公开(公告)号：GB2347292A

公开(公告)日：2000-08-30

申请号：GB0003945

申请日：2000-02-18

Applicant: MOTOROLA INC

Inventor： PECKHAM DAVID SUTHERLAND ,  DING DAVID Z ,  SKUTTA FRANK ROBERT ,  JOHNSON JR ROBERT M

IPC: H03D7/12 ,  H04B1/40 ,  H04B1/26

Abstract: A multi-band receiver 102 has respective bandpass filters 306 and 304 for two closely spaced but distinct channels, e.g. 1.8 GHz DCS and 1.9 GHz PCS frequencies. A further bandpass filter 318 is coupled in series with a selected one of the filters 306 or 304, and has a passband which includes both reception bands. Sharing of the filter 318 between the two channels reduces cost and volume. The filter 318 may precede or follow the filters 306 and 304. A fourth filter 308 passes signals in a further band widely spaced from the other bands, e.g. a 900 MHz GSM band.

公开(公告)号：GB2301964B

公开(公告)日：2000-08-02

申请号：GB9611239

申请日：1996-05-30

Applicant: MOTOROLA INC

Inventor： PECKHAM DAVID SUTHERLAND ,  KIM JIN DONG ,  CRNKOVIC JAMES JOHN ,  KLOMSDORF ARMIN WERNER

IPC: H03F3/24 ,  H03F1/02 ,  H03F3/189 ,  H03G3/20 ,  H03G3/30 ,  H04B1/40

Abstract: A unique method and apparatus modifies the load impedance at the output of a power amplifier by varying a voltage variable capacitor (VVC) (310) to maximize the efficiency of the power amplifier (304). A comparator (509) generates amplifier control signal (211) based upon a detected power output signal (216) and a reference signal. In addition to providing power control, the control signal is also coupled to a VVC circuit (506) to control the output impedance of the power amplifier. In an alternate embodiment, a separate VVC control signal (527) based upon a comparison of the power control signal and the battery voltage is coupled to a VVC. In another alternate embodiment, a second VVC can be coupled in parallel to the first VVC. The second VVC is preferably controlled by a signal (805) based upon the current in the power amplifier. Finally, an alternate embodiment incorporates a VVC circuit (506) at the input of the power amplifier to compensate for variations in input impedance to improve other power amplifier parameters such as IM, gain, output power and noise level.

公开(公告)号：DE19806096C2

公开(公告)日：2000-05-11

申请号：DE19806096

申请日：1998-02-14

Applicant: MOTOROLA INC

Inventor： VLAHOS CONSTANTINE ,  PECKHAM DAVID SUTHERLAND ,  SKUTTA FRANK ROBERT

IPC: H04B1/40 ,  H03D7/12 ,  H03J1/00 ,  H04B1/26 ,  H04B1/44 ,  H04L27/00 ,  H04B1/06 ,  H04B1/16 ,  H04B7/005 ,  H04L27/38

Abstract: A method and apparatus enables a communication device (100) to operate in multiple bands, such as GSM 900 MHz, DCS 1800 MHz, and DCS 1900 MHz bands, by eliminating the need for a mixer for each band. In a dual band GSM/DCS 1800 radiotelephone, for example, the local oscillator (LO) injection frequencies for both GSM and DCS bands are provided to a mixer (234) through the use of combination filters (222, 246). Thus, the duplexing and matching requirements to the mixer input are simplified and the signal losses are minimized. The common output ports of the GSM RX/LO combination filter and DCS RX/LO combination filter are duplexed to the input of the mixer. Also, the input impedance matching of the mixer is designed to match the impedance for the received signals in each band, as well as provide an RF trap at the IF frequency. The match at the output of the mixer is designed to match the impedance of the IF filter and provides a low impedance to RF input frequencies. Finally, a tri-band radiotelephone is also described.

公开(公告)号：DE19806097A1

公开(公告)日：1998-08-20

申请号：DE19806097

申请日：1998-02-14

Applicant: MOTOROLA INC

Inventor： PECKHAM DAVID SUTHERLAND

IPC: H03L7/099 ,  H03B1/00 ,  H03B5/18 ,  H04B1/40 ,  H03B5/38 ,  H04B1/04

Abstract: The voltage controlled oscillator (VCO) includes a transistor (302) with a base, a collector and an emitter, for generating an oscillating output signal. A first coil (302) and capacitor are connected to the transistor base. A first control node receives a band selection voltage which switches a second capacitor to the base and emitter to change the output signal band. A second control node receives the band selection signal and switches a third capacitor (322) to the emitter to alter the oscillating output signal. There may be a second capacitor (310) connected in parallel with the first capacitor.

公开(公告)号：BR9602624A

公开(公告)日：1998-04-22

申请号：BR9602624

申请日：1996-06-04

Applicant: MOTOROLA INC

Inventor： CRNKOVIC JAMES JOHN ,  KLOMSDORF ARMIN WERNER ,  KIM JIN DONG ,  PECKHAM DAVID SUTHERLAND

IPC: H03F3/24 ,  H03F1/02 ,  H03F3/189 ,  H03G3/20 ,  H03G3/30 ,  H04B1/40 ,  H04Q7/32

Abstract: A unique method and apparatus modifies the load impedance at the output of a power amplifier by varying a voltage variable capacitor (VVC) (310) to maximize the efficiency of the power amplifier (304). A comparator (509) generates amplifier control signal (211) based upon a detected power output signal (216) and a reference signal. In addition to providing power control, the control signal is also coupled to a VVC circuit (506) to control the output impedance of the power amplifier. In an alternate embodiment, a separate VVC control signal (527) based upon a comparison of the power control signal and the battery voltage is coupled to a VVC. In another alternate embodiment, a second VVC can be coupled in parallel to the first VVC. The second VVC is preferably controlled by a signal (805) based upon the current in the power amplifier. Finally, an alternate embodiment incorporates a VVC circuit (506) at the input of the power amplifier to compensate for variations in input impedance to improve other power amplifier parameters such as IM, gain, output power and noise level.

公开(公告)号：ZA964876B

公开(公告)日：1997-01-07

申请号：ZA964876

申请日：1996-06-07

Applicant: MOTOROLA INC

Inventor： KIM JIN DONG ,  CMKOVIC JAMES JOHN ,  KLOMSDORF ARMIN WERNER ,  PECKHAM DAVID SUTHERLAND

IPC: H03F3/24 ,  H03F1/02 ,  H03F3/189 ,  H03G3/20 ,  H03G3/30 ,  H04B1/40 ,  H03F ,  H03G

Abstract: A unique method and apparatus modifies the load impedance at the output of a power amplifier by varying a voltage variable capacitor (VVC) (310) to maximize the efficiency of the power amplifier (304). A comparator (509) generates amplifier control signal (211) based upon a detected power output signal (216) and a reference signal. In addition to providing power control, the control signal is also coupled to a VVC circuit (506) to control the output impedance of the power amplifier. In an alternate embodiment, a separate VVC control signal (527) based upon a comparison of the power control signal and the battery voltage is coupled to a VVC. In another alternate embodiment, a second VVC can be coupled in parallel to the first VVC. The second VVC is preferably controlled by a signal (805) based upon the current in the power amplifier. Finally, an alternate embodiment incorporates a VVC circuit (506) at the input of the power amplifier to compensate for variations in input impedance to improve other power amplifier parameters such as IM, gain, output power and noise level.