Abstract: A low visibility, field-diverse antenna provides cross-polarized fields enhancing signal communications. A generally flat, but helical, antenna is achieved in conjunction with a core substrate about which the antenna is wrapped, wound, or fixed. The core substrate, pitch or angle of the helix, and length of the transmitting antenna are chosen for a specific resonant frequency. The length and width of the helix are chosen in order to dimension the helical antenna between its linear and circular polarization modes to thereby deliver field-diverse and cross-polarized transmission modes. In order to optimize the manufacturing process, holes may be created within the substrate. These holes are plated with conducting material so that conducting foil on opposite faces of the substrate may be electrically connected. The holes may be offset according to the pitch of the helix.

Abstract: A low-profile antenna has increased broad-banding capacities as well as a lower radiation angle for enhanced cellular or mobile telephone wireless transmissions. Enhancing a basic PIFA antenna, a top metal radiator is notched so as to provide additional corners and greater perimeter length thereby enhancing the bandwidth capabilities of the antenna. Both ground and tuning tabs serve to enhance operational characteristics and a dielectric cover incorporating prismatic qualities serves to lower the radiation angle of transmission from approximately forty degrees (40.degree.) to twenty degrees (20.degree.). The prisms provide an operating radiation angle in the range of approximately seventy degrees (70.degree.) to twenty degrees (20.degree.).

Abstract: A low visibility, field-diverse antenna provides cross-polarized fields enhancing signal communications. A generally flat, but helical, antenna is achieved in conjunction with a core substrate about which the antenna is wrapped, wound, or fixed. The core substrate, pitch or angle of the helix, and length of the transmitting antenna are chosen for a specific resonant frequency. The length and width of the helix are chosen in order to dimension the helical antenna between its linear and circular polarization modes to thereby deliver field-diverse and cross-polarized transmission modes. In order to optimize the manufacturing process, holes may be created within the substrate. These holes are plated with conducting material so that conducting foil on opposite faces of the substrate may be electrically connected. The holes may be offset according to the pitch of the helix.

Abstract: A base station antenna includes a matching network that broadbands transmission without requiring adjustment. Using a one-quarter wavelength (1/4 .lambda.) or less sperrtopf sleeve in a coaxial arrangement, broadbanding is achieved by adding a second conductor parallel to the transmission line center conductor. A ring inductor is tapped at one end off-center by the second conductor. The inductor's step-up end is connected to the antenna with the primary end connected to the transmission line center conductor. Mutual inductance may be present, but is not required, between the transmission line center and second conductors. Fringing capacitance between the antenna and the sleeve establishes an "L" network in conjunction with the inductor. To protect the inductor from the elements, it is placed inside the antenna near the sleeve.

Abstract: A wide-banded mobile antenna enhancing signal transmission by broadening the effective transmission bandwidth. The wide-banded mobile antenna is interchangeable with currently existing mobile antennas as the two use connectors established by industry. An antenna matching network is situated within a protective housing having a metal shield. A toroidal inductor is serially connected with the antenna and creates a parasitic capacitance with the metal shield. The resulting network, including the antenna, is tuned. An antenna compensating network increases the bandwidth of the antenna with a parallel resonance network. The parallel resonance network has a capacitor and an inductor connected in parallel to the antenna and each other. The parallel resonance inductor is oriented so that the fields it generates are perpendicular to those of the antenna and the matching inductor to prevent coupling between the inductors.

Abstract: A low cost and portable scalar network analyzer for the simultaneous measurement of forward and reflected scalar scattering parameters of devices under test. Plural UHF oscillators of similar construction are mixed to produce a wideband test instrument having good stability characteristics. A dual-diode biased RF detector with feedback, including an in-loop adjustable gain buffer stage, provides enhanced linearity, over a wide dynamic range, and at low cost. The forward transfer parameter measurement arrangement further includes a selectable attenuation/gain PIN-diode switched stage to accommodate the widely varying gain/attenuation characteristics of devices under test.