公开(公告)号：AT415736T

公开(公告)日：2008-12-15

申请号：AT00976898

申请日：2000-11-03

Applicant: QUALCOMM INC

Inventor： WALKER BRETT ,  SAHOTA KAMAL

IPC: H03G3/30 ,  H03G3/10 ,  H04B1/04

Abstract: Techniques for adjusting the bias current of an active circuit in a transmitter based on the signal gain of the transmitter. The bias current affects various performances including linearity, noise figure, frequency response, and others. The amount of bias current that provides the required level of performance is dependent on the power level, which can be inferred from the gain control signals used to control the variable gain elements in the transmit signal path. Initially, at least one gain control signal for at least one variable gain element in the transmit signal path is received, with each gain control signal being indicative of an amplitude of a signal to be operated on by the active circuit. The bias current of the active circuit is then adjusted in accordance with the received gain control signal(s). To ensure proper circuit performance, the bias current can be limited to within a range defined by an upper value Imax and a lower value Imin can be set to a percentage of Imax. Imax and Imin can be generated by programmable current sources, and can also be compensated for temperature and power supply variations.

公开(公告)号：ES2364630T3

公开(公告)日：2011-09-08

申请号：ES02709570

申请日：2002-02-15

Applicant: QUALCOMM INC

Inventor： LI TAO ,  HOLENSTEIN CHRISTIAN ,  KANG INJUP ,  WALKER BRETT ,  PETERZELL PAUL ,  CHALLA RAGHU ,  SEVERSON MATTHEW ,  RAGHUPATHY ARUN ,  SIH GILBERT C

IPC: H03G3/30 ,  H03D3/00 ,  H04B1/40

Abstract: Un procedimiento de operación de un bucle de CC en una unidad receptora que comprende: seleccionar un modo operativo particular para el bucle de CC entre una pluralidad de posibles modos operativos que incluyen un modo de adquisición; y, si el modo operativo seleccionado es el modo de adquisición, operar el bucle de CC en el modo de adquisición en una duración temporal particular para corregir una desviación de CC en una señal deseada, en el que la duración temporal particular es inversamente proporcional a un ancho de banda del bucle para el bucle de CC para el modo de adquisición, y salir del modo de adquisición después de la duración temporal particular.

公开(公告)号：AT402522T

公开(公告)日：2008-08-15

申请号：AT01979671

申请日：2001-10-09

Applicant: QUALCOMM INC

Inventor： WALKER BRETT ,  ZEISEL ERIC ,  SAHOTA GURKANWAL

IPC: H03G7/00 ,  H03G7/06 ,  G06G7/24 ,  H03G3/10 ,  H03G3/30 ,  H03G7/08

Abstract: Techniques to linearly (in dB) adjust the gains of variable gain elements (i.e., variable gain amplifiers or VGAs) in a receiver or transmitter. An input control signal is provided to a conditioning circuit that conditions the control signal to achieve various signal characteristics. The input control signal is limited to within a particular range of values, temperature compensated, scaled (or normalized) to the supply voltages, shifted with an offset, or manipulated in other fashions. The conditioned signal is then provided to an input stage of a linearizer that generates a set of exponentially related signals. This is achieved using, for example, a differential amplifier in which the conditioned control signal is applied to the inputs of the differential amplifier and the collector currents from the differential amplifier comprises the exponentially related signals. An output stage within the linearizer receives the exponentially related signals and, in response, generates a gain control signal. By approximately matching the output stage to a gain stage of the variable gain element and by using the gain control signal generated by output stage, the gain transfer function of the VGA approximates that of the exponentially related signals.

公开(公告)号：AT510351T

公开(公告)日：2011-06-15

申请号：AT02709570

申请日：2002-02-15

Applicant: QUALCOMM INC

Inventor： LI TAO ,  HOLENSTEIN CHRISTIAN ,  KANG INJUP ,  WALKER BRETT ,  PETERZELL PAUL ,  CHALLA RAGHU ,  SEVERSON MATTHEW ,  RAGHUPATHY ARUN ,  SIH GILBERT C

IPC: H03G1/00 ,  H03G3/30 ,  H03D3/00 ,  H03G3/20 ,  H04B1/40 ,  H04L27/22 ,  H04L27/38

Abstract: An apparatus and method in a wireless communication system, the apparatus comprising: first means for amplifying a received signal; means for cancelling a DC offset in the amplified signal; second means for digitally amplifying the DC offset cancelled signal; and means for measuring the digitally amplified signal and to control the gains of the first and second amplifying means.

公开(公告)号：AT376720T

公开(公告)日：2007-11-15

申请号：AT00976924

申请日：2000-11-03

Applicant: QUALCOMM INC

Inventor： GARD KEVIN ,  SAHOTA KAMAL ,  WALKER BRETT

IPC: H04B1/16 ,  H04L27/20 ,  H04B1/04 ,  H04B1/06 ,  H04L27/22

Abstract: A device for use in a wireless communications system that reduces the amount of phase noise in the carrier signals due to powering down circuit elements for reducing power consumption. The device includes one or more carrier signal generators coupled to a transmitter. Each signal generator provides a respective carrier signal. The transmitter receives and modulates one or more carrier signals with one or more input signals to generate a modulated signal, which is gated on and off during a discontinnous data transmission. The transmitter includes one or more input buffers, with each input buffer receiving and buffering a respective carrier signal. The input buffers are maintained biased for the duration of the data transmission, even as the modulated signal is gated on and off, to provide a constant load for the signal generators and to isolate the carrier signal generators from switching noise. Some other active elements in the transmitter may be powered down when the modulated signal is gated off to further reduce power consumption.