Simulation Results. (simulation + results)

Distribution by Scientific Domains


Selected Abstracts


Compact UWB microstrip lowpass filter with novel CMRC

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 5 2007
Fei Zhang
Abstract A novel beeline compact microstrip resonant cell, entitled BCMRC (beeline compact microstrip resonant cell), is firstly proposed and analyzed. The photonic bandgap and slow-wave effect of the BCMRC are evaluated. The compact configuration presents ultrawide stopband and improved slow-wave characteristics. Investigation of its scattering/radiation level is also included. An ultrawide band lowpass filter, consisting of three BCMRCs connected in series, is designed and fabricated. The filter has the advantages of low insertion loss in the passband, sharp, high and wide rejection in the stopband and compact size. The experimental results show good agreements with simulation results. 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007. [source]


Project AURORA: Infrastructure and flight control experiments for a robotic airship

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 3-4 2006
Ely Carneiro de Paiva
Project AURORA aims at the development of unmanned robotic airships capable of autonomous flight over user-defined locations for aerial inspection and environmental monitoring missions. In this article, the authors report a successful control and navigation scheme for a robotic airship flight path following. First, the AURORA airship, software environment, onboard system, and ground station infrastructures are described. Then, two main approaches for the automatic control and navigation system of the airship are presented. The first one shows the design of dedicated controllers based on the linearized dynamics of the vehicle. Following this methodology, experimental results for the airship flight path following through a set of predefined points in latitude/longitude, along with automatic altitude control are presented. A second approach considers the design of a single global nonlinear control scheme, covering all of the aerodynamic operational range in a sole formulation. Nonlinear control solutions under investigation for the AURORA airship are briefly described, along with some preliminary simulation results. 2006 Wiley Periodicals, Inc. [source]


Position/Force Control of an Underwater Mobile Manipulator

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 12 2003
Lionel Lapierre
This paper proposes a new control method applied to an underwater vehicle equipped with a robot manipulator. This control method is based on force control to stabilize the platform when the manipulator works in free or constrained space. The torque produced by the arm on the platform is estimated with a force sensor installed between the base of the manipulator and the vehicle. This allows correcting the position errors of the platform using an external force control loop. This paper presents this control law and shows some simulation results. 2003 Wiley Periodicals, Inc. [source]


Building and navigating a network of local minima

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 8 2001
Seung-Woo Kim
We present a novel method that constructs and navigates a network of local minima of potential fields defined over multidimensional spaces. Though motivated by problems of motion planning for robotic manipulators, similar techniques have been proposed for use in other domains such as molecular chemistry and drug design. The method is based on building a roadmap of paths connecting local minima of a potential function. The novel approach consists of an up-hill search strategy used to climb out of local minima and find new nearby local minima, without doubling back on previous local minima. With this up-hill search strategy, one can find local minima otherwise difficult to encounter, and one can focus the search to specific local minima and specific directions from those local minima. The construction of the roadmap can be done in parallel with very little communication. We present extensive simulation results. 2001 John Wiley & Sons, Inc. [source]


Miniaturized band-stop filter based on multilayer-technique and new coupled octagonal defected ground structure with interdigital capacitor

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2010
A. Boutejdar
Abstract In this article, we proposed a new compact defected ground structure (DGS) band-stop filter with broad passband and low insertion loss in the stop-band. The philosophy of the structure behind this new microstrip band-stop filter is simple as it is composed of a pair of octagonal DGS-slots and an open-stub as compensated microstrip capacitance. The filter will be realized through direct electromagnetic coupling and slow wave effect methods. With this configuration, the BSF with higher compactness, broad passband and sharp transition characteristics was realized. The design formulas are derived by using an equivalent-circuit model of a parallel L - C resonator. Finally, an interdigital-capacitor has been designed and included in the DGS-ring-element. Better compactness of the structure and symmetry of the frequency response have been achieved as well as two reflection zeros closed to the stopband have been obtained. Thus, a selectivity of the proposed filter has been improved. To validate the feasibility of the proposed design method, both band-stop filters are designed, fabricated, and measured. The experimental results agree well with the simulation results. 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 510,514, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24967 [source]


Design of compact coplanar bandstop filter composed on open-loop-ring resonator and defected ground structure (DGS)

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2010
Anatoliy Batmanov
Abstract Design of a novel compact bandstop filter composed on an open-loop-ring resonator and a defected ground structure (DGS) for coplanar waveguide is proposed and investigated. A simple coplanar open-loop-ring resonator has been designed and tested for the stop-band from 3.9 to 4.3 GHz with tree transmission zeroes inside the stop-band. Two almost symmetrical poles are obtained on both sides of the stop-band. Then the proposed broad band bandstop filter based on the one open-loop-ring resonator has been transformed to the bandstop filter with a narrower stop-band but with improved pass- and stop-band characteristics. It is realized by adding a conventional rectangular DGS slot inside the open-loop-ring. The equivalent circuit model has been proposed to describe the behaviour of the bandstop filters. The improved bandstop filter introduces the stop-band from 3.75 to 5.3 GHz with two transmission zeroes within and more than ,20 dB rejection. The total size of the proposed structure is 13.8 13.4 mm2. Both bandstop filters have been fabricated and measured. Measurements are in good agreement with simulation results. 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 478,483, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24905 [source]


Design of microstrip bandpass and lowpass filters using coupling matrix method and a new hairpin defected ground structure

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2008
Ahmed Boutejdar
Abstract In this work, we present a novel compact hairpin defected ground structure (DGS) bandpass and lowpass microstrip filter using two hairpin-slots etched in the ground plane. A compact microstrip BPF using coupled DGS resonators is designed using coupling matrix method. The designed BPF showed very wide stopband with two transmission zeros. Furthermore, a simple technique to transform the designed BPF to a LPF was presented. The BPF was fabricated and measured. The measurement results showed good agreement with the theoretical and simulation results. 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2898,2901, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23794 [source]


Microstrip stepped-impedance hairpin resonator low-pass filter with defected ground structure

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2006
Ju-Hyun Cho
Abstract In this paper, a new microstrip stepped-impedance hairpin resonator (SIR) low-pass filter (LPF) using a defected ground structure (DGS) is proposed. The proposed SIR hairpin low-pass filter using DGS provides a very sharp cutoff frequency response with low insertion loss. Furthermore, the SIR hairpin low-pass filter can provide attenuation poles for the wide-stopband characteristic due to the resonance characteristic of the DGS. Design parameters for the SIR low-pass filter are derived based on stepped-impedance theory and the equivalent-circuit model for the DGS. The experimental results show excellent agreement with the theoretical simulation results. 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 405,408, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21364 [source]


Evolution of the reverse link of CDMA-based systems to support high-speed data

BELL LABS TECHNICAL JOURNAL, Issue 3 2002
Nandu Gopalakrishnan
Development of an upcoming release of the CDMA2000* family of standards is expected to focus on enhancing the reverse link (RL) operation to support high-speed packet data applications. The challenge is to design a system that yields substantial throughput gain while causing only minimal perturbations to the existing standard. We are proposing a system that evolves features already present in the CDMA2000 Release B and IS-856 (1xEV-DO) standards and reuses concepts and capabilities that have been introduced for high-speed packet data support on the forward link (FL) in Release C of the CDMA2000 standard. The RL of Release C of the CDMA2000 standard supports a relatively slow scheduled operation of this link using signaling messages. Scheduling with shorter latencies can be achieved by moving this functionality to the physical layer. Concurrently, both the FL and RL channel conditions may be tracked, and users may be scheduled based on this knowledge. To further manage the power and bandwidth cost on the FL, that is, of scheduling users' transmissions on the RL, the mobile station (MS) is permitted to operate in either a scheduled mode or an autonomous mode. A capability is provided for the MS station to switch the mode of operation. Performance impact of, and gain from, some of the system features is characterized through simulation results. 2003 Lucent Technologies Inc. [source]