Recently, much attention has been focused on beams carrying orbital angular momentum (OAM) for radio communication. Here we experimentally demonstrate a planar-spiral phase plate (planar-SPP) for generating arbitrary mixed OAM beams. This proposed planar-SPP uses the concept of transmit array antenna having a perforated substrate to control the outputting phase for generating beams carrying OAM...

Abstract—This work presents the results of the synthesis of a lightweight inexpensive reconfigurable planar array antenna. The antenna structure is based on four circular patches. The sources points and some discontinuities on the patches can be electronically reconfigured by means of radio-frequency (RF) switches in order to modify the radiation pattern. In particular, the main lobe could be s...

lenses are often used to converge electromagnetic wave namely they convert incident phase front of feed antenna to a flat phase front. together, the lens and the feed create an electrically large aperture antenna. flat lenses provide the cost and weight benefits of the reflect-arrays, while maintaining the advantages of a lens antenna. these lenses use an array of unit-cells which are excited b...

This research involves the overlaps of antenna theory, fractal geometry, and numerical calculations. Its goal is to investigate how random or periodic antenna array geometry can be improved through the use of fractals. Using a program we developed in Matlab, we plotted the radiation of linear/planar antenna arrays. We were able to correctly analyze radiation of three two-dimensional arrays. Ano...

The nulling of interferences or jammers impinging on a planar antenna array is addressed by means of an efficient adaptive control strategy based on a Genetic Algorithm. Each element of the array is uniformly weighted and the nulling feature is yielded by controlling a set of radiofrequency switches that connect or disconnect the elements from the beam forming network. Under the assumption that...

An innovative method for antenna arrays beam configuration is presented. In the proposed method, every element of the array is connected to its feed through a switch, so that it can be active or passive, depending on the switch position. Pattern reconfigurability is achieved by appropriately switching on or off the array elements. The optimal configuration of the switches for each of the radiat...

High-gain and large-aperture antennas with fixed beams are required to achieve high S/N ratio for point-to-point high-speed data-communication systems in the millimeter-wave band. Furthermore, beam-scanning antennas are attractive to cover wide angle with high gain for applications of high-speed data-communication systems and high-resolution sensing systems. High-gain pencil-beam antennas are u...

Antenna array distributions and their associated patterns are now designed on physical principles, based on placement of zeros of the array polynomial. An overview of the synthesis processes is given. Robust and low Q distributions for linear arrays and circular planar arrays, that provide variable side lobe level pencil beam patterns, are treated in detail. Associated difference patterns are i...