this paper proposes a new smart antenna beamforming scheme based on electronically steerable parasitic array radiator (espar). the proposed method is capable of providing better capacity compared to the conventional espar. the termination of each antenna element in this structure comprises a pin diode in addition to a varactor. using pin diode besides the varactor provides more degrees of freed...

synthetic aperture radar (sar), which has been widely used for earth remote sensing, provides high resolution, day-and-night and weather-independent images for a multitude of applications. design of sar sensors has had some considerations, associated to sar systems issues (microwave propagation, antenna, orbit design and etc.). altitude and attitude errors of sar sensor have a direct effect on ...

this paper develops new results on the use of model predictive control to regulate the attitude of a ground station antenna. two degree of freedom az-el pedestal is considered as ground station antenna. permanent magnet synchronous motors are taken into consideration as the best choice for satisfaction of control objectives as actuators. the design is based on a two cascade controller consist o...

detection of stealth targets calls for employment of high-power radars which itself relies on usage of high-gain antennas like large parabolic reflectors. in the past few years, using of an array with many small reflectors instead of a large reflector antenna has been considered. this method provides enhanced eirp by a factor of n2 where n is the number of array antennas. regarding improvement ...

Meander line antenna (MLA) is an electrically small antenna which poses several performance related issues such as narrow bandwidth, high VSWR, low gain and high cross polarization levels. This paper describe the design ,simulation and development of meander line microstrip antenna at wireless band, the antenna was modeled using microstrip lines and S parameter for the antenna was obtained. The...

This paper proposes the rectangular microstrip patch antenna suitable to operate in different frequency bands. The rectangular microstrip patch antenna is designed and simulated using IE3D simulation software. The result obtained shows that the designed antenna is suitable for operation in four different frequency bands with bandwidth of 6.90%, 2.33%, 12.02% and 2.74% .The resonating behavior i...

Meander line antenna (MLA) is an electrically small antenna which poses several performance related issues such as narrow bandwidth, high VSWR, low gain and high cross polarization levels. This paper describe the design ,simulation and development of meander line microstrip antenna at wireless band, the antenna was modeled using microstrip lines and S parameter for the antenna was obtained. The...

Meander line antenna (MLA) is an electrically small antenna which poses several performance related issues such as narrow bandwidth, high VSWR, low gain and high cross polarization levels. This paper describe the design ,simulation and development of meander line microstrip antenna at wireless band, the antenna was modeled using microstrip lines and S parameter for the antenna was obtained. The...

Traditional design guidelines for broadband antennas do not always produce satisfactory performance for the desired frequency range of interest. In addition, the accurate prediction of the freespace antenna performance is not sufficient to determine if the antenna will meet a larger system requirement because the performance of the antenna can change significantly when it is installed on a plat...