Spatially heterogeneous intensities of environmental signals are common in nature, being caused, e.g., by rugged or curved surfaces leading to varying angles of incidence and intensities. In this work, we perform numerical studies of one-dimensional arrays of coupled phase oscillators driven by a periodic signal with spatially heterogeneous amplitude, considering both random and gradual amplitu...

In this paper, a frequency reconfigurable multiple-input-multiple-output (MIMO) antenna has been described. The idea of the design is to form reconfigurable MIMO antenna by the development of two-port antenna that are identical to each other and pin diodes are used to achieve the frequency reconfigurability. The design of the canonical element consists of compact folded slots with one pin diode...

Microstrip antennas are widely used in a broad range of military and commercial applications due to its low cost, low profile, easy fabrication and light weight. But this kind of antenna also has some drawbacks. For example, the diffraction of surface waves at the edge of finite grounded substrate decreases the antenna efficiency and degrades the antenna pattern [1]. In the phased array antenna...

The construction of a low-cost and reliable array antenna system is required to facilitate the practical use of the adaptive antenna in the mobile communication field. The array antenna system can be verified by DOA (Direction of Arrival) estimation. This dissertation describes the attempt to achieve a high-precision adaptive antenna and the examination of this device, which suppresses the numb...

An efficient design procedure for a radial waveguide feed network for an array antenna, whose radiating elements are pin-fed, is presented. A model of the feed network is considered and relevant design parameters are expressed by simple analytic terms. To facilitate the design of the feed, a useful coupling chart for a pin-loaded radial waveguide is suggested. It shows graphically the dependenc...

In this paper, suppression of mutual coupling is achieved using compact waveguided metamaterials (WG-MTMs) in between elements of a densely packed microstrip array. Both the E-plane internally folded complementary split ring resonator and the H-plane internally folded complementary split ring resonator are employed to reduce the mutual coupling between adjacent elements. Coupling suppression of...