The digital beamforming antenna array is one of the most important components in wireless communication systems used in defence applications to improve the system capacity and spectral efficiency. The pattern synthesis of active antenna array is required in many defence applications like radar, satellite communication, sonar, mobile communication etc., where interference signals are considered ...

In this paper, an optimal approach to design wideband tapped-delay line (TDL) array antenna is proposed. This approach lets us control the array angular and frequency response over a wide frequency band. To this end, some design restrictions are defined and a multi-objective optimization problem is constructed by putting the individual restrictions together. The optimal weights of the TDL proce...

an active antenna for transmitter application in s frequency band is designed and analyzed using harmonic balance technique which is based on the nonlinear model of active devices. in this active antenna, the amplifier is integrated with the radiator which is a rectangular patch antenna. this patch antenna is analyzed employing full-wave momentum method. by applying nonlinear model of transisto...

In this chapter, we describe a compact array antenna. Beamforming is achieved by tuning the load reactances at parasitic elements surrounding the active central element. The existing beam forming algorithms for this reactively controlled parasitic array antennas require long training time. In comparison with these algorithms, a faster beamforming algorithm, based on simultaneous perturbation st...

Low-cost antenna systems are important issues of the recent and the future flexible wireless communication systems. The most flexible satellite to ground/airplane communication systems are based on the phased-array antenna technology. However, the cost of phased array antenna is related to the number of active elements, and the present systems are too expensive for many commercial/military appl...

different methods exists for jamming mitigation and we should choose a method based an the jammer type and other parameters. one of the jammers is narrow band fm jammer and we use subspace projection techniques for the suppression of this type of jammer. in subspace projection technique, we estimate the if of signals and construct the subspace vector that is orthogonal to jammer vector by incre...

A one-dimensional, dual frequency, active retrodirective array is proposed for wireless power transfer applications. Microstrip circular patch antennas with four shorting pins are used as array elements to suppress surface waves. The proposed design eliminates undesired coupling between array elements due to surface waves present in conventional microstrip antenna arrays in order to improve arr...