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.

Practical Antenna Handbook

Abstract: This edition contains BASIC computer programs for antenna design and impedance matching, expanded coverage of long-wire directional antennas and radio-wave propagation theory, and new material on small loop direction-finding antennas. It presents practical projects, providing nuts-and-bolts information on an array of antenna types, including: high frequency dipole, vertically polarized HF, multi-band and tunable wire, hidden and limited-space, directional-phased vertical and directional beam, VHF/UHF transmitting and receiving antennas, antennas for shortwave reception, microwave antennas and mobile, marine and emergency antennas. Also explained are circuits and methods for matching antenna load impedance to an RF source or transmission line, antenna measurement and adjustment methods, antenna measurement and adjustment methods, antenna grounding techniques and how to use the Smith chart as a problem-solving device.

Low-Profile PIFA Array Antennas for UHF Band RFID Tags Mountable on Metallic Objects

Abstract: Two PIFA array antennas, designed for UHF band RFID tags mountable on metallic objects, are presented in this paper. The proposed array antennas are fabricated on a very thin substrate with a thickness of 0.8 mm. The first array that has shorting pins placed at the outer edges of PIFAs is fed by two quarter-wavelength microstrip lines. This array has a simple feeding structure, which is its main advantage. Meanwhile, the second array has shorting pins located at the inner edges of PIFAs, and incorporating additional matching stubs into the quarter-wavelength microstrip lines is needed to achieve complex impedance matching, which can offer a broad bandwidth. By properly selecting the spacing between the PIFAs, an enhanced antenna gain and a good reading-range performance can be obtained for both array antennas. In addition, the two array antennas proposed are studied mounted on differently sized metallic plates. It is found that there is a negligible influence of the metal-plate size on the reading range is found for the second array antenna, which is superior to the first one.

A 108–114 GHz 4 $\,\times\,$ 4 Wafer-Scale Phased Array Transmitter With High-Efficiency On-Chip Antennas

Abstract: This paper presents a W-band wafer-scale phased- array transmitter with high-efficiency on-chip antennas. The 4 × 4 array is based on an RF beamforming architecture with an equiphase distribution network and phased shifters placed on every element. The differential on-chip antennas are implemented using a 100 μm thick quartz superstrate and with a simulated efficiency of ~ 45% at 110 GHz. The phased array is designed with low mutual coupling between the elements and results in a stable active antenna impedance versus scan angle. The phased array is built in the Jazz SBC18H3 SiGe BiCMOS process, and is 6.5 × 6.0 mm2. Measurements show two-dimensional pattern scanning capabilities with a directivity of 17.0 dB, an array gain of ~26.5 dB at 110 GHz, and an EIRP of 23-25 dBm at 108-114 GHz. The power consumption is 3.4 W from a 1.9 V supply. To our knowledge, this work represents the first W-band wafer-scale phased array to-date. The application areas are in point-to-point communication systems in the 100-120 GHz range.

Direction of Arrival Estimation Using Directive Antennas in Uniform Circular Arrays

Abstract: The effect of directional antenna elements in uniform circular arrays (UCAs) for direction of arrival (DOA) estimation is studied in this paper. While the vast majority of previous work assumes isotropic antenna elements or omnidirectional dipoles, this work demonstrates that improved DOA estimation accuracy and increased bandwidth is achievable with appropriately-designed directional antennas. The Cramer–Rao Lower Bound (CRLB) is derived for UCAs with directional antennas and is compared to isotropic antennas for 4- and 8-element arrays using a theoretical radiation pattern. The directivity that minimizes the CRLB is identified and microstrip patch antennas approximating the optimal theoretical gain pattern are designed to compare the resulting DOA estimation accuracy with a UCA using dipole antenna elements. Simulation results show improved DOA estimation accuracy and robustness using microstrip patch antennas as opposed to conventional dipoles. Additionally, it is shown that the bandwidth of a UCA for DOA estimation is limited only by the broadband characteristics of the directional antenna elements and not by the electrical size of the array as is the case with omnidirectional antennas.

Array antenna device and radio communication device

Abstract: An array antenna device includes a plurality of slot array antennas which are arranged and each of which includes a plurality of slot antennas and a radiation surface, which is formed to be conformal, and a plurality of waveguides each of which supplies respective power to each of the slot array antennas. After bodies of the waveguides are formed by a resin molding method, surface treatment is performed with respect to inner surfaces of the waveguides with plating.