A practical normal-mode helical antenna array together with a new method for the compensation of mutual coupling effect is proposed for the efficient adaptive nulling of interferences in a mobile communication environment. The helical antenna array is shown to be able to generate deeper nulls than an equivalent monopole antenna array in the presence of mutual coupling effect. The helical antenn...

A compact size, multiband 2x2 array of circular microstrip antenna has been proposed. The antenna array consists of Genetic Algorithm (GA)optimized, annular slotted circular microstrip antenna elements using probe feed. The spacing of elements has also been optimized using GA in the two directions. The performance of the antenna array has been studied with different shape parameters. The optimi...

Date The final copy of this thesis has been examined by the signatories; and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline iii Thesis directed by Professor Zoya Popovi´c In wireless communications systems, the transmit front-end consumes a large fraction of the total available power. In particular, the power...

In this research, a sub-array preconditioner is applied to improve the convergence of conjugate gradient (CG) iterative solver in the fast multipole method and fast Fourier transform (FMM-FFT) implementation on a large-scale finite periodic array antenna with arbitrary geometry elements. The performance of the sub-array preconditioner is compared with the near-group preconditioner in the array ...

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...

In multi-user beamforming systems, the inter-user interference are controlled by spatial filtering. Since the implementation of digital beamforming is difficult due to high hardware cost of large array system, the analog beamforming system with one phase shifter at each antenna element is considered with antenna selection scheme. However, the beamwidth is not sufficiently narrow to perfectly re...

Microstrip antenna arrays are one of the popular antenna configurations for nowadays wireless communication system. The paper proposes a compact novel design of multiple elements electromagnetically coupled stacked antenna array which operates in Cband. The antenna resonates at 6 GHz and shows bandwidth of 521 MHz with 5.84dBi gain. The proposed antenna shows the ECC to be 0.03 which indicated ...

This paper describes the design, implementation and characterization of a high efficiency 10-GHz amplifier antenna array for spatial power combining. An average drain efficiency of 70% at 162 W EIRP, or about 1.5 W of transmitted power, is measured for an array of 16 amplifiers consisting of four 4-element subarays. The power combining efficiency of the 16-element array is above 79%. The active...

Office of Naval Research (ONR) of U.S.A navy has been carrying out research about advanced multifunction radio frequency concept (AMRFC) to apply the Multifunction Electronic Warfare & Electronic Support (MFEW ES) system to the future navy battleship [1]. In order to that conventional radar and communication antennas need to be active phased array antennas that can provide multi-functions such ...

As a result of recent technical and regulatory developments, the millimeter wave (mmw) frequency band (30GHz – 300 GHz) is being adopted for a wide range of applications. Based on array signal processing technologies used for 4G and MIMO, companies are developing small active array antennas operating throughout the millimeter-wave bands. These arrays may include radiating elements and feed stru...