[go: up one dir, main page]

EP0151148A1 - Transmitter with power amplifier control - Google Patents

Transmitter with power amplifier control

Info

Publication number
EP0151148A1
EP0151148A1 EP84902631A EP84902631A EP0151148A1 EP 0151148 A1 EP0151148 A1 EP 0151148A1 EP 84902631 A EP84902631 A EP 84902631A EP 84902631 A EP84902631 A EP 84902631A EP 0151148 A1 EP0151148 A1 EP 0151148A1
Authority
EP
European Patent Office
Prior art keywords
voltage
power
sourσe
output
signal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP84902631A
Other languages
German (de)
French (fr)
Inventor
Raymond William Simpson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Prutec Ltd
Original Assignee
Prutec Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Prutec Ltd filed Critical Prutec Ltd
Publication of EP0151148A1 publication Critical patent/EP0151148A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/30—Automatic control in amplifiers having semiconductor devices
    • H03G3/3036—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers
    • H03G3/3042—Automatic control in amplifiers having semiconductor devices in high-frequency amplifiers or in frequency-changers in modulators, frequency-changers, transmitters or power amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
    • H04W52/02—Power saving arrangements
    • H04W52/0209—Power saving arrangements in terminal devices
    • H04W52/0261—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level
    • H04W52/0296—Power saving arrangements in terminal devices managing power supply demand, e.g. depending on battery level switching to a backup power supply
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D30/00—Reducing energy consumption in communication networks
    • Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks

Definitions

  • the present invention relates to a mobile transmitter and is particularly concerned with making efficient use of power in the power amplifier of such a transmitter.
  • the output power is required to be regulated in discrete steps as commanded by a fixed base station.
  • the amount of power transmitted should be sufficient to provide clear communication with the nearest cell site but 3 should not be sufficiently powerful to interfere with the use of the same channel in nearby cell sites. For this reason, the mobile transmitter must be capable of regulating its power output in dependence upon a received command from the base station.
  • the transmitter When the transmitter is a portable radio telephone, it is important to maintain a high DC to RF power conversion efficiency at least at the higher power levels because this will help maximise battery life. It is not sufficient, however, to maximise only the highest power level efficiency as the portable radio telephone may also be operated at its second or third power levels for significant proportions of its battery life.
  • a mobile transmitter for use in a cellular system having a power output stage of which the output power is control ⁇ lable in dependence upon a received signal and a voltage supply for the output stage of the transmitter, wherein the voltage supply ⁇ omprises a low voltage source, a high voltage source and means for switching between the two voltage sources in dependence upon the power of the signal to be transmitted.
  • a mobile radio is often installed in a vehicle and for the purpose of powering other parts of the radio there is usually already provided a steady 5 V supply in addition to the vehicle's 12 V supply.
  • the 5 V supply is derived using a chopper circuit and is therefore an efficient means of stepping down the DC voltage.
  • use is made of the two existing voltages to supply the power output stage at different times depending upon the required power output. At the higher power levels, the output stage is conne ⁇ ted to the r-
  • FIG. 1 is a block circuit diagram of a mobile transmitter in accordance with the present invention.
  • Figure 2 is a more detailed circuit diagram of three of the blocks in Figure 1.
  • an input terminal 10 is arranged to receive a signal to be transmitted this being a modulated radio frequency signal.
  • the signal 10 is applied to a driver stage 12 the output of whi ⁇ h is fed to a power amplifier 14.
  • the output from the power amplifier 14 is fed to a transmitting antenna 16.
  • a signal from the fixed station is re ⁇ eived and applied to a latch cir ⁇ uit 18 by way of a terminal 20.
  • the demand signal lat ⁇ hed in the cir ⁇ uit 18 is de ⁇ oded by a de ⁇ oder 22 whi ⁇ h ⁇ onverts the re ⁇ eived digital signal into an analogue signal.
  • the analogue signal from the de ⁇ oder 22 is fed as a first input to a ⁇ omparator 24 setting the desired output level.
  • the ⁇ omparator 24 re ⁇ eives a se ⁇ ond input from an RF dete ⁇ tor 26 ⁇ onne ⁇ ted to the power output amplifier 14, this se ⁇ ond input to the ⁇ omparator being indi ⁇ ative of the a ⁇ tual transmitted level.
  • the ⁇ omparator 24 ⁇ ompares the desired and a ⁇ tual value of the transmitted power level and ⁇ ontrols the driver stage 12 to ⁇ omplete a negative feedba ⁇ k loop whi ⁇ h mat ⁇ hes the transmitted level to that demanded over the terminal 20.
  • the ⁇ ir ⁇ uit is ⁇ onventional and in su ⁇ h ⁇ onventional ⁇ ir ⁇ uits the power output amplifier is ⁇ onne ⁇ ted to re ⁇ eive a ⁇ onstant supply of voltage.
  • a power supply ⁇ ir ⁇ uit 30 is provided whi ⁇ h additionally alters the voltage supply to the power output amplifier 14 in dependen ⁇ e upon the analogue output signal of the de ⁇ oder 22.
  • a signal is applied to the base of a ⁇ ontrol transistor 30A whi ⁇ h forms part of the power supply ⁇ ir ⁇ uit.
  • the transistor 30A is ⁇ ondu ⁇ tive, a voltage drop a ⁇ ross its ⁇ olle ⁇ tor load resistor is applied to a power transistor 30B whi ⁇ h then be ⁇ omes ⁇ ondu ⁇ tive and enables a 12 V supply to be applied to the ⁇ olle ⁇ tor of a transistor 14A of the power output stage.
  • the ⁇ ir ⁇ uit enables the ⁇ olle ⁇ tor voltage of the power output transistor 14A to be varied in dependen ⁇ e upon the desired output level without resorting to inefficient vol ⁇ tage regulators and using only a second 5 V supply which is ordinarily present and provided by an efficient chopper cir ⁇ uit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Transmitters (AREA)

Abstract

Un émetteur mobile, utilisé dans un système radio cellulaire, possède un étage de puissance de sortie (14) et une alimentation en tension (30) fournissant une puissance à l'étage de sortie (14). L'alimentation en tension (30) possède une source à basse tension (+5 V) et une source à haute tension (+12 V). Un circuit de commutation relie de manière sélective l'une des deux sources de tension à l'étage de sortie (14) en réponse à un décodeur (22) prévu pour décoder un signal de demande codé numériquement et émis par une station de base.A mobile transmitter, used in a cellular radio system, has an output power stage (14) and a voltage supply (30) providing power to the output stage (14). The voltage supply (30) has a low voltage source (+5 V) and a high voltage source (+12 V). A switching circuit selectively connects one of the two voltage sources to the output stage (14) in response to a decoder (22) provided to decode a digitally encoded request signal transmitted from a base station.

Description

TRANSMITTER WITH POWER AMPLIFIER CONTROL
FIELD OF THE INVENTION;
The present invention relates to a mobile transmitter and is particularly concerned with making efficient use of power in the power amplifier of such a transmitter.
BACKGROUND OF THS INVENTION:
In portable radio telephones operating in cellular systems, the output power is required to be regulated in discrete steps as commanded by a fixed base station. By the nature of a cellular system, it is important that the amount of power transmitted should be sufficient to provide clear communication with the nearest cell site but 3 should not be sufficiently powerful to interfere with the use of the same channel in nearby cell sites. For this reason, the mobile transmitter must be capable of regulating its power output in dependence upon a received command from the base station.
When the transmitter is a portable radio telephone, it is important to maintain a high DC to RF power conversion efficiency at least at the higher power levels because this will help maximise battery life. It is not sufficient, however, to maximise only the highest power level efficiency as the portable radio telephone may also be operated at its second or third power levels for significant proportions of its battery life.
^O PI It has already been proposed to vary both the driver cur¬ rent into the power output stage and the collector voltage as the power requirements vary. The effect of altering the collector voltage is to alter the effective impedance of the power output stage whiσh is related both to the collector voltage and to the power transmitted. In the prior art, it has been suggested that the collector voltage be varied by the use of a voltage regulator but the losses involved in the voltage regulator mean that the total energy saving is not as high as it might be.
SUMMARY OF THE. INVENTON;
In accordance with the present invention, there is provided a mobile transmitter for use in a cellular system having a power output stage of which the output power is control¬ lable in dependence upon a received signal and a voltage supply for the output stage of the transmitter, wherein the voltage supply σomprises a low voltage source, a high voltage source and means for switching between the two voltage sources in dependence upon the power of the signal to be transmitted.
A mobile radio is often installed in a vehicle and for the purpose of powering other parts of the radio there is usually already provided a steady 5 V supply in addition to the vehicle's 12 V supply. The 5 V supply is derived using a chopper circuit and is therefore an efficient means of stepping down the DC voltage. In the present invention, use is made of the two existing voltages to supply the power output stage at different times depending upon the required power output. At the higher power levels, the output stage is conneσted to the r-
12 V sourσe whereas at lower power levels the output stage is σonnected to the 5 V sourσe.
BRIEF DESCRIPTION OF THE DRAWINGS;
The invention will now be desσribed further, by way of example, with referenσe to the aσcompanying drawings, in which:
Figure 1 is a block circuit diagram of a mobile transmitter in accordance with the present invention, and
Figure 2 is a more detailed circuit diagram of three of the blocks in Figure 1.
DETAILED DESCRIPTION OF THE EMBODIMENT;
Referring first to Figure 1, an input terminal 10 is arranged to receive a signal to be transmitted this being a modulated radio frequency signal. The signal 10 is applied to a driver stage 12 the output of whiσh is fed to a power amplifier 14. The output from the power amplifier 14 is fed to a transmitting antenna 16.
In order to regulate the amount of power transmitted, a signal from the fixed station is reσeived and applied to a latch cirσuit 18 by way of a terminal 20. The demand signal latσhed in the cirσuit 18 is deσoded by a deσoder 22 whiσh σonverts the reσeived digital signal into an analogue signal. The analogue signal from the deσoder 22 is fed as a first input to a σomparator 24 setting the desired output level. The σomparator 24 reσeives a seσond input from an RF deteσtor 26 σonneσted to the power output amplifier 14, this seσond input to the σomparator being indiσative of the aσtual transmitted level. The σomparator 24 σompares the desired and aσtual value of the transmitted power level and σontrols the driver stage 12 to σomplete a negative feedbaσk loop whiσh matσhes the transmitted level to that demanded over the terminal 20.
As so far desσribed, the σirσuit is σonventional and in suσh σonventional σirσuits the power output amplifier is σonneσted to reσeive a σonstant supply of voltage. In the present invention, in order to make more effiσient use of the battery power, a power supply σirσuit 30 is provided whiσh additionally alters the voltage supply to the power output amplifier 14 in dependenσe upon the analogue output signal of the deσoder 22.
To explain the σirσuit in more detail, referenσe is now made to Figure 2 whiσh shows in more detail the bloσks designated 14, 30 and 22 in Figure 1. To assist in the understanding of the σirσuit, elements falling within the blocks of Figure 2 have been designated by the same reference numerals. The deσoder 22 reσeives from the latσh σirσuit a σoded sig¬ nal indiσative of the demanded transmission level. Depend¬ ing on the value of the σode received from the latch cirσuit, an output is applied to one or other of the output lines whiσh may be seen to be σonneσted to resistors having different values. The values given in the drawing are intended only as an example. The voltage applied to the comparator from the σommon output of the resistors will depend upon the line over whiσh the signal is reσeived and this analogue value is used in the σomparator 24 to set the gain of the driver stage 12.
When the output from the deσoder is present on either one of the upper two lines in Figure 2 , these indiσating the highest two power output levels, a signal is applied to the base of a σontrol transistor 30A whiσh forms part of the power supply σirσuit. When the transistor 30A is σonduσtive, a voltage drop aσross its σolleσtor load resistor is applied to a power transistor 30B whiσh then beσomes σonduσtive and enables a 12 V supply to be applied to the σolleσtor of a transistor 14A of the power output stage. When a lower output power level is demanded, no signal is applied to the transistor 30A whiσh is therefore nonσonduσtive and the transistor 30B of the power supply will also be switσhed off. Under these σonditions, the transistor 14A of the power output stage is σonneσted to a 5 V supply whiσh is generated by a σhopper σirσuit driven by the 12 V supply. A Sσhottky diode 30C isolates the 5 V supply from the 12 V supply when the transistor 30B is con- duσtive.
Thus the σirσuit enables the σolleσtor voltage of the power output transistor 14A to be varied in dependenσe upon the desired output level without resorting to inefficient vol¬ tage regulators and using only a second 5 V supply which is ordinarily present and provided by an efficient chopper cirσuit.
It might be thought that the prinσiple of the present invention could be further refined by resorting to a chopper cirσuit σapable of providing not merely one, but two or more lower voltages from the 12 V supply already present. It has been surprisingly found that a σirσuit suσh as that illustrated in Figure 2 provides a higher DC to RF power σonversion efficiency at the three highest power levels of the transmitter than a cirσuit wherein a multiple output level σhopper is utilized to generate two rather than one lower voltage from the 12 V supply. This is beσause the power σonversion effiσienσy. of the transmitter is a function of the effiσienσies of both its power output stage and its power supply. It has been found that the improvement of power output stage effiσienσy resulting from using a third voltage is in faσt more than offset by the lower effiσiency of the power supply used to produce that voltage.
OMPI

Claims

1. A mobile transmitter for use in a σellular system, having a power output stage (14) of which the output power is controllable in dependence upon a received signal and a voltage supply for the output stage of the transmitter, wherein the voltage supply (30) σomprises a low voltage sourσe, a high voltage sourσe and means (30A, 30B) for switσhing between the two voltage sourσes in dependenσe upon the power of the signal to be transmitted.
2. A mobile transmitter as σlaimed in σlaim 1, wherein the lower voltage sourσe is derived by means of a σhopper σirσuit from the higher voltage sourσe.
3. A mobile transmitter as σlaimed in σlaim 1, wherein a deσoder (22) is provided for deσoding a digitally enσoded demand signal transmitted by a base station and produσing an output signal on one of the plurality of output lines in dependenσe upon the demand signal and switσhing means (30A) for varying the voltage sourσe connected to the power output stage when the output signal from the decoder is applied to predetermined ones of said output lines.
4. A mobile transmitter as claimed in claim 3, wherein the switσhing means σomprise a semiσonductor switch (30B) conneσted between the high voltage sourσe and the power output stage, the latter being σonnected to the low voltage sourσe by way of an isolation diode (30C) .
EP84902631A 1983-06-17 1984-06-04 Transmitter with power amplifier control Withdrawn EP0151148A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US50545783A 1983-06-17 1983-06-17
US505457 1995-07-21

Publications (1)

Publication Number Publication Date
EP0151148A1 true EP0151148A1 (en) 1985-08-14

Family

ID=24010389

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84902631A Withdrawn EP0151148A1 (en) 1983-06-17 1984-06-04 Transmitter with power amplifier control

Country Status (3)

Country Link
EP (1) EP0151148A1 (en)
AU (1) AU3103484A (en)
WO (1) WO1985000082A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0644716B2 (en) * 1984-08-14 1994-06-08 日本電気株式会社 Wireless communication device
US4636741A (en) * 1985-11-01 1987-01-13 Motorola, Inc. Multi-level power amplifying circuitry for portable radio transceivers
US7392023B2 (en) * 2003-03-27 2008-06-24 Nxp B.V. Power saving in a transmitter

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2844712A (en) * 1954-01-14 1958-07-22 Rca Corp Automatic power reducer for transmitters
US2896073A (en) * 1957-09-13 1959-07-21 Sinclair Oil & Gas Company Apparatus to automatically control transmitter power
US3151295A (en) * 1960-12-08 1964-09-29 Gen Electric Communication system employing means for adjusting the power between control and relay stations
US3900823A (en) * 1973-03-28 1975-08-19 Nathan O Sokal Amplifying and processing apparatus for modulated carrier signals
US4199723A (en) * 1978-02-24 1980-04-22 Rockwell International Corporation Automatic modulation control apparatus
JPS5694848A (en) * 1979-12-28 1981-07-31 Nec Corp Control system of transmitter

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8500082A1 *

Also Published As

Publication number Publication date
AU3103484A (en) 1985-01-11
WO1985000082A1 (en) 1985-01-03

Similar Documents

Publication Publication Date Title
US5029298A (en) Transmitter circuit
EP0248033B1 (en) Multi-level power amplifying circuitry for portable radio transceivers
US5613229A (en) Voltage and current mode power regulator
EP0626765B1 (en) Radio communication apparatus
EP0742509B1 (en) A method for reducing the power consumption of an electronic device
US6405054B1 (en) Apparatus for and method of improving efficiency of transceivers in radio products
EP0687060B1 (en) Power amplifier
JP3079095B2 (en) Power supply method and device for mobile communication terminal
EP0965183B1 (en) A circuit and method for controlling the power used by a portable radiotelephone
JP4159617B2 (en) COMMUNICATION SYSTEM, COMMUNICATION DEVICE, AND COMMUNICATION METHOD
US20020186076A1 (en) High frequency power amplifier
JPH11289577A (en) Power control system and method for variable power amplifier
US4155112A (en) Power supply circuitry
US5408691A (en) Radio transmitter apparatus which optimizes load impedance to maximize output transmitter efficiency while preserving minimum battery power output
CN1087521C (en) Method and apparatus for amplifying signal
EP0151148A1 (en) Transmitter with power amplifier control
KR910007680B1 (en) Apparatus for controlling the level of radio frequency power of portable phone
US5218285A (en) Electronic device with dual purpose regulator
EP0494529B1 (en) Portable telephone
KR960009926B1 (en) Method of controlling output power of mobile phones and power amplifiers of mobile phones
CA2163498C (en) Voltage and current mode power regulator
RU2161862C1 (en) Circuit and method for control of power used by portable radio telephone
JPH0685580A (en) Power controller
JPH1070473A (en) Radio transmitter and power amplifier circuit
JPS6112132A (en) Transmission output control circuit

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB LI LU NL SE

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB LI LU NL SE

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19850520

RIN1 Information on inventor provided before grant (corrected)

Inventor name: SIMPSON, RAYMOND, WILLIAM