公开(公告)号：CA2204377A1

公开(公告)日：1997-03-20

申请号：CA2204377

申请日：1996-09-11

Applicant: QUALCOMM INC

Inventor： KORNFELD RICHARD K ,  WEILAND ANA L ,  PITTA THOMAS A ,  PETERZELL PAUL E ,  WALLACE RAYMOND C

IPC: H01P1/213 ,  H03H7/46 ,  H04B1/40

Abstract: A dual-band antenna system for use in a portable communications device is disclosed herein. The antenna system includes an antenna element (10) for radiating electromagnetic energy within low-band and high-band wavelength ranges. In a preferred embodiment, a low-band isolator network (20), coupled to the antenna element (10), provides signal isolation between high-band and low-band signal paths during high-band operation. Similarly, a high-band isolator network (18) provides signal isolation, during operation over the lowband range of wavelengths, between the high-band and low-band signal paths. During transmit and receive operation, low-band and high-band electromagnetic energy directed through the antenna (10) is passed by the low-band and highband isolator networks, (20) and (18) respectively. Also included are low-band and high-band matching networks (28) and (36), respectively, which couple the low-band and high-band isolator networks (20) and (18), respectively, to lowband and high-band transceiver circuitry.

公开(公告)号：ZA9607264B

公开(公告)日：1997-03-04

申请号：ZA9607264

申请日：1996-08-27

Applicant: QUALCOMM INC

Inventor： PITTA THOMAS A ,  PETERZELL PAUL E ,  KORNFELD RICHARD K ,  WEILAND ANA L ,  WALLACE RAYMOND C

IPC: H01P1/213 ,  H03H7/46 ,  H04B1/40 ,  H01Q ,  H04B

CPC classification number: H04B1/406 ,  H01P1/213 ,  H03H2007/386 ,  H04B1/005 ,  H04B1/18

公开(公告)号：FI964345A

公开(公告)日：1996-10-28

申请号：FI964345

申请日：1996-10-28

Applicant: QUALCOMM INC

Inventor： PETERZELL PAUL E ,  WILSON NATHANIEL B ,  BLACK PETER J

IPC: H03G3/20 ,  H03G3/30 ,  H04B1/16 ,  H04B1/18 ,  H04L27/22 ,  H04L27/38 ,  H03G

Abstract: An automatic gain control (AGC) apparatus for a digital receiver is disclosed herein. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. The AGC apparatus further includes a measurement circuit for generating a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and generates an gain control signal in response to a result of the comparison. The saturating integrator includes a decision circuit for enabling integration based on values of the received power signal, the reference signal, and the gain control signal. In a preferred implementation the utilization of an input limiter in conjunction with an analog to digital converter enables accommodation of an increased input signal dynamic range. Accordingly, the AGC apparatus is capable of being used in digital demodulation of FM signals. The AGC apparatus may also be employed within a dual mode receiver designed to process both FM and code division multiple access (CDMA) input signals.

公开(公告)号：CA2467276A1

公开(公告)日：1996-06-20

申请号：CA2467276

申请日：1995-12-11

Applicant: QUALCOMM INC

Inventor： WEILAND ANA L ,  KORNFELD RICHARD K ,  WHEATLEY CHARLES E III ,  PETERZELL PAUL E

IPC: H04B1/06 ,  H03G1/00 ,  H03G3/30 ,  H04B20060101 ,  H04B1/10 ,  H04B1/16 ,  H04B1/18 ,  H04B1/40 ,  H04B1/7075 ,  H04B1/7097 ,  H04B3/06 ,  H04B7/005 ,  H04B7/26 ,  H04B15/00

Abstract: An apparatus to increase a radio receiver's immunity to radio frequency interference, the radio receiver receiving a signal, the apparatus comprising: a switch (1105) coupled to the received signal, the switch (1105) having an open position and a closed position; a resistance (1101), a first end of the resistance (1101) being coupled to the closed position of the switch (1105) and a second end of the resistance (1101) being coupled to a ground potential; an amplifier (1101) having an input coupled to the open position of the switch (1105), for generating an amplified received signal at an output; a controller coupled to the switch (1105), for switching the switch (1105) to the closed position in response to the received signal exceeding a predetermined power level, said received signal conducting through said switch (1105) and said resistance (1101) to ground potential when said switch (1105) is in said closed position; and said resistance (1101) creating an impedance mismatch at the input to said amplifier (1110) when said switch (1105) is in closed position, thereby reducing the gain contributed by said amplifier (1110).

公开(公告)号：CA2207745A1

公开(公告)日：1996-06-20

申请号：CA2207745

申请日：1995-12-11

Applicant: QUALCOMM INC

Inventor： KORNFELD RICHARD K ,  WEILAND ANA L ,  WHEATLEY CHARLES E III ,  PETERZELL PAUL E

IPC: H04B1/06 ,  H03G1/00 ,  H03G3/30 ,  H04B20060101 ,  H04B1/10 ,  H04B1/16 ,  H04B1/18 ,  H04B1/40 ,  H04B1/7075 ,  H04B1/7097 ,  H04B3/06 ,  H04B7/005 ,  H04B7/26 ,  H04B15/00 ,  H04Q7/32

Abstract: The method and apparatus of the present invention improve the immunity to interference of a radio receiver. The power level of a received signal is detected. If the power level meets or exceeds a predetermined power threshold, the low noise amplifier (703) is by-passed (730), thus increasing the intercept point of the receiver components. Alternative embodiments include the use of an RF power detector (105) to control the front-end gain (110) as a function of jammer power. In lieu of a switchable RF gain block (730), several methods of continuous gain control are proposed. Continuous gain control allows the interference suppression and sensitivity of the receiver to be adjusted at lower signal levels than the switchable gain block. A method of the present invention adjusts the input gain by a predetermined amount (1601). The receiver processing measures the gain change in the IF signal power (1605). If the change is less than the predetermined amount (1610), the CDMA signal and jammers are below the noise floor and, therefore, the gain is increased (1615). If the IF signal power change is greater than the predetermined amount, the interference is evident and the gain is reduced to reduce the intermodulation products (1620). This process is used until the receiver is operating at the best compromise between interference and noise figure.

公开(公告)号：FI956286A

公开(公告)日：1996-02-26

申请号：FI956286

申请日：1995-12-27

Applicant: QUALCOMM INC

Inventor： WILSON NATHANIEL B ,  BLACK PETER J ,  PETERZELL PAUL E

IPC: H03D3/00 ,  H03G3/20 ,  H03D3/24 ,  H03D7/16 ,  H03G3/30 ,  H04B1/30 ,  H04L27/14 ,  H04L27/22 ,  H04B

Abstract: An automatic gain control (AGC) and D.C. offset correction method and apparatus for controlling signal power of a received RF signal within a dual mode quadrature receiver is disclosed herein. In a preferred implementation the automatic gain control apparatus may be adjusted to provide a desired control response to various fading characteristics of a received FM, FSK, GMSK, QPSK, or BPSK signal. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. A quadrature downconverter coupled to the output port serves to translate the frequency of the output signal to a baseband frequency, thereby producing baseband signals. In a preferred implementation the downconverter is operative to map the carrier frequency of the output signal to a baseband frequency offset by a predetermined margin from D.C. Two high gain active lowpass filters provide out-of-band signal rejection for the baseband signals. A D.C. feedthrough suppression loop, disposed to receive said baseband signal, suppresses D.C. offsets produced by the downconverter and lowpass filters, hence providing a compensated baseband signal. The AGC apparatus is further disposed to generate a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and produces the gain control signal by integrating or by refraining from integration based on values of the reference, received power signal, and gain control signals, thereby extending the usable dynamic range of the receiver for FM mode.

公开(公告)号：AU2398695A

公开(公告)日：1995-11-29

申请号：AU2398695

申请日：1995-04-28

Applicant: QUALCOMM INC

Inventor： PETERZELL PAUL E ,  WILSON NATHANIEL B ,  BLACK PETER J

IPC: H03G3/20 ,  H03G3/30 ,  H04B1/16 ,  H04B1/18 ,  H04L27/22 ,  H04L27/38

Abstract: An automatic gain control (AGC) apparatus for a digital receiver is disclosed herein. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. The AGC apparatus further includes a measurement circuit for generating a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and generates an gain control signal in response to a result of the comparison. The saturating integrator includes a decision circuit for enabling integration based on values of the received power signal, the reference signal, and the gain control signal. In a preferred implementation the utilization of an input limiter in conjunction with an analog to digital converter enables accommodation of an increased input signal dynamic range. Accordingly, the AGC apparatus is capable of being used in digital demodulation of FM signals. The AGC apparatus may also be employed within a dual mode receiver designed to process both FM and code division multiple access (CDMA) input signals.