecting the next optimum neighbor node. Positive virtual position of a node is the average positions of node's itself position and all single-hop neighbor nodes that are closer to the sink than itself. Simulation results demonstrate that proposed scheme increases the success delivery rate compared with other schemes without any significant overhead.
In this express, we propose an extending method, which extends the residue set of modulus (2n-2p-1) from [0,2n-2p-1) to [0,2n-1]. The proposed extending method can simplify modulo (2n-2p-1) operations and we can simply cope with the bits weighted by 2n+k(k≥0). With the proposed extending method, we propose an universal architecture for designing high-efficient modulo (2n-2p-1) multipliers on the condition n≥2p+1. Synthesized results demonstrate that the proposed modulo (2n-2p-1) multipliers have a good performance.
This paper presents a novel silicon controlled rectifier (SCR)-based ESD protection device with a low trigger voltage and high robustness for I/O clamp. The low trigger voltage is achieved by injecting the trigger current into main SCR. We measured the I-V characteristics, leakage current analysis and ESD robustness characteristics. The proposed ESD protection circuit was validated using a transmission line pulse (TLP) system. From the experimental results, the proposed ESD protection device has a lower trigger voltage of 5.6V. Also, the robustness has measured to human body model (HBM) 8kV and machine model (MM) 600V. The proposed ESD protection device is designed in 0.35um Bipolar-CMOS-DMOS (BCD) technologies.
This paper reports the demonstration of a radio over fiber (RoF) - distributed antenna system (DAS) over a wavelength division multiplexing - passive optical network (WDM-PON) with multiple input multiple output (MIMO) by employing bandpass-sampling and optical time division multiplexing (TDM) techniques to realize next generation broadband wireless access with a gigabit-class throughput. We experimentally evaluate the performance of two optical transmissions of radio frequency (RF) signals, which are multiplexed 2.4 and 5GHz bands 802.11n RF signals in the time-domain and distributed 2.4GHz band 2×2 MIMO 802.11n RF signals with 2 channels WDM.