Abstract: A wireless telephone (102) includes a telephone transceiver (104), GPS receiver (106), and Bluetooth transceiver (108). The telephone antenna (110) is external, and the Bluetooth antenna (120) is internal. The GPS receiver (106) may be driven by its own internal antenna (326), or via a signal separator (116), (216), by either of the other antennas ((110), (120).

Abstract: Provided is a system and method for eliminating the effects of antenna coupling by increasing the isolation between closely mounted antennas on a portable wireless communications device. Increased isolation is achieved by providing a ceramic resonator in the path of each of the antennas. The ceramic resonator placed in the path of a particular antenna eliminates the effects of coupling caused by a particular one of the other antennas by rejecting signals associated with the particular antenna.

Abstract: A diplexer for providing an efficient, low cost, passive, reliable system and method for sharing a single antenna between a cellular subsystem and a GPS subsystem. The inventive diplexer includes first and second devices coupled to an input node for receiving a composite signal having first and second component signals at first and second frequencies respectively. In accordance with the invention, the first device passes the first signal and provides an open circuit to the second signal, while the second device passes the second signal and provides an open circuit to the first signal. In the illustrative embodiment, the first and second devices are first and second transmission lines respectively. The transmission lines may be of any type, i.e., microstrip, stripline, coplanar waveguide etc.

Abstract: A dual-band octafilar helix antenna operational at two frequencies, while maintaining a relatively small package size. The dual-band octafilar antenna is manufactured by disposing radiators and a feed network onto a flexible substrate and forming the substrate into a cylindrical shape to obtain the helical configuration. The dual-band octafilar helix antenna includes four active radiators which are matched to a first frequency and disposed on a radiator portion of the flexible substrate. Four additional radiators, which may be either passive or active radiators, are matched to a second frequency, are also disposed on the radiator portion of the substrate and interleaved with the active radiators. At least one feed network is provided on a feed portion of the substrate that provides 0.degree., 90.degree., 180.degree., and 270.degree. signals to active radiators.

Abstract: A quadrifilar antenna is comprised of four radiators which, in the preferred embodiment, are etched onto a radiator portion of a microstrip substrate. The microstrip substrate is formed into a cylindrical shape such that the radiators are helically wound. Also etched onto the microstrip substrate is a feed network that provides 0.degree., 90.degree., 180.degree. and 270.degree. signals to the antenna radiators. The feed network utilizes a combination of one or more branch line couplers and one or more power dividers to accept an input signal from a transmitter and to provide therefrom the 0.degree., 90.degree., 180.degree. and 270.degree. signals needed to drive the antenna. For receive operations, the feed network utilizes these same components to receive the 0.degree., 90.degree., 180.degree. and 270.degree. signals from the antenna radiators and to provide a single output signal to a communications receiver.

Abstract: A 180.degree. power divider accepts an input signal and splits it into two output signals that are equal in amplitude and differ in phase by 180.degree.. In a first region, an unbalanced input signal travels along a trace on a circuit surface of a substrate. On the opposite surface is a ground plane. In a second region, the ground plane tapers to a width that is substantially equal to the width of the signal trace. As a result, opposite the signal trace is a return signal trace of substantially the same width. In this region, the signal is a balanced signal, and for the current flowing in the signal trace, there is an equal but opposite current flowing in the return signal trace on the opposite side. In a third region, the return signal trace is brought to the circuit surface of the substrate and a second ground plane is provided on the opposite surface. This second ground plane is floating with respect to the first ground plane. The return signal differs in phase from the other signal by 180.degree..

Abstract: A coaxial-waveguide assemblage is disclosed herein of the invention includes a first coaxial transmission line having a first inner and a first outer conductor. The inventive assemblage further includes a waveguide electromagnetically coupled to the first coaxial transmission line, where an inner surface of the waveguide bounds a signal propagation space. The waveguide is also electromagnetically coupled to a second coaxial transmission having a second inner and a second outer conductor. The inner conductor of the second coaxial transmission line is disposed to rotate about a first vertical axis, thereby enabling the second coaxial transmission line to be connected to a rotating antenna. In a particular implementation the coaxial-waveguide assemblage is disposed within a rotary joint operative to couple electromagnetic energy between first and second signal ports.