In this letter, a concept of high-gain circularly polarized X-band antenna employing partially reflecting surface (PRS) has been presented. the initial analysis, influence parasitic element size in PRS structure on radiation pattern parameters investigated and optimal arrangement elements identified. The proposed provides wide bandwidth return loss above 10 dB 20% (8–9.8 GHz) circular polarizat...

We realize a laser with a cloud of cold rubidium atoms as gain medium, placed in a low-finesse cavity. Three different regimes of laser emission are observed corresponding, respectively, to Mollow, Raman, and four-wave mixing mechanisms. We measure an output power of up to 300 microW and present the main properties of these different lasers in each regime.

We study theoretically the phenomenon of enhanced backscattering ~EBS! from a bulk disordered gain medium due to the presence of a dye and a pump beam. We show that the presence of the gain, in combination with the effect of saturation, can dramatically sharpen the EBS peak function. In the particular case of a point source incidence for the probe beam along with the presence of a plane-wave pu...

We present a variety of dissipative solitons and breathing modes in a medium with localized gain and homogeneous linear dissipation. The system possesses a number of unusual properties, like exponentially localized modes in both focusing and defocusing media, existence of modes in focusing media at negative propagation constant values, simultaneous existence of stable symmetric and antisymmetri...

Abstract A flexible microstrip antenna is a compact that can be coupled with the skin. However, such antennas require to an intermediate matching liquid medium which makes bulky, complicated, and expensive. Body area network devices are wearable wireless devices/sensors used get information of patient’s health in terms physiological changes irrespective location. layer made Polyethylene chosen ...