3G radio
AssigneeAnalog Devices, Inc.
InventorsSimon Atkinson, Palle Birk
Life of this patent
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Abstract
A radio transceiver suitable for use in a mobile telephone is provided. The transceiver is operable in dual modes so as to be able to operate with both GSM and UMTS systems. In a preferred embodiment the transmitter section receives base band signals and up-converts them to an intermediate frequency of approximately 450 MHz. This is then mixed with local oscillator frequency of approximately 1.35 GHz, such that a difference frequency allows operation in the GSM 850/950 MHz band, and the sum frequency allows operation in the GSM 1800/1900 MHz bands. The frequency addition allows operation in the UMTS band. The receiver portion of the transceiver comprises a direct conversion receiver for down-converting the received signal without use of an intermediate frequency.
Claims13
A transceiver comprising a transmitter and a receiver, wherein a frequency synthesizer is shared by the transmitter and the receiver, wherein the transmitter comprises an up-converter for receiving an input and up-converting it to an intermediate frequency by mixing the input with a first synthesized frequency, and wherein in a GSM mode a phase locked loop is used to translate a phase modulated signal at an output of the up converter onto a radio frequency carrier, and in a UMTS mode the intermediate frequency signal is up-converted to a transmit frequency and linearly amplified;
- and wherein the receiver comprises a direct conversion receiver having at least one direct down conversion channel for down converting a received signal.
A transceiver comprising a transmitter and a receiver, wherein a frequency synthesiser is shared by the transmitter and the receiver, wherein the transmitter comprises an up-converter for receiving an input and up-converting it to an intermediate frequency by mixing the input with a first synthesised frequency, and wherein in a GSM mode a phase locked loop is used to translate a phase modulated signal at an output of the up converter onto a radio frequency carrier, and in a UMTS mode the intermediate frequency signal is up-converted to a transmit frequency land linearly amplified;
- and wherein the receiver comprises a direct conversion receiver having at least one direct down conversion channel for down converting a received signal and, in which the transceiver is operable to transmit and receive at a radio frequency, and in which the frequency synthesizer supplies a signal at a synthesizer frequency and wherein the transceiver is operable in at least two of the following modes:
- a. GSM 850 MHz receive mode, in which the synthesizer frequency is three times the radio frequency;
- b. GSM 900 MHz receive mode, in which the synthesizer frequency is three times the radio frequency;
- c. GSM 1800 MHz receive mode, in which the synthesizer frequency is 1.5 times the radio frequency;
- d. GSM 1900 MHz receive mode, in which the synthesizer frequency is 1.5 times the radio frequency;
- e. UMTS receive mode, in which the synthesizer frequency is 1.5 times the radio frequency;
- f. GSM 850 MHz transmit mode, in which the synthesizer frequency is three times the radio frequency and the intermediate frequency is half of the radio frequency;
- g. GSM 900 MHz transmit mode, in which the synthesizer frequency is three times the radio frequency and the intermediate frequency is half of the radio frequency;
- h. GSM 1800 MHz transmit mode in which the synthesizer frequency is 1.5 times the radio frequency and the intermediate frequency is one quarter of the radio frequency;
- i. GSM 1900 MHz transmit mode in which the synthesizer frequency is 1.5 times the radio frequency and the intermediate frequency is one quarter of the radio frequency;
- and a
- j. UMTS transmit mode in which the synthesizer frequency is 1.5 times the radio frequency and the intermediate frequency is ¼ of the radio frequency.
A transceiver comprising a transmitter and a receiver, wherein a frequency synthesiser is shared by the transmitter and the receiver, wherein the transmitter comprises an up-converter for receiving an input and up-converting it to an intermediate frequency by mixing the input with a first synthesised frequency, and wherein in a GSM mode a phase locked loop is used to translate a phase modulated signal at an output of the up-converter onto a radio frequency carrier, and in a UMTS mode the intermediate frequency signal is up-converted to a transmit frequency and linearly amplified:
- and wherein the receiver comprises a direct conversion receiver having at least one direct down conversion channel for down converting a received signal, and in which the transceiver is operable to transmit and receive at a radio frequency, and in which the frequency synthesizer provides in-phase and quadrature versions of a signal, and wherein the transceiver is operable in at least one of the following modes:
- a) GSM 850 MHz receive mode, in which the synthesizer frequency is 1.5 times the radio frequency;
- b) GSM 900 MHz receive mode, in which the synthesizer frequency is 1.5 times the radio frequency;
- c) GSM 1800 MHz receive mode, in which the synthesizer frequency is 0.75 times the radio frequency;
- d) GSM 1900 MHz receive mode, in which the synthesizer frequency is 0.75 times the radio frequency;
- e) UMTS receive mode, in which the synthesizer frequency is 0.75 times the radio frequency;
- f) GSM 850 MHz transmit mode, in which the synthesizer frequency is 1.5 times the radio frequency and an intermediate frequency is one half of the radio frequency;
- g) GSM 950 MHz transmit mode, in which the synthesizer frequency is 1.5 times the radio frequency and an intermediate frequency is one half of the radio frequency;
- h) GSM 1800 MHz transmit mode in which the synthesizer frequency is 0.75 times the radio frequency and an intermediate frequency is one quarter of the radio frequency;
- i) GSM 1900 MHz transmit mode in which the synthesizer frequency is 0.75 times the radio frequency and an intermediate frequency is one quarter of the radio frequency;
- and
- j) UMTS transmit mode in which the synthesizer frequency is 0.75 times the radio frequency and an intermediate frequency is one quarter of the radio frequency.
A transceiver comprising a transmitter and a receiver, wherein a frequency synthesiser is shared by the transmitter and the receiver, wherein the transmitter comprises an up-converter for receiving and input and up-converting it to an intermediate frequency by mixing the input with a first synthesised frequency, and wherein in a GSM mode a phase locked loop is used to translate a phase modulated signal at an output of the up converter onto a radio frequency carrier, and the phase locked loop is operable in a first GSM mode to form the sum of a frequency synthesised by the frequency synthesiser and the intermediate frequency, and the phase locked loop is operable in a second GSM mode to form a difference between the frequency synthesised by the frequency synthesiser and the intermediate frequency and in a UMTS mode the intermediate frequency signal is up-converted to a transmit frequency and linearly amplified;
- and wherein the receiver comprises a direct conversion receiver having at least one direct down conversion channel for down converting a received signal.
Dependencies are inferred from the claim text.