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This paper describes on trend of the recent technology developments for wireless communications and consists of four parts. The first and most important development is the worldwide Internet traffic growth. The important trends in, the "worldwide Internet traffic" growth are summarized in terms of the global geographic areas and their Internet penetrations. The second item is the developments...
Metamaterials have the potential to allow engineers to tailor the electromagnetic responses of the materials incorporated in antenna systems to enhance their performance. Several examples of the exotic properties of electromagnetic metamaterials will be given. One class of metamaterials that has already demonstrated its usefulness with antennas is the artificial magnetic conductor (AMC). It has been...
Summary form only given. This talk traces the evolution of wireless technologies from the early personal communications systems of the 1980's to the present day voice over IP and broadband multimedia services over the ubiquitous wireless network. The speaker will compare the parallel developments of wireless and wireline broadband networks and examine the extent of their convergence. Future trends...
A full monolithic low-phase-noise wide-tuning-range voltage-control-oscillator (VCO) designed for a dual-band homodyne transceiver for WLAN applications is presented in this paper. The circuit is designed and implemented in a commercial 0.35 SiGe BiCMOS process. MOS varactor is used to realize a wide tuning range. Measured VCO circuit specifications feature a 440 MHz tuning range around 2.45 GHz,...
In this paper, the research advances on substrate integrated waveguide (SIW) technology and its application in microwave antennas, components and subsystems in the State Key Lab. of Millimeter Waves (SKLMMW) are reviewed, which includes the propagation characteristics and discontinuity analysis of SIW, and its application in the design and implementation of directional antennas, omni-directional antennas,...
Three core requirements are discussed for the implementation of distributed intelligent systems: a peer-to-peer communications infrastructure, a multi-agent architecture, and a means to provide distributed logistics for the management and self-organization of system resources. We distinguish between a distributed system and a distributed intelligent system, and the inherent advantages that they have...
This paper reviews a Fourier transform and mode-matching analysis of radiation from apertures on coaxial cables and on conducting circular cylinders. The boundary-value problems of radiation from multiple apertures on conducting circular cylinders are solved subject to the boundary conditions. Analytic, rigorous solutions to the boundary-value problems are obtained using residue calculus. Salient...
In this article, we introduce some latest research results on the dosimetry of children for mobile phones. The contents include a comparison for the SAR characteristics in anatomical head models of adult and children, and an approach to the age effect of dielectric properties on the peak SAR. An international inter-comparison of SAR calculation is also introduced
In this paper, quaternion was introduced in estimating azimuth and elevation of two dimensional direction of arrival (2-D DOA). We proposed a new quaternion signal model instead of classical complex signal model. Then, two definitions of multiplicative rules of quaternion were introduced. At last, we drew out azimuth and elevation using two definitions of quaternion and isomorphic complex expression...
A cross-entropy based parameter is proposed to measure the difference between a river area and others. This parameter can be employed for ship detection from a polarimetric SAR image. After deciding the boundaries of the river area, ships are detected only in the river area instead of the whole site. Therefore, most of the false alarms are eliminated. Finally, the performance of this new approach...
A new twin TEM cells' design is brought forward by analyzing symmetrical TEM Cells. This kind of twin TEM cells could doubly amplify the testing space. This paper analyzes electromagnetic field in the twin TEM cells using FEM method and draws a conclusion
A compound conical monopole antenna fed by coaxial line is fabricated and analyzed using the method of finite integration technique (CST). The designed antenna, which consists of one solid cone and several wires, has several merits such as broadband, light weight, omnidirectional radiation
In this paper, a novel high sensitive active integrated antenna (AIA) structure for 2.4 GHz receivers is developed. The antenna is made of a rectangle microstrip probe-fed antenna and a front-end low noise amplifier (LNA) without a matching circuit in between. They are integrated in a two-layer planar structure and operate at 2.48 GHz. The final measurement shows: comparing to the passive antenna,...
Achieving low side lobe level array antennas without implementation of phase shifters or amplitude tapering is a valuable solution in cases, which the simplicity of the structure is of high importance. In this paper a low sidelobe level microstrip array antenna is designed for GSM base-station antenna application using genetic algorithm by variation of the distances between elements around their nominal...
The performance of adaptive digital beamformer (ADBF) will be degraded when the expected signal is mixed in the sample data and the expected signal will be cancelled. If the interference locates in the mainlobe areas, the mainbeam will be distorted with conventional ADBF for the sake of suppressing the mainlobe interference. In this paper, a modified block matrix (MBM) method is proposed. This method...
An eight stage distributed amplifier with 12.5 dB plusmn 0.45 dB gain and 50 GHz bandwidth has been demonstrated in a commercially available 0.1 mum metamorphic GaAs HEMT (MHEMT) technology. The amplifier has a minimum noise figure lower than 2.5 dB in the bandwidth. The group delay variation, from 9 to 40 GHz is plusmn 7.5 ps and circuit consumption is 0.4 W. Such amplifier has been packaged with...
In this paper, a modified UTD model to predict the propagation channel parameters in indoor scenarios is presented. The model is based on the blueprint of the rooms for a transmitter and receiver located at the same room. It employs two plane views reference to the transmitter and the receiver, respectively and a new criteria adopting vector's dot product to construct the visibility graph. To verify...
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