Abstract: An RF device includes a substrate and a series circuit of a tunable RF component and a DC blocking capacitor. The series circuit is arranged on the substrate and couples an RF signal terminal to a fixed voltage terminal that is electrically isolated from the RF signal terminal. The tunable RF component is coupled to the RF signal terminal, the DC blocking capacitor is coupled to the fixed voltage terminal and a driver terminal is coupled to the tunable RF component.

Abstract: A cheaper to produce, smaller and easy to drive adaptive antenna module is presented. The module comprises a signal path, an antenna, and a tuning circuit with two variable impedance elements. The tuning circuit operates over a restricted range of impedances and maintains the series resonance characteristic of the antenna.

Abstract: A communication system transmits signals having frequencies that lie within a transmission band and receives signals having frequencies that lie within a reception band. The system includes a duplexer and an antenna. The duplexer includes a transmission branch and a reception branch. The transmission branch includes a transmission filter, a transmission phase shifting network and a transmission matching network. The reception branch includes a reception filter, a reception phase shifting network and a reception matching network. The transmission matching network and the reception matching network have predominately constant phase shifts over frequencies within the reception band and within the transmission band, respectively. The antenna is coupled to the transmission matching network and to the reception matching network, and shows a predominantly reactance-only impedance variation over frequencies in the transmission band and over frequencies in the reception band.

Abstract: A terminal configured to receive data from a broadcast station that may simultaneously participate in a wireless network via transmissions to a wireless base station. The terminal determines time periods when data of interest to the terminal will be broadcast and schedules transmissions to the base station to avoid these time periods, thereby avoiding the transmissions preventing reception of the data of interest. The time periods may be determined amongst other means from scheduling information transmitted by the broadcast station.

Abstract: An RF device includes a substrate and a series circuit of a tunable RF component and a DC blocking capacitor. The series circuit is arranged on the substrate and couples an RF signal terminal to a fixed voltage terminal that is electrically isolated from the RF signal terminal. The tunable RF component is coupled to the RF signal terminal, the DC blocking capacitor is coupled to the fixed voltage terminal and a driver terminal is coupled to the tunable RF component.

Abstract: A cheaper to produce, smaller and easy to drive adaptive antenna module is presented. The module comprises a signal path, an antenna, and a tuning circuit with two variable impedance elements. The tuning circuit operates over a restricted range of impedances and maintains the series resonance characteristic of the antenna.

Abstract: A method of offsetting a mismatch due to user interaction when handling a portable wireless terminal in which antenna matching is changed from inductive matching to capacitive matching in response to a reactance change exceeding a threshold level and vice versa when an opposite change is detected. An antenna interface module (44) is coupled between a RF output or input stage (25 or 33) and an antenna (48 or 50). The antenna interface module includes first and second switches (SW1/1, SW1/2 or SW2/1, SW2/2), a first matching circuit including an inductive reactance (68 or 96) coupled between the power amplifier and the first switch and a second matching circuit including a capacitive reactance (68 or 92) is coupled between the RF output or input stage and the second switch (SW1/1 or SW2/1).

Abstract: A tuneable capacitor arrangement for RF use has two series coupled MEMS variable capacitors (C1,C2;C4,C5,C6,C7), varied according to a control signal. The series coupling enables the capacitor to withstand a higher voltage since this is shared by the individual capacitors in a series coupled arrangement. An increase in size of electrodes for each capacitor is compensated by a reduction in size of the springs supporting movable electrodes. These springs can have a larger stiffness value since the capacitance is larger. This means shorter springs, which can also result in a reduction in problems of stiction, resistance, and slow switching. The capacitances have a fixed and a movable electrode, with the RF signal coupled to the fixed electrode to avoid the springs needing to carry an RF signal. This can reduce the problems of inductance and resistance in the springs.

Abstract: A communication system transmits signals having frequencies that lie within a transmission band and receives signals having frequencies that lie within a reception band. The system includes a duplexer and an antenna. The duplexer includes a transmission branch and a reception branch. The transmission branch includes a transmission filter, a transmission phase shifting network and a transmission matching network. The reception branch includes a reception filter, a reception phase shifting network and a reception matching network. The transmission matching network and the reception matching network have predominately constant phase shifts over frequencies within the reception band and within the transmission band, respectively. The antenna is coupled to the transmission matching network and to the reception matching network, and shows a predominantly reactance-only impedance variation over frequencies in the transmission band and over frequencies in the reception band.

Abstract: A method of matching a receive-only antenna (60) for use in receiving video signals in which measurements made on a transceiver's antenna (14) when in an transmitting mode are used in matching the receive-only antenna. The ratio of the amplitude of the reflected signal to the strength of the transmitted signal strength is used not only in selecting components for matching the transceiver's antenna (14) but also in selecting components for matching the receive-only antenna (60). The ratio may be applied to respective look-up tables (54, 64) for selecting the components to be used in matching the respective antennas.

Abstract: A mobile telephone comprises a casing housing a telephone set to receive and transmit radiotelephone signals and a television set comprising a main television antenna (MAN) to receive radiotelevision signals, a television receiver arranged to process the received radiotelevision signals to output television signals to be displayed, and a display means display the outputted television signals. The main television antenna (MAN) is made in planar technology, is built-in inside the casing and comprises a filtering slot (FS) having chosen dimensions (D1, D2) to be resonant around the frequency of the radiotelephone signals to reject them at least partly.

Abstract: A wireless terminal includes a housing (10) containing a substrate (12) having a ground plane, RF components mounted on the substrate, a PIFA (Planar Inverted-F Antenna) (16) carried by the substrate and coupled electrically to the RF components for transmitting and receiving signals and a notch antenna (14) in the substrate for receiving signals in a frequency band at least partially overlapping the transmission bandwidth of some of the signals transmitted by the PIFA. The notch antenna is de-activated when the PIFA (16) is being used for transmitting a signal lying within the said transmission bandwidth.

Abstract: A communications apparatus, includes a housing (40) containing a printed circuit board (PCB) (12) having a ground plane (16) and electronic components in rf shields (18) thereon. A planar antenna (10) is mounted spaced from the ground plane and a dielectric (14) is present in a space between the PCB and the planar antenna. A feed (36) couples the planar antenna (10) to the rf components.

Abstract: A method of offsetting a mismatch due to user interaction when handling a portable wireless terminal in which antenna matching is changed from inductive matching to capacitive matching in response to a reactance change exceeding a threshold level and vice versa when an opposite change is detected. An antenna interface module (44) is coupled between a RF output or input stage (25 or 33) and an antenna (48 or 50). The antenna interface module includes first and second switches (SW1/1, SW1/2 or SW2/1, SW2/2), a first matching circuit including an inductive reactance (68 or 96) coupled between the power amplifier and the first switch and a second matching circuit including a capacitive reactance (68 or 92) is coupled between the RF output or input stage and the second switch (SW1/1 or SW2/1).

Abstract: A wireless terminal comprises a ground conductor (1102) and a transceiver coupled to an antenna feed, the antenna feed being coupled directly to the ground conductor (1102). In one embodiment the ground conductor is a conducting case (1102). The coupling may be via a parallel plate capacitor (504) formed by a plate (506) and a surface (1108) of the case (1102). The case (1102) acts as an efficient, wideband radiator, eliminating the need for a separate antenna. In a modification of this embodiment a slot (1112) is provided to increase the resistance of the case (1102) as seen by the transceiver, thereby increasing the radiating bandwidth of the terminal.

Abstract: A multi-band RF circuit has receive paths for two or more bands, and transmit paths, a bidirectional one-in multi-le-out transmission line junction (100) for combining the paths for coupling to an antenna. A switch combines transmit and receive paths, and a receive path circuit (110, 150, 160, 230, 240) is arranged to pass signals of its band, and appear open circuit to signals of the other bands. This means the combiner no longer needs to cut off the receive paths when they are not used. This can reduce components and thus reduce losses in the transmit paths for longer battery life or greater transmit range. A band filter (SAW) and a complementary circuit can achieve the open circuit. The bands can include GSM and GPS bands, the circuits can be used in tri band mobile handsets and handsets for future 3G bands, or base stations.

Abstract: A communications device, such as a cellular telephone, comprises a RF circuit and a PIFA antenna having feed and shorting terminations. An electrically conductive, self supporting member is provided to effect a connection between contact points of the RF circuit and the antenna. The member has at least one feed pillar and a shorting pillar which are substantially permanently connected to respective contact points of the RF circuit, and an antenna interface which forms a pressure connection with the terminations of the antenna.

Abstract: A tuneable capacitor arrangement for RF use has two series coupled MEMS variable capacitors (C1,C2;C4,C5,C6,C7), varied according to a control signal. The series coupling enables the capacitor to withstand a higher voltage since this is shared by the individual capacitors in a series coupled arrangement. An increase in size of electrodes for each capacitor is compensated by a reduction in size of the springs supporting movable electrodes. These springs can have a larger stiffness value since the capacitance is larger. This means shorter springs, which can also result in a reduction in problems of stiction, resistance, and slow switching. The capacitances have a fixed and a movable electrode, with the RF signal coupled to the fixed electrode to avoid the springs needing to carry an RF signal. This can reduce the problems of inductance and resistance in the springs.

Abstract: A multi-mode radio module (22) comprises a terminal (11) for connection to an antenna (10). A transmitting branch (DCS/PCS) and a branching circuit are coupled to the terminal (11). The branching circuit comprises at least a first and a second branch for receiving signals in first and second frequency bands (DCS, PCS), respectively. Each of the first and second branches comprise, respectively, a phase shifting circuit (PS1, PS2), a BAW or SAW band pass filter (RXF2, RXF3) coupled to the phase shifting circuit, the bandwidth of the filter being selected to pass a wanted signal in one of the first and second frequency bands but reject an unwanted signal in the other of the second and first frequency bands, and a low noise amplifier (LNA2, LNA3) coupled to an output of the band pass filter. The response of each of the band pass filters (RXF2, RXF3) is phase shifted to present an open circuit at the wanted frequency in the other branch.

Abstract: A wireless terminal a transceiver coupled to an antenna feed and a ground conductor (502), the antenna feed being coupled directly to the ground conductor (502). In one embodiment the ground conductor is a conducting case (902). The coupling is via a parallel plate capacitor formed by a respective plate (506) and a portion of the surface of the case (502). The case (502) acts as an efficient, wideband radiator, eliminating the need for separate antennas. Slots (912, 1214) perform a matching function, eliminating the need for matching between the transceiver and antenna feed.