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    An efficient class B RF amplifier with supply voltage modulation
    3.
    发明专利
    An efficient class B RF amplifier with supply voltage modulation 未知

    公开(公告)号：GB2425418A

    公开(公告)日：2006-10-25

    申请号：GB0508049

    申请日：2005-04-22

    Applicant: MOTOROLA INC

    Inventor： FRIEDLANDER HAIM ,  SHIRAZI GADI

    IPC: H03F1/02

    Abstract: The dc collector or drain current of class B amplifying transistor 101 is detected by a sense resistor 108 and differential amplifier 112. The output voltage Vcc of the switching regulator 107 is controlled to be in proportion to the sensed current so that the amplifier operates slightly below saturation at all input power levels. In a class B amplifier, the DC supply current is proportional to the output RF power level. The amplifier may be used in mobile or base stations. The technique avoids the effect of transistor variations with time or variations between devices. There is no need to calculate the power envelope from in-phase and quadrature data and there is no need to compensate for inherent delays to achieve matching of the supply voltage and the RF power envelope.

    Circuits for use in radio communications
    4.
    发明专利
    Circuits for use in radio communications 未知

    公开(公告)号：GB2413444A

    公开(公告)日：2005-10-26

    申请号：GB0408831

    申请日：2004-04-21

    Applicant: MOTOROLA INC

    Inventor： LUZZATTO ARIEL ,  FRIEDLANDER HAIM ,  SHIRAZI GADI

    IPC: H03L7/087 ,  H03L7/113 ,  H03L7/18 ,  H03L7/185 ,  H03L7/20

    Abstract: A frequency synthesiser circuit for use in wireless communications including a phase locked loop including a VCO (voltage controlled oscillator), wherein the synthesiser circuit includes a further oscillator which in operation is a free running oscillator at a frequency higher than the VCO and a mixer connected to receive input signals from the VCO and from the further oscillator and to combine such signals. Also described is a wireless communications transmitter or receiver incorporating the frequency synthesiser circuit.

    Circuit board having first and second inductors mounted on either side of the board
    5.
    发明专利
    Circuit board having first and second inductors mounted on either side of the board 未知

    公开(公告)号：GB2404091A

    公开(公告)日：2005-01-19

    申请号：GB0316573

    申请日：2003-07-15

    Applicant: MOTOROLA INC

    Inventor： FRIEDLANDER HAIM ,  BASRI ELIYAHU ,  SHIRAZI GADI

    IPC: H01F17/02 ,  H05K1/02 ,  H05K1/18

    Abstract: A circuit board construction 15 comprises a first inductor 13 electrically connected to a second inductor 14, where the first inductor is located on a first surface of the circuit board and the second inductor is located on the other surface of the circuit board. When each inductor has the same inductance, this construction allows the total inductance of the two inductors to remain constant during any deformation of the circuit board as the increase in inductance of one of the inductors as it contracts 19, cancels out the decrease in the inductance of the other, as it expands 17. The circuit board may be used in a voltage controlled oscillator (VCO) circuit in, for example, a mobile telephone. The inductors may be air core coiled inductors and the axes of the coils of the first and second inductors may be parallel to each other.

    Antenna diversity arrangement for an rf transceiver
    6.
    发明专利
    Antenna diversity arrangement for an rf transceiver 未知

    公开(公告)号：GB2428917A

    公开(公告)日：2007-02-07

    申请号：GB0516057

    申请日：2005-08-04

    Applicant: MOTOROLA INC

    Inventor： FRIEDLANDER HAIM ,  BASRI ELIYAHU ,  SHIRAZI GADI

    IPC: H04B1/44 ,  H04B1/48 ,  H04B7/06 ,  H04B7/08

    Abstract: An antenna switching arrangement is disclosed for an rf transceiver which may operate at 2.4GHz or 5GHz. It has been recognised that antenna diversity, if required, is needed only in the receive mode and not in the transmit mode. The resulting circuit comprises a first antenna 113 connected to the common terminal (pole) of a first spdt switch 209, a second antenna 115 connected to the common terminal of a second spdt switch 213, the first and second switches being connected to respective transmitters 101 and 103. The first and second switches are connected to a third spdt switch 211 which in turn connects the antennas to a common receiver 105. This circuit connects each transmitter to its respective antenna through a path which includes only one transmit-receive switch, and thus reduces transmit power losses in comparison to prior art arrangements (fig. 1) in which the transmitter signal must pass through more than one switch.

    A transmitter splits a signal into a plurality of sub-signals, each containing a plurality of sub-carriers, and amplifies each sub-signal separately.
    7.
    发明专利
    A transmitter splits a signal into a plurality of sub-signals, each containing a plurality of sub-carriers, and amplifies each sub-signal separately. 未知

    公开(公告)号：GB2428168A

    公开(公告)日：2007-01-17

    申请号：GB0513752

    申请日：2005-07-06

    Applicant: MOTOROLA INC

    Inventor： SHIRAZI GADI ,  FRIEDLANDER HAIM ,  LUZZATTO ARIEL ,  SERAFY SALOMON

    IPC: H04L27/26

    Abstract: An RF transmitter (200) including means (201) for generating a multi-carrier modulation signal comprising a plurality of sub-carriers, means (309 fig 3) for modulating an RF carrier signal (c(t)) with the sub-carriers of the multi-carrier modulation signal to produce a modulated signal, a signal splitter (305 fig 3) to split a signal including the sub-carriers of the multi-carrier modulation signal into a plurality of sub-signals each including a sub-set of the plurality of sub-carriers, a plurality of power amplifiers (203) each operable to amplify a separate one of the sub-signals to produce an amplified sub-signal and an RF power combiner (205) operable to combine the amplified sub-signals for transmission as a combined amplified RF signal. The invention may be used for OFDM transmission. It reduces the peak-to-average power ratio (PAPR).

    Circuit for control of receiver dynamic range in order to save battery current
    10.
    发明专利
    Circuit for control of receiver dynamic range in order to save battery current 未知

    公开(公告)号：GB2381415A

    公开(公告)日：2003-04-30

    申请号：GB0125463

    申请日：2001-10-24

    Applicant: MOTOROLA INC

    Inventor： SHIRAZI GADI ,  FRIEDLANDER HAIM

    IPC: H04B1/10 ,  H04B1/16 ,  H04B1/06

    Abstract: A receiver circuit for use in a wireless communication unit (100) includes signal measurement means (112, 270, 280) for measuring a wideband signal strength of a received radio frequency signal. The receiver also includes a signal processor (225) operably coupled to the signal measurement means (112, 270, 280) for determining whether a dynamic range performance of the receiver should be adapted based on the measured wideband signal strength. A radio frequency amplifier (220), has a current level controlled (290) by a control signal produced by the signal processor (225), wherein the signal processor (225) controls the current consumption of the radio frequency amplifier (220) to set a dynamic range performance of the receiver. The receiver circuit provides the advantage that the necessary dynamic range is determined in an adaptive, real-time manner so as to save battery current.

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