Abstract:
An antenna diversity system includes at least two antennas. Each antenna may be connected via a common connection point to a receiver by a respective switch which presents a low impedance connection between the antenna and receiver in the on state and a substantially reactive load to the antenna in the off state. Selection of appropriate impedances for the off state load enables the antennas to function as an array with a variety of beam patterns depending on the state of the switches. Cycling through a sequence of switch states steers the antenna beam providing improved resistance to fading and multipath effects. Alternatively, the antennas may be connected to a hybrid coupler, which enables two beam patterns to be available simultaneously for signal quality measurement and comparison.
Abstract:
An antenna arrangement comprises a patch conductor (102) supported substantially parallel to a ground plane (104) and a feed conductor (106) connected to the patch conductor. Such an arrangement is similar to a conventional Planar Inverted-F Antenna (PIFA), but lacks the additional grounding conductor connected between the patch conductor and the ground plane in known PIFAs. Elimination off this grounding conductor enables matching to be performed by external circuitry, thereby enabling a better match to be achieved and enabling similar performance to conventional PIFA antennas to be achieved from a reduced volume. These advantages are particularly apparent for dual-band (or multi-band) operation, where the use of a dual-band matching circuit allows a much smaller end less complex antenna to be used.
Abstract:
An antenna arrangement comprises a folded structure (100) comprising first and second sections (102, 104) defining a transmission line. The sections may be meander-line elements or other physically-shortened electric elements, for example a helical element. Respective feed points (103, 105) are provided at the free ends of the sections (102, 104), thereby enabling independent connections to be made for different modes, such as transmit and receive. Top-loading and additional short-circuit elements may be provided to improve performance and reduce antenna volume. The impedances of the sections (102, 104) may be arranged to differ by adjusting conductor width or by fabricating one of the sections as a plurality of conductors connected in parallel. Discrete components may be included within the antenna structure, to provide enhanced design possibilities, while multi-band operation is enabled by fabrication of additional folded structures within the same volume.
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:
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 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 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. Each of the phase shifting circuits (PS1, PS2) is impedance transforming so that higher impedance filters can be used.
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.
Abstract:
An antenna diversity arrangement is applicable to frequency hopping receiver (34) for receiving data packets transmitted on frequency channels lying within an overall frequency bandwidth, divided into a plurality of sub-bands. In each sub-band the frequency characteristics of the channel will be substantially the same. The choice of antenna (10, 12) for a particular sub-band is done by carrying-out frequency diversity measurements and the selection is treated as being valid for a period of time which may be preset or determined dynamically. In operation the hopping sequence is known to the receiver so that it can determine in advance the frequency of the next data packet to be received and can select the particular antenna without the necessity of carrying out diversity measurements. At the end of the time period the suitability of the selected antenna is checked and if necessary the selection is updated in the receiver.
Abstract:
An antenna arrangement comprises a patch conductor (102) supported substantially parallel to a ground plane (104), a feed pin (106) connected to the patch conductor at a first point and a ground pin (108) connected between a second point on the patch conductor and the ground plane. The feed and ground pins are connected by a linking conductor (510) and have shunt capacitance means coupled across them. Suitable values of the capacitance means and the location and dimensions of the linking conductor enable a good match to the antenna to be achieved. The linking conductor may be directly connected to the patch conductor or there may be gaps between the feed and ground pins both above and is below the linking conductor. An impedance transformation may be provided by the feed and ground pins having different cross-sectional areas and/or by the provision of a slot in the patch conductor.