This paper presents a new design of a CPW-Fed multi bands planar antenna. This antenna can be integrated easily with passive and active elements. The proposed antenna is suitable to operate for GPS, PCS and WiMAX bands. Its entire area is 52.3x52.6mm2 and is employed on an FR-4 epoxy substrate and fed by a 50 Ohm coplanar line. The antenna parameters have been analyzed and optimized by using AD...

This article discusses the direction-of-arrival estimation of plane waves impinging on an antenna array. Special attention is devoted to the incorporation of mutual coupling between the antenna elements of the array into the estimation algorithm. More complex antenna array configurations are considered, which have a better performance for directionof-arrival estimation. Keywords—Direction-of-ar...

A novel phase conjugator for active retrodirective array applications is presented. The circuit provides conversion gain as well as phase conjugating operation by using active devices, and results in a simple and compact design by using a common port for RF and IF signals. Measurement results indicate 3.2 dB conversion gain with RF-IF isolation of 20 dB. This phase conjugator can be used as a c...

A typical multimedia via satellite transmission needs to cover, from a geostationary orbit, a large terrestrial zone with 40 to 50 semi-contiguous beams, for very high gain & re-using 10 to 12 times the same frequency resource, by dividing the available bandwidth in 4 sub-bands, 1 spot-beam over 4. Such multi-beam antenna much increases the System capacity, for providing broadband services dire...

We investigate the behaviour of MIMO capacity when the size of the antenna array is constrained. By increasing the number of antennas within a small region in space the antenna array becomes dense and spatial correlation inhibits capacity growth. A theoretically derived antenna saturation point is shown to exist for dense array MIMO systems, at which there is no capacity growth with increasing ...

A conventional active phased array antenna (APAA) for a military purpose is composed of modules each of which includes a radiator, a high power amplifier (HPA), a low noise amplifier (LNA), a phase shifter and combiners on a printed circuit board (PCB). Therefore, such a APAA is thicker than the longitudinal size of the PCB. Several attempts of planar APAAs were proposed to overcome the disadva...

In this paper, an antenna array structure consisting of a reflector plate and a number of printed dipole radiation elements is investigated. This antenna array implementation is suitable for the globally available 2.4GHz and 5GHz ISM frequency band facilitating a variety of wireless applications. S-parameters and radiation characteristics are simulated and measured in details. The impact of the...

we propose a new generation of unbiased (bias-free) antenna-less cw thz photomixer emitters array made of asymmetric msm gratings with subwavelength pitch, operating in optical near-field regime. we take advantage of the size effects in near-field optics and electrostatics to demonstrate the possibility of enhancing the thz power by four orders of magnitude, as compared with a similar array of ...

One of the important issues in many of array systems such as Radar, Sonar, Mobile, and satellite telecommunications is the estimation of DOA of narrowband received signal. CRB is very important in evaluation of parameter estimation. CRB is the lower bound estimation error variance for any unbiased estimation. In this paper, the array antenna with equal distance arrays is extended in two separat...

We propose a push/pull origami antenna, transformable between a single antenna element and a three-element array. In limited space, the proposed origami antenna can work as a single antenna. When the space is not limited and a higher gain is required, the proposed origami antenna can be transformed to a series antenna array by pulling the frame. In order to push the antenna array back to a sing...