This paper describes the beginning and evolution of microwave rotational spectroscopic research starting in 1954 at the National Bureau of Standards (NBS), located at that time in Washington, DC, through the present at NIST in Gaithersburg, MD. David Lide was hired in 1954 to start this research employing Stark modulated waveguide septum cells. When Donald R. Johnson joined the lab in 1968, he ...

an experimental study was carried out on the wake of a cylinder on the back of which a plate is installed parallel to the fluid flow, with different terminal angles, where the reynolds number is 50000. at the end of the plate, blades with the height of 0.25 equal to the cylinder diameter and with 45, 90 and 135 degrees angle from the horizon, are installed where the cylinder diameter is equal t...

An all-metallic multi-layered parallel-plate slot array antenna operated in the 60-GHz band with wide impedance bandwidth and high-gain characteristics is proposed. The $16\,{\times }\,16$ -slot composed of notation="LaTeX">$2\,{\time...

The plate-laminated waveguide slot array antenna is a high-efficiency and wide-band antenna in the millimeterwave band. However, in the conventional corporate-feed circuit, the number of radiating elements is limited to be a power of two by using a cascade of T-junctions. In this paper, we propose the corporate-feed with a cross junction and an asymmetric Tjunction for 12×16 elements. The bandw...

Plate-shaped (DTA)2Cu2I4 crystals with green-yellow emissions, 0D structures and waveguide behavior were prepared by the employment of long alkyl chain molecules.

This paper describes a new, compact, waveguide thermal isolator. The isolator is based on a recently developed microwave bandgap joint, a periodic structure which suppresses microwave fields propagating between two parallel conducting surfaces. When such a structure is placed between a pair of waveguide flanges, the flanges can be separated by a few percent of a wavelength before the leakage an...

The method of parallel end-butt coupling has been used to couple GaAs laser diodes to Ta (2)O(5) thin film waveguides. Theoretical caluclations predict that a coupling efficiency into the lowest order waveguide mode of 90% is achievable if the thicknesses of the waveguide (t(g)) and the laser light emitting layer (t(L)) are equal. Experimentally, efficiencies as high as 45.1% have been measured...

A high precision measurement technique for characterizing the propagation loss in silica low-loss optical waveguides, based on measuring the contrast of a Fabry-Perot cavity, is demonstrated. The cavity consists of the waveguide coupled to two polarization-maintaining fibers, each end facet coated with dielectric mirrors, leaving the reflectivity as an adjustable parameter. The contrast is meas...