A comprehensive program of study and measurement of the Haystack reflector has been conducted, resulting in a performance improvement of approximately 40 percent. A stochastic approach to data taking and analysis combined with the benefits of an on-site computer provided analytical control of the adjustment operation, and at the same time assured a short reaction time between receipt of the raw...

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 ...

Selection of the most suitable substrate for a Microstrip antenna is a matter of prime importance. This is because many limitations of the microstrip antenna such as high return loss, low gain and low efficiency can be overcome by selecting an appropriate substrate for fabrication of the antenna, without shifting the resonant frequency significantly. The substate properties such as its dielectr...

A dual-polarized Ka-band feed based on gap waveguide (GW) technology for an ultra-high-gain reflector antenna is presented. The provides SUM-beams data transfer and DIFF-beams tracking. whole composed of the a dual-reflector Cassegraine antenna. has been prototyped, measured reflection coefficients horizontally vertically polarized SUM-beam ports are below -10 dB -8 over 30.8-38 GHz, respective...

In this research paper, a slotted coaxial line fed cross dipole excitation structure for short backfire antenna is proposed and developed to achieve reconfigurable circular polarization. The cross dipole, which is fed by the slotted coaxial line, consists of two orthogonal dipoles. The dipoles are mounted on the outer conductor of the coaxial line. A unique technique is developed to generate re...

We report a precision and fast wavelength tuning technique demonstrated for a digital-supermode distributed Bragg reflector laser. The laser was dynamically offset-locked to a frequency-stabilized master laser using an optical phase-locked loop, enabling precision fast tuning to and from any frequencies within a ~40-GHz tuning range. The offset frequency noise was suppressed to the statically o...

A two-dimensional (2D) diffraction model for the calculation of the diffraction field in 2D space and its applications to terahertz parallel-plate waveguide power splitters are proposed in this paper. Compared with the Huygens-Fresnel principle in three-dimensional (3D) space, the proposed model provides an approximate analytical expression to calculate the diffraction field in 2D space. The di...