Antennas have come to play a significant role in the reception and transmission of electromagnetic radiation or signals which turn improved scientific research various areas where they been used. Astronomy is not left out; as study everything beyond earth’s atmosphere, useful travel great distances reach us. Hence need for equipment detect such signals. The Helical Antenna known possess high ga...

The influence of semi-planar chiral metamaterial (CMM) structures on the important characteristics of circularly polarized (CP) antennas is investigated in this paper. Based on this idea, CP planar two-arm Archimedean spiral (ARSPL) antenna and helical antenna are designed and the effects of chiral covers on their gain (or directivity), axial-ratio (AR), and return loss are considered. The resu...

This paper is a review of amateur-built high-directivity wire antennas, for wireless local area network (WLAN), operating at 2.4-GHz frequency range. Those antennas can be deployed for range extension and interference reduction, for example. Covered in this review are a biquad antenna with reflector, Yagi-Uda antenna, and helical antenna. The distinctive feature of these antennas is their ease ...

We report a development and fabrication of an folded waveguide (FWG) antenna to produce and heat the plasma via ion Bernstein wave on the Large Helical Device (LHD) in the ion cyclotron range of frequency (ICRF). This antenna is 428 mm in height, 1050 mm in width and 3950 mm in length with 23 vanes and 24 folds. It will be installed to the horizontal vacuum port with an inclination angle of 38....

Two-dimensional images of the ionized argon light of a helicon discharge are made both along and across the magnetic field with various antenna configurations. Two antennas, a Nagoya type III and a helical antenna, are used to create a magnetized RF plasma with density in the range n ≤ 5× 1013 cm−3. A CCD camera with a 488 nm bandpass filter is used to image the plasma as magnetic field and pow...

This article surveys the research of the Evolvable Systems Group at NASA Ames Research Center. Over the past few years, our group has developed the ability to use evolutionary algorithms in a variety of NASA applications ranging from spacecraft antenna design, fault tolerance for programmable logic chips, atomic force field parameter fitting, analog circuit design, and earth observing satellite...