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.

Side lobe level optimization in phased array antennas using genetic algorithm

Abstract: The sidelobe level (SLL) of linear and planar phased arrays is optimized using a genetic algorithm (GA). The amplitude and phase of the current of the antennas are all taken as variables to be controlled. As a final example, the design specifications for a 100 element linear array and a 100 element planar array are given. The linear and planar arrays are also optimized over scan angle. Simulation results are presented as several plots. Successful applications show that the GA can be used as a general tool for pattern synthesis of arbitrary arrays.

Design of non-uniform antenna arrays using genetic algorithm

Abstract: The performance of a single-element antenna is somewhat limited. To obtain high directivity, narrow beamwidth, low side-lobes, point-to-point and preferred-coverage pattern characteristics, etc., antenna arrays are used. An antenna array is an assembly of individual radiating antennas in an electrical and geometrical configuration. Nowadays, antenna arrays appear in wireless terminals and smart antennas, so robust and efficient array design is increasingly becoming necessary. In antenna array design, it is frequently desirable to achieve both a narrow beamwidth and a low side-lobe level. In linear antenna arrays, a uniform array (having uniform inter-element spacing and uniform amplitude excitation) yields the smallest beamwidth and hence the highest directivity. It is followed, in order, by the Dolph-Chebyshev and Binomial arrays. In contrast, Binomial arrays usually possess the smallest side-lobes followed, in order, by the Dolph-Chebyshev and uniform arrays. Binomial and Dolph-Chebyshev arrays are typical examples of non-uniform arrays. Non-uniform linear antenna arrays have uniform inter-element spacing and non-uniform amplitude distributions. In this paper we deal only with linear arrays and it is shown that using genetic algorithm it is possible to design a non-uniform array that approximates the beamwidth of a uniform array and having smaller side-lobe level than the Dolph-Chebyshev array. The result is that the designed antenna array exhibits the largest directivity as compared to the uniform, Binomial and Dolph-Chebyshev arrays. In the design, the genetic algorithm is employed to generate the excitation amplitudes of the antenna array.

The performance of transistor fed monopoles in active antennas

Abstract: The performance of radiating elements in the form of monopoles and driven by transistors is examined theoretically and experimentally. A single element comprising a printed monopole over a ground plane and fed at its terminals by a microwave transistor is shown to have superior frequency characteristics compared to the passive element. Using a two-element array configuration, it is verified that the mutual impedance values are suppressed. The improved individual characteristics of the active elements together with their mutual behavior combine to produce a significantly improved frequency performance of the array. The results presented suggest that the transistorized array principle offers a means both of maintaining directivity of a transmitter, and discriminating against interfering sources by a receiver, over a greater frequency band.

Wide field-of-view fixed body conformal antenna direction finding array

Abstract: A fixed body wide field-of-view conformal antenna array suitable for broadband precision direction finding on missile platforms. The array is configured as multiple sub-arrays of spiral antennas that cover particular regions within the desired field-of-view of the entire array. A lower cost, more reliable and more accurate direction finding solution for missile needs is provided, primarily by the elimination of conventional radomes and antenna gimbal structures. The array can be configured to include multi-mode sensors.