Abstract. Reflector antennas are characterized by very high gains (30 dB and higher) and narrow main beams. They are widely used in satellite and line-of-sight microwave communications as well as in radar. Reflector antennas operate on principles known long ago from the theory of geometrical optics. The first reflector system was made by Hertz back in 1888 (a cylindrical reflector fed by a dipo...

We discuss combining gravitational lensing of galaxies and the cosmic microwave background (CMB) by clusters to measure cosmographic distance ratios, and hence dark energy parameters. Advantages to using the CMB as the second source plane, instead of galaxies, include: a welldetermined source distance, a longer lever arm for distance ratios, typically up to an order of magnitude higher sensitiv...

The design, fabrication and characterization of a novel metamaterial absorber based camera with subwavelength spatial resolution are investigated. The proposed camera is featured with simple and lightweight design, easy portability, low cost, high resolution and sensitivity, and minimal image interference or distortion to the original field distribution. The imaging capability of the proposed c...

We experimentally and theoretically demonstrate the negative refraction and focusing of electromagnetic (EM) waves by twodimensional photonic crystal slabs at microwave frequencies. The negative refraction is observed both for transverse magnetic (TM) and transverse electric (TE) polarized incident EM waves. Gaussian beam shifting method is used to verify the negative refractive index. The Subw...

Gradient index lens antennas find their application in modern wireless communication including radar systems, satellite communication, etc. They can ensure highly directional beamforming, support multibeam operations and beam steering capabilities within a wide angle of view. The development 3D printing technologies enables the implementation complex gradient refractive distribution with high a...

Millimeter-wave (mmWave) MIMO with large antenna array has attracted considerable interests from academic and industry communities, as it can provide larger bandwidth and higher spectrum efficiency. However, with hundreds of antennas, the number of radio frequency (RF) chains required by mmWave MIMO is also huge, leading to unaffordable hardware cost and power consumption in practice. In this p...

  Background: Increased oxygen free radical and reduced glutathione level in the eye lens are important risk factor for cataract formation. The antioxidative property and increasing cellular and extra cellular glutathione level have been reported by several herbal medicines including silymarin.  Objective: In present interventional study Silybum marianum L. seed extract (silymarin) was tested a...

f(R) gravity, capable of driving the late-time acceleration of the universe, is emerging as a promising alternative to dark energy. Various f(R) gravity models have been intensively tested against probes of the expansion history, including type Ia supernovae (SNIa), the cosmic microwave background (CMB) and baryon acoustic oscillations (BAO). In this paper we propose to use the statistical lens...

Introduction: Critical organs and structures may receive significant amounts of irradiation even if they are not the target of radiotherapy or located outside the treatment field. Although the sensitive thyroid gland and lens are not directly the targets of treatment, they can be affected by irradiation during the treatment of tumours in head and neck region. The purpose of thi...

Introduction: Among the components of the extracellular matrix (ECM) and basement membrane (BM), laminitis heterotrimeric glycoprotein (laminin) and collagen type IV are the most important. In a previous study we have examined the role of collagen type IV in the developing lens capsule. The present study aims to determine the appearance and distribution of laminin in the BM and ECM of lenses ...