Reflective array antenna

About: Reflective array antenna is a research topic. Over the lifetime, 4366 publications have been published within this topic receiving 57884 citations.

Small ultra wideband antennas for medical imaging

Abstract: Small antennas have been widely investigated and reported in various medical applications for some times. It is interesting to note that small ultra wideband (UWB) antennas are also demanded for some medical applications recently. One of the medical applications which require the UWB antennas is the microwave imaging of breast cancer. This imaging modality transmits lower power short microwave pulses (tens picoseconds to nanoseconds) into the body and detects the differentiated scattering due to the dielectric contrast between malignant and health tissues. A UWB compact antenna array is employed to conduct a 3D scanning through a so-called digital beamforming in space-time domain. In order to achieve high detection resolutions and good clutter rejection, the antennas with an impedance bandwidth 4-10GHz are usually employed as the elements in a condensed antenna array. So, small and low profile directional UWB antennas are desirable for this application. In addition, the antenna needs to have good radiation characteristics, i.e. consistent patterns over the entire operating bandwidth and good time-domain characteristics - minimal pulse distortion. Therefore, it still remains as an engineering challenge to design suitable UWB antennas for this application.

An RFID-enabled library management system using low-SAR smart bookshelves

Abstract: An intelligent Library Management System (LMS) based on the emerging UHF passive RFID technology is currently being designed in order to replace a traditional barcode system at the university's library. Primary objectives of the design include maximization of tag readability, localization of tagged items in the smart bookshelf, reduced spill-over energy to nearby shelves, and minimization of the Specific Absorption Rate (SAR) to nearby library users. Different types of shelf antennas were used and tested including evanescent-type antennas as well as far-field antennas. The antennas were designed, simulated, built, and tested in a realistic environment. HFSS and SEMCAD-X were used to evaluate radiation parameters and illustrate the radiation effects of near- and far-field antennas in the presence of the cabinet and library users.

Unidirectional uwb array antenna using leaf-shaped bowtie elements and flat reflector

Abstract: A study of a UWB array antenna is presented, which is composed of leaf-shaped bowtie radiating elements printed on a dielectric substrate. With the use of a flat reflector, the presented antenna has unidirectional radiation characteristics and higher directivity in comparison with omnidirectional UWB antennas. In the maximum radiation direction of the proposed antenna, the actual gain of 10.3-13.3 dBi is achieved over the frequency range of 4.1-10.0 GHz (-3 dB gain bandwidth of 91%).

Microstrip base station antennas for cellular communications

Abstract: Four base-station antenna products using microstrip technology have been developed for use in cellular communications. The antennas operate in the 800-900-MHz range and are designed to work in a 60 degrees sectored arrangement. The main product is a half-cylinder three-beam radome-enclosed antenna. There are three microstrip planar array panels within the half-cylindrical radome. Each microstrip planar array panel illuminates one 60 degrees sector, and all three panels fit into the half-cylindrical structure to provide RF coverage over 180 degrees . An electromechanical down-tilt actuator has also been designed into the structure to provide individual remote elevation adjustment to each panel. The antenna is in use in the Bell Cellular network. Its aesthetics and performance improvements in operations and maintenance have proven to be a big advantage in densely populated urban and suburban areas. >

A new type of antenna element for wide-band wide-angle dual polarized phased array antennas

Abstract: A new type of antenna element for wide-band (>1 octave) wide-angle dual polarized phased array antennas is presented The new array element has been designed with the goal to overcome the manufacturing and maintenance disadvantages with dual polarized tapered slot arrays The new element is especially suitable for arrays built by modules Numerically calculated infinite array performance and results from a small experimental with the new element is presented