摘要:
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 (12, 13) as the radiating elements. In a second preferred embodiment, a dual band antenna comprising elliptically shaped Vivaldi notches (12, 13) 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.
摘要:
A tower top amplifier for use outdoors in a radio frequency communications system has a surge suppression device for suppressing electrical surges caused by lightning strikes. The surge suppression circuit has a short circuit inductive coupling loop connected to a coaxial cable connector (102). By using a capacitor (110) connected in parallel with an inductive probe (114), the surge suppression circuit operates as an open circuit at the operating frequency of the system. In addition, at the operating frequency, the resistor (112) matches the impedance of the system connected to the coaxial cable connector (102). But in the event of a lightning strike or other electrical event, the inductive coupling loop short circuits the surge current to ground, thereby protecting the amplifier system from damage.
摘要:
An angle diversity antenna system utilizes a first antenna, a second antenna, and a panel combiner coupled to the first and second antenna. In a transmit mode, the first and second antenna are coupled to a transmit sum channel of the panel combiner. In a receive mode, either the sum channel or a difference channel of the panel combiner is chosen as the active channel. By monitoring the sum channel and difference channel, the antenna system according to the present invention is able to select the channel which supplies the greatest signal strength.
摘要:
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 (10), 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.
摘要:
A system for inductively cross coupling resonators. Two resonators are interconnected by a cross coupler with the two ends, each end having a hole. The holes secures each end of the cross coupler to one of the resonators. The use of a stamped piece as a cross coupler results in a repeatable placement between resonators that minimizes any variation in coupling between resonators due to human error during assembly. This repeatability reduces assembly time and assembly cost.
摘要:
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. The time delay is provided by sizing a conductor used to convey the transmission signal to the output port of the receiver antenna, or to the receiver antenna and then to the output port, the sizing including not only selecting a length of the conductor, but also, optionally and depending on the type of conductor, adjusting any capacitive or inductive elements of the conductor.
摘要:
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 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.
摘要:
An antenna control system is connected to an antenna (10) in order to control the position of the antenna. The system includes a motor (20) 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 (30) is also provided to detect the position of the antenna. In addition, an antenna controller (40) 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 (50) 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 (60) is also provided for entering commands to and reading data from the main controller. The interface can be provided at the base station or tower or at a remote location via, for example, modem. According to one embodiment of the invention the user interface is a laptop computer. A user or technician can then enter commands and monitor the position of the antennas from a remote location.