Showing papers by "Constantine A. Balanis published in 1976"
Patent•
06 Apr 1976
TL;DR: In this paper, a method for remotely mapping coal beds prior to and during in situ gasification operations is proposed, which is achieved by emplacing highly directional electromagnetic wave transmitters and receivers in bore holes penetrating the coal beds and then mapping the anomalies surrounding each bore hole by selectively rotating and vertically displacing the directional transmitter in a transmitting mode within the bore hole.
Abstract: The present invention is directed to a method for remotely mapping subterranean coal beds prior to and during in situ gasification operations. This method is achieved by emplacing highly directional electromagnetic wave transmitters and receivers in bore holes penetrating the coal beds and then mapping the anomalies surrounding each bore hole by selectively rotating and vertically displacing the directional transmitter in a transmitting mode within the bore hole, and thereafter, initiating the gasification of the coal at bore holes separate from those containing the transmitters and receivers and then utilizing the latter for monitoring the burn front as it progresses toward the transmitters and receivers.
19 citations
TL;DR: In this article, the dielectric constant and loss tangent values of coal samples were computed from measurements made at microwave frequencies (8.2-12.4 GHz) using two different waveguide methods.
Abstract: In this investigation dielectric constant and loss tangent values of coal samples were computed from measurements made at microwave frequencies (8.2–12.4 GHz). Two different waveguide methods were used in the measurements. One technique utilized a finite sample and two reactive terminations, and the other required the use of an infinite sample simulated in the laboratory by a very long specimen. For each of the two Pittsburgh seam coal samples, dielectric constant and loss tangent variations were also measured as a function of moisture. Typical moisture contents of 10% and 15% were examined. Electromagnetic propagation through a single layer of coal seam was then investigated analytically as a function of coal depth.
15 citations
TL;DR: In this paper, the radiation coverage in the elevation plane on full scale Boeing 737 and Boeing 747 at 5.1 GHz, as applied to the microwave landing system (MLS), is examined for vertically and horizontally-polarized antennas mounted at different locations on the aircraft.
Abstract: Geometric optics and diffraction techniques are used to develop radiation models of antennas mounted on an aircraft structure. Measurements at 35 GHz on a 1/35 scale model space shuttle and 1/11 scale Boeing 737 are used for comparison with computed patterns and are in very good agreement. Radiation coverage in the elevation plane on full scale Boeing 737 and Boeing 747 at 5.1 GHz, as applied to the microwave landing system (MLS), is examined for vertically- and horizontally-polarized antennas mounted at different locations on the aircraft.
4 citations
01 Apr 1976
TL;DR: In this article, the elevation plane patterns of antennas mounted on different locations of an aircraft have been analyzed using diffraction techniques in conjunction with classical geometrical optics methods and compared with scaled-model measurements and are in very good agreement.
Abstract: Diffraction techniques in conjunction with classical geometrical optics methods have been used to analyse the elevation plane patterns of antennas mounted on different locations of an aircraft. The frame of the aircraft has been modelled using wedged and curved surfaces. Computed results have been compared with scaled-model measurements and are in very good agreement. Antenna locations examined are typical for communication and landing systems on an airframe.
2 citations