Active antenna

About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.

Nonlinear Active Antenna Array Dynamics and Load Analysis

Abstract: This paper describes a method used to determine the nonlinear dynamics of an array of two mutually coupled transmitting active antenna elements. The model is cast in terms of amplitude and phase dynamics and array entrained frequency condition in the situation where the array elements are spatially coupled by mutual injection locking. The work reported here treats phase and amplitude dynamics in a coupled manner. The model presented can accommodate unlike active antenna element characteristics such as power output and frequency of operation as well as permiltting unequal element spacing. In addition to the above, a separate load pulling analysis is given for the calculation of the frequency and power variation of an active antenna operated in the presence of a reflecting metallic surface.

Active antenna with interleaved arrays of antenna elements

Abstract: An antenna has multiple arrays of radiating elements and includes a plurality of single channel power amplifiers, with each amplifier electrically connected with an array. The radiating elements of the arrays are interleaved so that radiation from the arrays combines at a distance from the antenna.

Novel wideband active microstrip antennas using distributed frequency multiplexers or de-multiplexers

Abstract: In this article, a novel approach is introduced for the design of wideband antennas in a specified frequency bandwidth (BW). In the proposed approach, the frequency BW is divided into some sub-bands. Then, the narrowband antennas are designed for the consecutive frequency sub-bands, and the antennas are connected together by a proposed active circuit, so that their frequency BWs combined. The proposed active circuit may be used to connect as many as antenna needed for the design. An active microstrip antenna is designed for the frequency BW of 4–10 GHz with a gain better than 5 dB by the proposed method. Fabrication and measurement results show the effectiveness of the proposed methodology. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.

Reconfigurable active computational beamforming antenna

Abstract: The invention relates to an apparatus for processing the data from a plurality of digital signals (71) for a system for transmitting and/or receiving active antenna RF signals capable of forming at least one beam (98) by means of computation using a plurality of combiners (501, 502, 503, 511, 512, 513). The apparatus comprises means for processing the digital signal data over a plurality of computational planes in parallel (501-503 and 511-513) and separately between each computational plane. The invention can be used for any type of computational beamforming antenna and preferably for onboard antennas for use in satellites.

Biologically inspired antenna array design using Ormia modeling

Abstract: This chapter describes the design of a small-size antenna array having high direction of arrival (DOA) estimation accuracy and radiation performance, inspired by female Ormia ochracea’s coupled ears. Female Ormias are able to locate male crickets’ call accurately, for reproduction purposes, despite the small distance between its ears compared with the incoming wavelength. This phenomenon has been explained by the mechanical coupling between the Ormia’s ears, modeled by a pair of differential equations. In this chapter, we first solve the differential equations governing the Ormia ochracea’s ear response and propose to convert the response to prespecified radio frequencies. We consider passive and active transmitting antenna arrays. First, to obtain a passive antenna array with biologically inspired coupling (BIC), using the converted response, we implement the BIC as a multi-input multi-output filter on a uniform linear antenna array output. We derive the maximum likelihood estimates of source DOAs and compute the corresponding Cramer–Rao bound on the DOA estimation error as a performance measure. Then, to obtain an active antenna array with BIC, together with the undesired electromagnetic coupling among the array elements (due to their proximity), we apply the BIC in the antenna array factor. We assume finite-length dipoles as the antenna elements and compute the radiation intensity, and accordingly the directivity gain, half-power beam width, and side lobe level as radiation performance measures for this antenna system with BIC. For both passive and active antenna arrays, we propose an algorithm to optimally choose the BIC for maximum localization and radiation performance. With numerical examples, we demonstrate the improvement due to the BIC.