Abstract: An antenna comprising: first and second dielectric layers; a conductive slot layer disposed between the first and second dielectric layers, wherein the slot layer has a slot therein with short and long axes of symmetry; a pair of arcs, rotated 180° from each other, made of conductive material, and disposed on top of the first dielectric layer, wherein proximal ends of the arcs are vertically-aligned with the short axis of symmetry and equidistant from the long axis of symmetry and electrically connected to the slot layer through vias in the first dielectric layer; and a forked feed made of conductive material disposed on the bottom of the second dielectric layer, wherein the forked feed has a centerline that is vertically-aligned with the short axis of symmetry.

Abstract: An antenna comprising: first and second dielectric layers; a conductive slot layer disposed between the first and second dielectric layers, wherein the slot layer has a slot therein with short and long axes of symmetry; a pair of arcs, rotated 180° from each other, made of conductive material, and disposed on top of the first dielectric layer, wherein proximal ends of the arcs are vertically-aligned with the short axis of symmetry and equidistant from the long axis of symmetry and electrically connected to the slot layer through vias in the first dielectric layer; and a forked feed made of conductive material disposed on the bottom of the second dielectric layer, wherein the forked feed has a centerline that is vertically-aligned with the short axis of symmetry.

Abstract: A dual feed slot antenna can include a ground plane formed with an aperture, and first feed and second feeds extending into the aperture. The first feed and second feed can extend into the aperture so that the first feed and second feed are coincident and out of phase with other. The first feed and said second feed can define a U-shaped stub, with a respective stub length, a stub width, a crossbar and a pair of stub tines defining a stub separation extending from the crossbar. The first feed and second feed can extend into the aperture so that each of the stub tines from a first feed are coincident the stub tines from the second feed. With this configuration, and with further selection of the said respective stub lengths, stub widths and stub separations, a symmetric omnidirectional radiation can be established for the antenna.

Abstract: A ferrite-loaded broadband loop antenna having nearly comparable transmit/receive characteristics is disclosed. The antenna contains a low loss ferrite core having a width-to-height ratio of approximately 24 and a depth-to-height ratio of approximately 6, and an antenna feed plate assembly centered about the long axis of the ferrite core, having a width-to-height ratio of approximately 6 and a width-to-depth ratio of approximately 1, and a balanced feed located at the center of the antenna feed plate assembly, positioned on the radiating side of the antenna, and a low loss center element in the ferrite core, the center element having at least one of a loss tangent and a permeability that is lower than the ferrite core, and a grounding surface coupled to the antenna feed plates.

Abstract: A method for making transmission measurements in a dual-chambered anechoic chamber used in conjunction with spatial averaging. At selected transmitter antenna positions, measurement are taken at different frequencies. For each transmitter position, a measurement is made with the test device positioned between the apertures, and another without the test device. When all desired measurements have been made, the measurement data are spatially averaged; i.e., the measurements are scaled, summed, and averaged, providing more accurate transmission measurements.

Abstract: A dual-chambered anechoic chamber used in conjunction with spatial averaging for making transmission measurements of electromagnetic devices. The anechoic chamber includes a first tapered chamber with a first aperture, a second tapered chamber with a second aperture opposed to the first aperture, an alignment apparatus for aligning the two chambers and, if necessary, for positioning a test device between the apertures, and a positioning mechanism for mounting and determining the position of a transmitter antenna. A receiver antenna in the second chamber receives test signals transmitted from the transmitter antenna. At selected transmitter antenna positions, measurements are taken at different frequencies. For each transmitter position, a measurement is made with the test device positioned between the apertures, and another without the test device. When all desired measurements have been made, the measurement data are spatially averaged; i.e.