Abstract: An antenna system capable of receiving electromagnetic radiation having either right or left helical polarization, and either vertical or horizontal linear polarization includes an energy concentrator which concentrates energy at a focal point. A helical antenna is arranged in the proximity of the focal point. A first switch switches the helical antenna to a backfire mode of operation and a second switch switches the helical antenna to an end fire mode of operation. A control mechanism controls the switches to select the nature of the polarization.

Abstract: A unitary hand-held bar code scanner and reader produces an elliptical beam, oriented with its major axis along the direction of the bars, utilizing optics employing far field diffraction effects to shape the beam and maintain its elliptical aspect (length to width ratio) constant over a distance in front of the scanner were bar codes may be located. The optics eliminates parallax even though the photodetector and light source (preferably a laser diode) are located offset from each other on a board on which the optics are mounted. A housing assembly has channels which mount the board therein without shock absorbing devices. A digital microcomputer controller and peripheral devices regulate the optical power output from the laser diode and prevents catastrophic failure, if the electrical current through the laser diode exceeds safe limits.

Abstract: A microstrip array antenna for vertically polarized fan beam (approximately 2.degree..times.50.degree.) for C-band SAR applications with a physical area of 1.7 m by 0.17 m comprises two rows of patch elements and employs a parallel feed to left- and right-half sections of the rows. Each section is divided into two segments that are fed in parallel with the elements in each segment fed in series through matched transmission lines for high efficiency. The inboard section has half the number of patch elements of the outboard section, and the outboard sections, which have tapered distribution with identical transmission line sections, terminated with half wavelength long open-circuit stubs so that the remaining energy is reflected and radiated in phase. The elements of the two inboard segments of the two left- and right-half sections are provided with tapered transmission lines from element to element for uniform power distribution over the central third of the entire array antenna.

Abstract: A slot fed antenna is disclosed for use in radiating energy. The antenna includes a flat conductive member having an elongated vertically-oriented slot dividing the member into a pair of horizontally-extending variable-length flat dipole wing elements. Each of the flat dipole wing elements has a vertically-extending rectilinear edge. Also, each wing element extends in width in a direction perpendicular to the rectilinear edge from a minimum at its center and at each of its upper and lower ends to a maximum midway between each of the ends and the center.

Abstract: Synthesizer radiating systems providing efficient wideband operation incorporate a radiating element (20a), such as a loop, dipole or whip, which has dimensions which are small relative to wavelength in the radiated frequency band. Energy dissipation is substantially reduced by cycling stored energy back and forth between a radiating element (20a) having a first reactance and a storage element (22a) having the same or opposite reactance, in order to achieve energy efficiency along the lines of a narrowband tuned-circuit antenna. Wideband operation is achieved by synthesizing a representation of an input waveform (at 28) by actively controlling (30) solid-state switching devices (24), responsive to rate control and direction control parameters, which are interactive with the energy transferred between the opposite reactances. Higher efficiencies are achieved by bipolar circuits providing separate positive and negative energy transfer paths between a radiating element and a storage element.

Abstract: The present invention relates to a micro-wave plate antenna, especially for Doppler radar for example, of the type with a Janus configuration, made up of a plurality of linear sub-networks parallel among themselves, or of a single linear sub-network, each sub-network being made up of a plurality of radiating elements placed on each side of a sub-network feed line, the sub-networks being fed in phase, the length of the sub-network feed line is, between two neighboring elements, a whole multiple of the length of the wave guided over the substratum of the printed circuit on which are printed the radiating elements, and that corresponds to the operational frequency of the antenna.