We report the measurement results and compensation of the antenna elevation angle dependences of the Submillimeter Array (SMA) antenna characteristics. Without optimizing the subreflector (focus) positions as a function of the antenna elevation angle, antenna beam patterns show lopsided sidelobes, and antenna efficiencies show degradations. The sidelobe level increases and the antenna efficienc...

This paper proposes and verifies a SAR measurement procedure for a multi-antenna transmitter that requires the measurement of two-dimensional electric field distributions for the number of antennas and the calculation for obtaining the three-dimensional SAR distributions for arbitrary weighting coefficients of the antennas prior to determining the average SAR. The proposed procedure is verified...

Wennström, M., 2002. On MIMO Systems and Adaptive Arrays for Wireless Communications: Analysis and Practical Aspects, 291 pp. Uppsala. ISBN 91-5061619-6. This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and ...

This article proposes an approach to increase the efficiency of the U-shaped cross section antenna. The Optimization of a wideband U-shaped cross section antenna on a U-shaped ground plane is presented suitable for WLAN in various applications. The proposed antenna has been developed from a single element of U-shaped cross-sectional antenna. A single element is easy to be composed for installin...

antenna are shown in Fig. 2. By carefully designing the matching network, very good impedance performance is obtained. The 2 1 VSWR is obtained from 3.9 to 6.YGHz. The bandwidth is 3GHz, or 55.6%. The measured axial ratio and gain of the proposed antenna are shown in Fig. 3. The results show that from 4.8 to 6.0GHz. less than 3dB axial ratio at boresieht for the forward direction (from the grou...

A common theme in modern wireless communications is the use of multi-antenna techniques , such as beamforming and spatial multiplexing in order to improve the cell capacity and throughput. A common problem encountered by customers today, is the inability to verify and visualize the signal at the RF antenna. This white paper will summarize multi-antenna techniques, before introducing the concept...

A high performance monopole antenna fabricated using a folded wire line and metal patch as radiator is presented. A prototype of the proposed monopole antenna with a compact area size is implemented, and the multi-band WLAN antenna shows a wide operating bandwidth of about 530MHz and 3400MHz for low band and high band, bandwidth, making it easy to cover the IEEE 802.11a, IEEE 802.11b, IEEE 802....

A low-cost, fully operational cylindrical and spherical near-field antenna measurement system designed, built, and programmed by a University of Rhode Island Capstone team is presented. The goal of this project was to modify an existing planar near-field system and apply new processing techniques to extract the far-field patterns of an antenna under test (AUT) of any physical shape. The aim of ...

this paper presents an e-ring shaped printed monopole antenna for uwb applications with dual notched bands performance. in order to generate single frequency band notch function, we applied a u-ring shaped monopole antenna, and by inserting a rectangular ring in the centre of it an e-ring shaped radiating patch created and a dual band-notch function can be achieved. the measured bandwidth of th...

INTRODUCTION A multi-antenna transmitter, e.g. in Multi-Input Multi-Output (MIMO) systems, will be implemented in the user equipment (UE) of mobile communication systems in the near future [1]. Applying the standardized procedures [2][3] for obtaining the maximum average Specific Absorption Rate (SAR), which is an evaluation index for RF exposure to human, requires the measurement of the three-...