Apparatus for mobile communication system which performs signal transmission by amplitude modulation and phase modulation

• US 7,110,730 B2
• Filed: 02/26/2003
• Issued: 09/19/2006
• Est. Priority Date: 05/31/2002
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.), Renesas Technology Corporation (Renesas Electronics Corporation), Ttpcom Limited
• Original Assignee: Hitachi, Ltd., Ttpcom Limited
• Inventors: Okada, Kazuhisa, Wurm, Patrick, Hikasa, Kazuhiko, Freeborough, David
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US10/372,950
• Publication Number:
  US 20040198273A1
• Time in Patent Office: 1,301 Days
• Field of Search: 455/126, 455/127.1, 455/127.2, 455/127.3, 455/108, 455/110, 330/278, 330/296, 330/297, 332/144, 332/145
• US Class Current: 455/127.2
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 1/0266 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0272 by using a signal derived from the output signal
• CPC Class Codes: H03F 1/30 Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters in differential amplifiers H03F3/45479
• CPC Class Codes: H03F 1/345 using hybrid or directional couplers
• CPC Class Codes: H03F 2200/504 the supply voltage or current being continuously controlled by a controlling signal, e.g. the controlling signal of a transistor implemented as variable resistor in a supply path for, an IC-block showed amplifier
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control

Abstract

A mobile communication system has a mobile phone in which a voltage is set corresponding to the characteristic variation of a PA even when a PA having characteristic variation is used. The mobile phone employs a polar loop method, which comprises an antenna (1) for transmission and reception of signal waves; an antenna switch (2) for switching the transmission mode and the reception mode; a BBLSI (3) having a function to control the transmission and reception; an RFIC (4) having a function for modulating and demodulating the transmitted and received signals; and a PA (5) for amplifying up to the target output power by means of the amplitude modulation at the time of the transmission.

Claims

1. An apparatus for mobile communication system which performs signal transmission by amplitude modulation and phase modulation, comprising:

a power amplifier for amplifying a transmitting signal;

a control circuit for controlling transmitting and receiving of signals and capable of supplying a predetermined characteristic data for a bias voltage or a power source voltage of said power amplifier;

a radio frequency circuit for modulating the transmitting signal and demodulating a receiving signal; and

a controllable voltage source which receives said predetermined characteristic data from said control circuit and provides said bias voltage or said power source voltage in accordance with said predetermined characteristic data,

wherein said controllable voltage source includes a register for receiving and storing said predetermined characteristic data at a time of switching ON the apparatus and a digital to analog converter to output said bias voltage or said power source voltage based on said predetermined characteristic data stored in said register, and

wherein said controllable voltage source is included in said radio frequency circuit, and a connection for setting said bias voltage or said power source voltage between said power amplifier and said radio frequency circuit or said control circuit is formed by an analog interface.

2. An apparatus for mobile communication system, which performs signal transmission by amplitude modulation and phase modulation, comprising:

a power amplifier for amplifying a transmitting signal;

a control circuit for controlling transmitting and receiving of signals and capable of supplying a predetermined characteristic data for a bias voltage or a power source voltage of said power amplifier;

a radio frequency circuit for modulating the transmitting signal and demodulating a receiving signal; and

a controllable voltage source which receives said predetermined characteristic data from said control circuit and provides said bias voltage or said power source voltage in accordance with said predetermined characteristic data,

wherein said controllable voltage source including a register for receiving and storing said predetermined characteristic data at a time of switching ON the apparatus and a digital to analog converter to output said bias voltage or said power source voltage based on said predetermined characteristic data stored in said register, and

wherein said controllable voltage source is included in said control circuit, and a connection for setting said bias voltage or said power source voltage between said power amplifier and said control circuit is formed by a serial interface using digital signal.