Abstract: A balanced antenna system for a communication device includes a balanced transmission line electromagnetically coupled to a transceiver of the device. A symmetrical dipole antenna element is operable at a first frequency driven by the balanced transmission line. A symmetrical loop antenna shares portions of the dipole antenna element and is operable at a second frequency driven by the transmission line. Preferably, the antenna system is disposed within a flip portion of the device housing.

Abstract: An improved antenna system to channel counterpoise currents for an unbalanced antenna such as a helical monopole. A first conductor, or ground resonator, is coupled to a ground connection near the antenna and is located distally from a user to reduce electromagnetic exposure. The first conductor presents a low impedance path at an operating frequency of the antenna such that RF currents are attracted onto the first conductor. A second conductor, such as a printed circuit board or user interface circuitry, is also coupled to the ground connection of the first conductor. The second conductor presents a high impedance path at the operating frequency of the antenna such that RF currents are diverted away from the second conductor which is held closer to a user than the first conductor.

Abstract: A difference drive diversity antenna structure (200) and method for a portable wireless communication device (230) aligns a first linear antenna (240) parallel to a major axis (245) of the communication device and drives dual radiators (252, 254) of a second antenna (250) at equal magnitudes but with a 180 degree phase difference. A difference drive diversity antenna structure implemented in a portable wireless communication device maintains significant decorrelation between the first antenna (240) and the second antenna (250) over the common frequency ranges of the dual radiators (252, 254). Also, antenna currents on the body of the communication device are minimized and the effects of a hand or body near the communication device are reduced.

Abstract: A difference drive diversity antenna structure (200) and method for a portable wireless communication device (230) aligns a first linear antenna (240) parallel to a major axis (245) of the communication device and drives dual radiators (252, 254) of a second antenna (250) at equal magnitudes but with a 180 degree phase difference. A difference drive diversity antenna structure implemented in a portable wireless communication device maintains significant decorrelation between the first antenna (240) and the second antenna (250) over the common frequency ranges of the dual radiators (252, 254). Also, antenna currents on the body of the communication device are minimized and the effects of a hand or body near the communication device are reduced.

Abstract: A first coil (110) resonant at a first frequency, and a second coil (120) resonant at a second frequency, coupled to a conductive straight portion (140) of an antenna element (130) to form a multi-band antenna structure. The first and second coils (110) and (120) are preferably of different axial lengths and circumferences, wound in opposite directions and coaxially disposed about the antenna element (130). Additional coils can be added to accommodate additional bands and an upper coils (150) can be used to realize a multi-position structure.

Abstract: Multiple helical coils (110, 120, 130) are placed side-by-side and coupled to a conductive straight portion (140) of an antenna to provide a multi-band antenna structure. The helical coils (110, 120, 130) are distanced from one another to sufficiently eliminate coupling interference therebetween. A portable radio capable of communication in many different frequency bands utilizing a single, compact antenna structure is thus realized.

Abstract: The integrated shielding and mechanical support simultaneously addresses the problems of providing RF shielding for an electronic device such as a radio transceiver and providing a rigid mechanical assembly for the electronic device. Two conductive rails (120, 130) hold together multiple printed circuit boards (PCBs) (140, 160) having conductive layers (145, 165) to produce a four-sided shielding box (180) that protects certain electronic circuits on the PCBs from electromagnetic interference. An internal conductive shield (150) subdivides the inside of the shielding box to provide additional protection for sensitive circuitry. The shielding box inserts into an opening in a five-sided housing section (110) using guides (112, 114, 116, 118), which simplifies assembly of PCBs in the housing and facilitates automated assembly. A second housing section (190) attaches to the shielding box (180) once it is inserted into the five-sided housing section (110).

Abstract: A transformation network is provided capable of interfacing between an unbalanced port (110) and a plurality of differently phased balanced ports (120, 130). A balun (165) has a choke (140) and connects the unbalanced port (110) to a balanced pair of nodes. An additional node (145) is provided on the balun. First and second unbalanced phase shift transmission lines (150, 155) have a common ground conductor connected to the additional node (145) of the balun (165). A phase-shifted balanced port (130) is thus provided by center conductors of these first and second unbalanced phase shift transmission lines (150, 155) when the other ends of these transmission lines are coupled to the balanced nodes of the balun (165) and the common ground conductor of these transmission lines is connected to the additional node (145) of the balun.

Abstract: A multi-position antenna apparatus is provided for a device including a first housing portion and a second housing portion which are interconnected such that they move relative to one another between a collapsed position and an extended position. The device includes radio circuitry positioned in the first housing portion. The antenna apparatus includes a first antenna supported in the second housing portion. The first antenna is coupled to the radio circuitry in the extended position and in the collapsed position. A parasitic radiator is supported in the first housing portion and is only coupled to the first antenna when the housing is in the collapsed position. The parasitic radiator is a quarter wavelength of the signaling frequency or an integer multiple thereof. The parasitic radiator may include a member inductively or capacitively coupled to the first antenna when the flap is closed. Alternatively, the parasitic radiator may be a patch radiator or a loop conductor.

Abstract: An electrical connection between a balanced circuit, such as a radio receiver and an unbalanced circuit, such as an antenna requires a balun. In a small electronic device such as a radiotelephone, a traditional balun is impractical because of the physical constraints. The balun function is performed by using a transmission line of minimum transverse dimensions and a predetermined length between the receiver and the antenna.

Abstract: An antenna system includes a first antenna positioned on a first device housing and a parasitic radiator positioned on a second device housing. The housings move relative to one another to collapse the device during a standby mode and extend the device during an active communication mode. The first antenna and the parasitic radiator are positioned on their respective housings such that they are parasitically coupled when the housings are collapsed and are not coupled when the housings are extended.

Abstract: A radio communication device includes a radio signal source (415) positioned in the first housing portion (101). A second housing portion (103) has a first end movably supported on the first housing portion such that the housing portions are reconfigurable between an extended position and a collapsed position. A dipole antenna (107) has a first arm (440) positioned in the first housing portion and a second arm (441) positioned in the second housing portion. A respective end of each of the arms is connected to the signal source. Plates (450, 451) are positioned on the first and second housing portions and connected to the antenna arms such that they are capacitively coupled when the housing portions are collapsed and are not coupled when the housing portions are extended.

Abstract: An earth station transceiver (210) is provided for communicating with at least one satellite (110, 120) in orbit. The earth station transceiver (210) has an antenna with an array of antenna elements (220, 230) and steering circuitry (240) for steering an antenna pattern created by the array of antenna elements. A position of a beam (310-330) from a satellite can be represented by a beam number. The antenna pattern can be determined without taking signal quality measurements when the beam is at an extreme elevation angle as represented by the beam number. Signal quality measurements can alternatively be made during a time slot or frame to choose an antenna pattern instead of choosing an antenna pattern based on satellite beam number when the beam is not at an extreme elevation angle. Signal quality measurements using the same antenna pattern are made to perform an intra-site handoff. Signal quality measurements using all antenna patterns are made to perform an intersite handoff.

Abstract: When a radio frequency (RF) circuit is integrated into a movable housing element of an electronic device one must consider the affects of the surrounding area when the RF circuit is in a functioning position. A preferred embodiment is a radiotelephone (100) having an antenna (105) integrated into a movable housing element (101). The antenna (105) has two functioning positions, an opened and a closed position. The antenna (105) is tuned for efficiency when the movable housing element (101) is in the opened position. When the movable housing element (101) is in the closed position, a first pair of conductive plates (107, 109) located in the movable housing element (101) and a second conductive plate (113) located in the second housing element (103) are positioned to retune the antenna (105) due to the detuning affects caused by the close proximity of other electronic components located in the second housing element (103).

Abstract: A transmission line has a limited cross-section, a transmission line geometry and an improved characteristic impedance tolerance. The transmission line geometry utilizes a unique combination of broadside coupling and coplanar coupling with a reflector plate in order to improve the tolerance of the characteristic impedance. First, a larger coplanar gap is used to reduce the etching error. Second, the inner dielectric thickness sensitivities were also reduced by relying on broadside coupling and coplanar coupling to determine the characteristic impedance of the transmission line. Third, the effect of registration error in the broadside coupling is eliminated by rendering the two signal bearing conductors on the same layer.

Abstract: An antenna for an electronic apparatus is located in a flip element of the apparatus housing. A transformer, having a winding in the flip element and a winding in the housing couples electromagnetic energy across the hinge while impedance matching and performing a balun function.

Abstract: A diversity antenna structure and a diversity transceiver incorporating the same. Each antenna of the diversity antenna structure is formed of a first portion and a second portion. Second portions of each antenna are coupled to an electrical ground plane and form thereby ground plane portions of the respective antennas. Such second antenna portions are maintained in physical isolation from one another thereby, when receiving high frequency signals, to be maintained in apparent electrical isolation from one another. Because such ground plane portions are maintained in the apparent electrical isolation from one another, antennas of the diversity antenna structure may be positioned in close proximity to one another without causing coupling between the separate antennas of the diversity antenna structure.

Abstract: The antenna coupling apparatus of the present invention couples an antenna, located in a hinged element (102) of a wireless communication device, to the receiver (401) of the device. In the preferred embodiment, the communication device is a radiotelephone. The coupling is achieved without contact or flexible cable by parallel plate capacitors (201 and 202) in the hinge of the communication device. The capacitors (201 and 202) additionally act as a matching network for the antenna.

Abstract: A rotatable contactless RF signal coupler, which couples RF signals between an antenna and an RF signal processor in a portable radio, along with an antenna capable of operating in two modes is described herein. Specifically, the signal coupler includes a transformer that is primarily located within the hinge formed by the housing of the radio and a rotatable flip portion. Substantially constant inductive coupling is maintained in the coupler regardless of rotation. The antenna is capable of operating in a narrow band and a wide band mode to afford antenna operation through varied conditions.

Abstract: A metal shield is dimensioned to enclose a portion of a portable radio having an internal antenna and a first transmission line. A transmission line mounted in the shield is positioned to be adjacent to the first transmission line when the shield engages the radio and permits energy to be coupled between the resonator and the first transmission line. The first transmission line and the shield are dimensioned so that the electrical length of the first transmission line increases to 2L when the shield engages the radio, where L is the electrical length of the first transmission line when the shield does not engage the radio. This electrical length transformation by an integral multiple of one half wavelength helps to maintain the input impedance to the internal antenna.