Abstract: The invention specifies a tunable RF filter which may operate using electroacoustic components and provides good electrical properties despite having a wide tuning range. For this purpose, the RF filter comprises a tunable filter core (AFK) having electroacoustic (EAK) and detunable (AKE) filter elements, and impedance restoration circuits (IWS1, IWS2) for compensating for an impedance change by tuning the filter core.

Abstract: The present invention concerns a mobile communication device comprising a ground plane, a main antenna comprising a main radiator (MRAD) that can couple electromagnetically to the ground plane and to a first signal path (SPm), a diversity antenna comprising a diversity radiator (DRAD), a reconfigurable input matching circuit that couples the diversity radiator (DRAD) to the ground plane and to a second signal path (SPd), and a control unit (CU) coupled to the reconfigurable input matching circuit and adapted to change the coupling of the diversity radiator (DRAD) to the ground plane during operation. The present invention further concerns to a method to enhance the performance of the device.

Abstract: A circuit arrangement includes an antenna port, a first receiving port, a second receiving port, a first transmission port, and a second transmission port. A number of 90 degree hybrids are configured to transfer an input signal into two output signals that are phase shifted relative to each other. Two quadplexers each include a first duplexer and a second duplexer. The quadplexers and the 90 degree hybrids are interconnected such that a leakage signal travelling from one of the transmission ports to one of the receiving ports destructively interferes at the receiving port.

Abstract: A circuit arrangement includes an antenna port, a transmission port, and a reception port, each of which is connected to one respective 90° hybrid that splits an input signal into two output signals that are in quadrature. The circuit arrangement also includes two duplexers which are connected in such a way that the two output signals emitted by the 90° hybrid that is connected to the transmission port constructively interfere on the antenna port, while spurious signals caused by the two output signals destructively interfere on the reception port.

Abstract: A circuit arrangement includes an antenna port, a transmission port, and a reception port, each of which is connected to one respective 90° hybrid that splits an input signal into two output signals that are in quadrature. The circuit arrangement also includes two duplexers which are connected in such a way that the two output signals emitted by the 90° hybrid that is connected to the transmission port constructively interfere on the antenna port, while spurious signals caused by the two output signals destructively interfere on the reception port.

Abstract: A wireless communication device (WCD) having improved tuning abilities is provided. The device comprises an absorption element (AE) connected to an additional antenna (MIMOA). RF power coupled from a main antenna (MA) into the additional antenna (MIMOA) is absorbed instead of being re-emitted into the main antenna (MA) and disturbing measurement of the reflected power level.

Abstract: The present invention concerns a front-end circuit (FEC) that is connectable to at least two radiators (RAD1M, RAD1D), wherein the front-end circuit (FEC) comprises sub-circuits (SC) and each sub-circuit (SC) is associated to one radiator (RAD1M, RAD1D). Further, each sub-circuit (SC) comprises a signal path (SP), an antenna port (AP) that is electrically coupled to the signal path (SP) and connectable to the radiator (RAD1M, RAD1D), a grounding port (GP) that is connectable to the radiator (RAD1M, RAD1D), a ground termination circuit (GTC), and a grounding switch (GS) that is electrically coupled to the grounding port (GP) and to the grounding termination circuit (GTC).

Abstract: Mobile communication devices with improved antenna performance are provided. A mobile communication device includes a first antenna, a ground plane, and a diversity antenna. In a mode of operation which is not a multi-antenna transmission mode, the diversity antenna is electrically coupled to the ground plane. The diversity antenna increases the electrical length of the ground plane and enhances the antenna performance of the radiating assembly of the first antenna in combination with the ground antenna and the diversity antenna.

Abstract: A wireless communication device (WCD) having improved tuning abilities is provided. The device comprises an absorption element (AE) connected to an additional antenna (MIMOA). RF power coupled from a main antenna (MA) into the additional antenna (MIMOA) is absorbed instead of being re-emitted into the main antenna (MA) and disturbing measurement of the reflected power level.

Abstract: A front-end circuit for a wireless communication unit includes at least two antenna feeds. At least one of the antennas is coupled to an antenna switch. The circuit comprises filters and duplexers and is prepared to operate a number of FDD frequency bands. Each FDD band comprises an Rx band for receive signals and a Tx band for transmit signals. The circuit provides a single band operation mode for each frequency band and aggregated band operation modes. In an aggregated band operation mode Rx signals can be received in two different frequency bands at the same time as well as Tx signals can be transmitted in at least one of the two different frequency bands. In addition, TDD bands as well as GSM bands are covered.

Abstract: The present invention concerns a mobile communication device comprising a ground plane, a main antenna comprising a main radiator (MRAD) that can couple electromagnetically to the ground plane and to a first signal path (SPm), a diversity antenna comprising a diversity radiator (DRAD), a reconfigurable input matching circuit that couples the diversity radiator (DRAD) to the ground plane and to a second signal path (SPd), and a control unit (CU) coupled to the reconfigurable input matching circuit and adapted to change the coupling of the diversity radiator (DRAD) to the ground plane during operation. The present invention further concerns to a method to enhance the performance of the device.

Abstract: The present invention concerns a front-end circuit (FEC) that is connectable to at least two radiators (RAD1M, RAD1D), wherein the front-end circuit (FEC) comprises sub-circuits (SC) and each sub-circuit (SC) is associated to one radiator (RAD1M, RAD1D). Further, each sub-circuit (SC) comprises a signal path (SP), an antenna port (AP) that is electrically coupled to the signal path (SP) and connectable to the radiator (RAD1M, RAD1D), a grounding port (GP) that is connectable to the radiator (RAD1M, RAD1D), a ground termination circuit (GTC), and a grounding switch (GS) that is electrically coupled to the grounding port (GP) and to the grounding termination circuit (GTC).

Abstract: A circuit arrangement includes an antenna port, a transmission port, and a reception port, each of which is connected to one respective 20° hybrid that splits an input signal into two output signals that are in quadrature. The circuit arrangement also includes two duplexers which are connected in such a way that the two output signals emitted by the 20° hybrid that is connected to the transmission port constructively interfere on the antenna port, while spurious signals caused by the two output signals destructively interfere on the reception port.

Abstract: Mobile communication devices with improved antenna performance are provided. A mobile communication device includes a first antenna, a ground plane, and a diversity antenna. In a mode of operation which is not a multi-antenna transmission mode, the diversity antenna is electrically coupled to the ground plane. The diversity antenna increases the electrical length of the ground plane and enhances the antenna performance of the radiating assembly of the first antenna in combination with the ground antenna and the diversity antenna.

Abstract: An antenna arrangement including: a coupling element, a conductive element; an extension element for electrically extending the conductive element and a reactive element. A method of creating an antenna arrangement including an antenna element having a first resonant frequency and a first bandwidth, a conductive element, an extension element, for electrically extending the conductive element, having a size and an inductor having an inductance value wherein the extended conductive element has a resonant mode having a second resonant frequency and a second bandwidth, the method including: selecting the size of the extension element, the inductance value and a position of the inductor to tune the resonant mode of the extended conductive element so that the second bandwidth in the region of the first resonant frequency is larger than the first bandwidth in the region of the first resonant frequency.

Abstract: An antenna arrangement including: a coupling element, a conductive element; an extension element for electrically extending the conductive element and a reactive element. A method of creating an antenna arrangement including an antenna element having a first resonant frequency and a first bandwidth, a conductive element, an extension element, for electrically extending the conductive element, having a size and an inductor 40 having an inductance value wherein the extended conductive element has a resonant mode having a second resonant frequency and a second bandwidth, the method including: selecting the size of the extension element, the inductance value and a position of the inductor to tune the resonant mode of the extended conductive element so that the second bandwidth in the region of the first resonant frequency is larger than the first bandwidth in the region of the first resonant frequency.

Abstract: A transceiver front-end having a plurality of signal paths operatively connected to at least two electrically separated antennas for transmitting and receiving communication signals in a plurality of frequency bands in GSM and W-CDMA modes. If the frequency band of one signal path is partially overlapping with the frequency band of another signal path, these two signal paths are connected to two different antennas. As such, some of the switching components and matching elements in the transceiver front-end can be eliminated. As a result, the reception loss can be reduced.

Abstract: In an RF front-end having a plurality of signal paths connectable to an internal antenna or an external antenna, an antenna switch part is used to select either the internal or the external antenna. In the antenna switch part, two series switches are used to operatively connect to the same connection point in each signal path. These two series switches are separately connected to two different antennas for selecting one of the antennas in order to route the signals in that signal path. For providing further isolation between signal paths, each signal path can be connected to a shunt switch near the connection point. Only the shunt switch connected to the selected signal path is operated in an open position, all the other shunt switches are operated in a closed position.

Abstract: A transceiver system having an RF front-end operatively connected to two separate non-50 ohm antennas for separately providing transmission/reception paths for 1 GHz band and for 2 GHz band. A switching module is operatively connected to each antenna for mode and frequency-range selection within each band. Each switching module has a plurality of switching elements connected to a plurality of signal paths. Matching is separately and independently provided for each signal path. The matching can be achieved by using distributed elements or lumped elements arranged in shunt or series in order to widen the bandwidth. An electrostatic discharge protection circuit is provided between the antenna feed point and the switching module. The protective circuit can also be used as a discrete matching network that can be optimized depending on the phone mechanics and dimensions.

Abstract: A dual-channel passband filtering system having a first, second and third balanced ports for connecting, respectively, to a first transceiver, an antenna and a second transceiver. A first lattice-type passband filter is connected between the first and the second port, and a second lattice-type passband filter is connected between the second and the third port. A phase shifter is used to match the first and second transceiver and the second port. A balun can be used for each port to convert the balanced port to a single-ended port. In each passband filter, two series resonators are use to provide two balanced ends, and two shunt resonators are connected to the series resonators in a crisscross fashion to form a differential or balanced topology. The first and second passband filters have different frequencies.