Abstract: This invention relates to a tapered slot antenna with broadband characteristics whose beamwidth is stable over both the PCS (1850-1990 MHz) and the cellular bands (824-894 MHz). In a first preferred embodiment, a dual band antenna is disclosed which uses a single column elliptically shaped Vivaldi notches as the radiating elements. In a second preferred embodiment, a dual band antenna comprising elliptically shaped Vivaldi notches and sub-reflector positioned between a main reflector and the dipoles is disclosed. This resultant antenna produces a stable, ninety-degree beamwidth with a bandwidth broad enough to cover the PCS and the cellular bands.

Abstract: This invention relates to an improved coaxial cable preparation tool (1) that is used to prepare a coaxial cable terminal end for connector installation. The tool comprises two stages. The first stage, the jacket stripper, is used to trim the cable jacket. The second stage (20), the cable trimmer, is used to trim the remaining center, the outer conductors and the foam insulation of the coaxial cable. The first stage (10) consists of a cup or cylinder (11) with an outer cylindrical wall (12). In addition, it also comprises a blade (13) and a scrap port (14). In addition, the first stage cylinder (11) has a bore (16) extending axially down its center. The diameter of the bore (16) is set to receive a coaxial cable. The second stage consists of a hub (21) (or cutter head), a collet bearing (22) and a body (23). In addition, like the first stage, it also contains blades (13) and scrap ports (14). The scrap ports or debris ports (14) allow trimmed cable media to escape from the bores in the tool.

Abstract: An RF connector of a coaxial cable having an inner conductor, an outer conductor surrounding the inner conductor, a dielectric cylinder located between the inner and outer conductors, an outer radial barb projecting radially inwardly from the outer conductor into the cylinder, and an axial barb projecting axially from the outer conductor into the cylinder. The outer radial barb and axial barb work in cooperation to decrease the effect of contraction in the dielectric cylinder during colder temperatures, thereby providing a seal which prevents water and moisture from entering the connector.

Abstract: This invention relates to a one step coaxial connector for an annular corrugated coaxial cable. The components of the connector include an outer conductor clamping back nut, a collet and a body. The collet (1) enhances electrical performance by providing a full 360 degree contact with the outer conductor. In addition, an O-ring is used to provide a seal between the back nut and outer conductor of the cable. When the back nut (2) is screwed into the body (5), the collet (1) is forced further into the interior portion (11) of the connector body (5). The resilient fingers of the (1) collet are forced to close radially around the first corrugation groove (3) of the cable's outer conductor. In addition, an O ring (4), that initially resides in a cavity (12) created by the collet (1) and the back nut (2), is forced into a corrugation groove of the cable's outer conductor. A bore (6) on the back nut (2) provides the proper diameter to compress the O-ring (4) to provide a tight seal.

Abstract: The invention provides a power sharing amplifier system having an N by N transform matrix circuit, N amplifiers and an N by N inverse transform matrix circuit. The N by N transform matrix circuit has N input ports that respond to M input signals and provide N transform matrix input signals, where M is less than N. The N by N transform matrix circuit features at least one input port that does not receive an input signal but instead is coupled to ground. The N amplifiers respond to the transform matrix input signals and provide N amplified transform matrix input signals. The N by N inverse transform matrix circuit responds to the N amplified transform matrix input signals and provides N inverse transform matrix amplified output signals to output ports. Moreover, the N by N inverse transform matrix circuit features at least one output dissipation port that is coupled to ground to dissipate the intermodulation products contain thereon.

Abstract: A space-tapered antenna has a collinear array of radiating elements coupled via a cable feeding system to a Butler matrix feed system. Either the collinear array has compressed rows spaced in a range of ⅜ to ¼ &lgr;, where &lgr; is the operating wavelength of the antenna, the cable feeding system is a phase progression cable feeding system, or both. One 120° space-tapered antenna has eight compressed rows spaced at ⅜ &lgr; for providing six 20° degree beams with −10 dB side lobe suppression. Another 120° space-tapered antenna has eight compressed rows spaced at ¼ wavelength for providing four 30° beams with −15 dB side lobe suppression. A 60° space-tapered antenna has eight compressed rows spaced at ⅜ &lgr; in combination with a 22 ½° phase progression cable feeding system for providing three 20° beams with −14 dB side lobe suppression.

Abstract: An antenna arrangement is provide with a variable parasitic element whose position is varied as a function of the scan angle. According to an exemplary embodiment of the invention, a variable scanning array dual polarized antenna provides different scan angles by varying phase elements of the array. According to this embodiment an adjustable phase shift mechanism is used to modify the phase of the antenna array. The adjustable phase shift mechanism is used changes the antenna's phase as a function of a moveable dielectric slab. The dielectric slab slides over a microstrip line that results in a phase change that is a function of line coverage. A parasitic element is also connected to the dielectric slab such that the position of the parasitic element is varied in response to a change in the phase shift mechanism thereby varying the canceling signal of the parasitic element to optimize port isolation for the dual polarized antenna.

Abstract: A method and apparatus for calibrating an antenna apparatus and testing an antenna connected thereto is provided. The calibration is conducted without an antenna connected to establish a baseline return loss calibration coefficient. Thereafter, after an antenna is connected, a test may be conducted to measure the performance of the antenna on the antenna site apparatus. The calibration process includes measuring a leakage signal, measuring an average of the magnitude of a ripple output of the reflection signal over a frequency range to determine the baseline return loss calibration. Thereafter, if the antenna is connected and the test signal is again swept over frequency, then a new ripple factor is determined for the antenna and a new mean output voltage for Vant is determined. By comparing the new average output voltage for Vant and the baseline return loss calibration, one can determine information about the performance of the antenna.

Abstract: An apparatus for communicating, over a single transmission medium, two signals of substantially the same center frequency. The apparatus offsets in frequency one of the signals by combining the signal with the signal from a local oscillator. The apparatus then transmits the two signals, one offset from the other, as well as the signal from the local oscillator to allow for recovery of the two signals with a precise correction for the offset. In particular, the transmission medium is an optical fiber and the two signals are a main RF signal and a diversity RF signal received, respectively, by a main element and a diversity element of a diversity antenna system. The invention is of use, for example, in providing to a microbase station a main RF signal and its diversity RF signal received at a diversity antenna system remote from the microbase station and connected to the microbase station by an optical fiber.

Abstract: An improved log periodic dipole antenna, adapted for use in a cellular telephone system, has a plurality of radiating elements with differing lengths. The sequence of lengths selected results in a horizontal beam width of about 65 degrees and a front-to-back signal strength ratio exceeding 45 dB. This combination of characteristics reduces interference among adjacent cellular telephone transmitter sites, and reduces waste of transmission energy from the back of the antenna. A preferred sequence of radiating element lengths is long-short-long-short-long, which may be described as a “double stacked hourglass” configuration.

Abstract: An antenna control system is connected to an antenna in order to control the position of the antenna. The system includes a motor connected to the antenna for adjusting the position or vertical tilt angle of the antenna. A driver is provided for operating the motor. A sensor is also provided to detect the position of the antenna. In addition, an antenna controller is connected to an antenna memory, the driver, and the sensor, for reading the detected position of the antenna and for controlling the driver to adjust the antenna's position. A main controller is connected to the antenna controller for sending commands to and reading data from the antenna controller. In this manner, the main controller can interface with any number of antennas at a base station and control the position or down-tilt of each antenna. According to one embodiment of the control system, a user interface is also provided for entering commands to and reading data from the main controller.

Abstract: The invention provides a power sharing amplifier system for a cellular communications system, having with an 8th order transform matrix circuit, eight power sharing amplifiers and an 8th order inverse transform matrix circuit. The 8th order transform matrix circuit has six input ports and responds to six RF input signals for providing 8th order transform matrix RF input signals. The 8th order transform matrix circuit also has two input ports that do not receive input signals, but instead are coupled through a resistor to ground. The eight power sharing amplifiers respond to the 8th order transform matrix RF input signals, for providing eight amplified transformed RF signals. The 8th order inverse transform matrix circuit responds to the eight amplified transformed RF signals, for providing six inverse transform amplified RF output signals to six output ports.

Abstract: A microstrip antenna suitable for omnidirectional S-band operation is formed by the application of a plurality of microstrip radiating elements to the exterior surface of a dielectric tube. The microstrip radiating elements are fed by a branched microstrip input feed line connected to the elements. In the illustrated embodiment, the microstrip radiating elements are fed in-phase by feed line. A substantially cylindrical reflector tube is disposed within the dielectric tube.

Abstract: An isolation improvement circuit for a dual-polarization antenna, the dual-polarization antenna consisting of both a transmitter and receiver antenna for simultaneously transmitting a transmission signal and receiving a receiver signal, in which the transmitter and receiver antennas are configured so as to be mutually orthogonal either by physical or electrical orientation in order to reduce how much of the transmitter signal is picked up by the receiver antenna. The isolation improvement circuit reduces the level of transmitter signal appearing at the output port of the receiver antenna by providing a time-delayed transmission signal that destructively interferes with the transmitter signal picked up by the receiver element.

Abstract: The invention provides a log periodic dipole antenna having a microstrip center feedline and a log periodic hourglass dipole assembly. The microstrip center feedline means responds to an input radio signal for providing a microstrip center feed radio signal. The log periodic hourglass dipole assembly responds to the microstrip feed radio signal, for providing a log periodic hourglass dipole antenna radio signal.

Abstract: A coupling structure for coupling two resonant cavities, which may be dissimilar, based on providing a metallic surface, called here a guide surface, at an angle intermediate between the orientation of the magnetic field in the two cavities. The guide surface may be one surface of a non-rectangular window cut in a wall separating the two cavities or may be the surface of a coupling screw piercing, at the intermediate angle, a rectangular window in a wall between the two cavities. In the non-rectangular window embodiment, an adjusting tuning screw is provided that screws into a notch in the guide surface. In the angled coupling screw embodiment, coupling is adjusted by providing that more or less of the angled coupling screw extends into the rectangular window. The coupling structure couples any two cavities having mutually orthogonal magnetic fields by providing the guide surface at an orientation so the magnetic field in each cavity has a non-zero projection onto the guide surface.

Abstract: An antenna system producing a multi-beam antenna pattern having reduced sidelobe levels with a uniform beam pattern includes an antenna having a plurality of co-linear arrays of radiating elements including central co-linear arrays each of which has an identical number of radiating elements and a pair of outermost co-linear arrays each having a single radiating element. Each of the central co-linear arrays receives the full power output from a corresponding output of a Butler-matrix feed network except for two of the central radiating elements adjacent to the two outermost co-linear arrays, which each share the output power from a corresponding one of the outputs from the Butler-matrix feed network with one of the outermost co-linear arrays.

Abstract: The characterization and detection of an identifying bit sequence is performed without digital demodulation or bit synchronization. A waveform containing a digital bit sequence is correlated with waveforms corresponding to a set of known bit sequences. For each bit sequence, one of the inputs to a correlator is shifted through all possible values of correlation lag while the correlation match for each lag value is compared to the others so that a peak correlation between the two waveforms is determined. The peak correlation values for each of the known bit sequences are then compared to characterize how closely the received radio frequency signal corresponds to each of the known bit sequences. The bit sequence that most closely corresponds to the waveform of the received signal may then be identified. Applications include the identification of the N-AMPS DSAT and the GSM training sequence in a cellular radio scanning receiver.

Abstract: In a land mobile radio system including at least one base site having a system for interconnecting a plurality of radio channel units with a plurality of directional antennas and/or antenna beams, the base site further includes an interference avoidance system for controlling communications between each radio channel unit of the base site and mobile radio units communicating with the base site so as to avoid causing potential interference at the operating frequency of each radio channel unit at other base sites. The interference avoidance system monitors potential interference at the operating frequency of each radio channel unit on each antenna beam.

Abstract: A support system for an antenna having a pair of support arms (2) each secured at one end to a clamp (1) and having slots (3) formed at the other end to secure a support lug (4). The support lug has a first end (5) to receive a clamping mechanism (6) for securing the lug to a support pipe or column, and a second end (7) having at least three apertures (8,9) for attaching the lug to the support arms by means of fasteners (10). The slots in the support arms and support lug allow the support system to be secured to support pipes having a wide range of diameters by allowing each support arm to be secured to the support lug while forming any one of a range of angles therewith and while not requiring removal of the fastening bolts.