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.

Front-to-Back Ratio Enhancement of Planar Printed Antennas by Means of Artificial Dielectric Layers

Abstract: In this paper, we investigate the use of artificial dielectric layers (ADLs) as a mean to enhance front-to-back radiation ratio in printed, planar antennas. These artificially engineered substrates can be designed to be anisotropic and present high dielectric constants for the waves propagating orthogonal to metallic layers. However, the dielectric constants is as low as that of the host material for the waves that propagates towards grazing direction, and thus surface waves due to multiple reflections at the dielectric air interface are not enhanced. A simple qualitative description of this concept is followed by the presentation of a experimentally verified prototype which clearly highlights the potential advantages of the proposed ADL for antenna applications.

GPS/GNSS Antennas

Abstract: This practical resource provides a current and comprehensive treatment of GPS/GNSS antennas, taking into account modernized systems and new and developing applications. The book presents a number of key applications, describing corresponding receiver architectures and antenna details. You find important discussions on antenna characteristics, including theory of operation, gain, bandwidth, polarization, phase center, mutual coupling effects, and integration with active components. Moreover, you get expert guidance on the design of adaptive arrays and signal processing techniques used to mitigate interference such as jamming. Addressing critical GNSS antenna high precision requirements, this in-depth book explains the relationships between antenna gain, satellite visibility, geometric dilution of precision, and the carrier-to-noise density ratio. The book delineates requirements for both dual-band and tri-band antennas. You get detailed coverage of a wide range of antenna designs, including microstrip patch, quadrafilar helix, axial mode helix, spiral, inverted L, and planar inverted F antennas. Moreover, you find a discussion on new magnetic metamaterialu substrates and other dielectric substrate materials. Further, this comprehensive book presents designs for very compact GNSS antennas for personal handheld devices and automobiles.

Conformal phased array with beam forming for airborne satellite communication

Abstract: For enhanced communication on board of aircraft novel antenna systems with broadband satellite-based capabilities are required. The installation of such systems on board of aircraft requires the development of a very low-profile aircraft antenna, which can point to satellites anywhere in the upper hemisphere. To this end, phased array antennas which are conformal to the aircraft fuselage are attractive. In this paper two key aspects of conformal phased array antenna arrays are addressed: the development of a broadband Ku-band antenna and the beam synthesis for conformal array antennas. The antenna elements of the conformal array are stacked patch antennas with dual linear polarization which have sufficient bandwidth. For beam forming synthesis a method based on a truncated singular value decomposition is proposed.

Phase synthesis of conformal array antennas

Abstract: A new phase synthesis method for planar and conformal arrays is presented. The method is based on approximate linearized equations for small phase changes in the excitations, which can be determined by the least-squares method and used iteratively to obtain the final solutions for the excitation phases. Several different kinds of contoured beams can be used in the same array by using only phase shifters in the elements, as demonstrated in the calculated synthesis examples.

3D beamforming designs for Single User MISO systems

Abstract: In this paper, we study a transmit beamforming technique for multiple input single output downlink single-user systems with three dimensional antennas where a transmit antenna gain is determined in three dimensional coordinates. In general, the transmit antenna gain is controlled by adjusting the boresight of antennas in directional antennas. To derive the optimal tilting angles for the directional antenna systems, we provide the probability density functions (PDF) of the three dimensional user distribution. Furthermore, based on the PDF, the analysis for the average rates of passive and active antenna systems is presented. Simulation results verify the accuracy of the performance analysis.