Patent EP0645899A2 successfully refreshed from Google Patents.
EP0645899A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Mobile communication apparatus with linear power control over wide dynamic range
Assignee: Hitachi Ltd
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Filing: 1994-09-23
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Granted: —
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Expires: 2014-09-23
Abstract
Abstract A mobile communication apparatus is provided, in which the linearity during a small output power of a radio-frequency power amplifier can be maintained as during a large output power. The input signal power to a radio-frequency power amplifier (11) is decreased by an attenuator (32) during a small power output. The resulting downward trend of the transmission signal power is compensated for by increasing the gain of the radio-frequency amplifier circuit (11) through a transmission power control circuit (14). Under this condition, the radio-frequency power amplifier (11) is made operable in a linear region of the transistor in the same manner as during a large power output. As a result, the linearity of the amplifier is guaranteed over the whole operating range of the transmission power.
Inventors
- 👤 Kunio Kobayashi
- 👤 Tetsuaki Adachi
- 👤 Tsuyoshi Shibuya
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 21:58
CPC Classifications
H; H04; H04W; H04W52/00; H04W52/04; H04W52/52; H03; H03F; H03F3/00; H03F3/20; H03F3/24; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3036; H03G3/3042
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
92 words
A mobile communication apparatus comprising a radio-frequency power amplifier for amplifying a modulation signal of a signal to be transmitted to control the transmission power, said apparatus comprising: means (12, 33) for decreasing an input signal power applied to the radio-frequency power amplifier on the basis of instructional information contained in a signal received from an external source, said instructional information instructing an output power of the radio-frequency power amplifier to be relatively decreased; and means (11) for increasing the gain of the radio-frequency power amplifier in response to said instructional information.
Claim 2
Dependent Claim
61 words
A mobile communication apparatus according to Claim 1, wherein said means for decreasing the input signal power includes an attenuator (12) for attenuating the power of said modulation signal with a gain in accordance with a control signal generated on the basis of said instructional information contained in said received signal and applying the attenuated signal to the radio-frequency power amplifier.
Claim 3
Dependent Claim
59 words
A mobile communication apparatus according to Claim 1, wherein said means for decreasing the input signal power includes a preamplifier (33) for amplifying said modulation signal with a gain determined in accordance with a control signal generated on the basis of the instructional information contained in said received signal and applying the preamplified signal to the radio-frequency power amplifier.
Claim 4
Dependent Claim
105 words
A mobile communication apparatus according to Claim 1, wherein said means for increasing the gain of the radio-frequency power amplifier includes: control means (18) for selecting and specifying one of a plurality of output power levels of the radio-frequency power amplifier in accordance with the instructional information contained in the signal received from an external source; means (13) for detecting the output power of the radio-frequency power amplifier; and transmission power control means (14) for controlling the gain of the radio-frequency power amplifier such that the power detected by said detection means coincides with the power specified by the instructional information from said control means.
Claim 5
Dependent Claim
169 words
A mobile communication apparatus comprising: an antenna (23); a radio-frequency receiving circuit (16, 17) for demodulating the signal received from the antenna; a modulation circuit (30) for modulating the signal to be transmitted from the antenna; a radio-frequency power amplifier (11) for oscillating the antenna on the basis of the output of the modulation circuit; a transmission power control circuit (14) for forming a control voltage for the radio-frequency power amplifier; a data processor (18) for giving an instruction on the transmission power to the transmission power control circuit in accordance with a signal instruction contained in the signal received from an external source; means (32) for decreasing the input signal power level of the radio-frequency power amplifier on the basis of the information representing an instruction applied from the data processor to the transmission power control circuit to decrease the output power of the radio-frequency power amplifier relatively; and means for changing the amplification bias (Vapc) of the radio-frequency power amplifier so as to increase the gain thereof.
Claim 6
Dependent Claim
51 words
A mobile communication apparatus according to Claim 5, wherein said means for decreasing the input signal power level includes an attenuator for attenuating the power of said modulation signal in accordance with the control signal applied from said data processor and applying the attenuated power signal to the radio-frequency power amplifier.
Claim 7
Dependent Claim
43 words
A mobile communication apparatus according to Claim 6, wherein said data processor instructs said attenuator to increase the amount of attenuation when the instruction on the transmission power applied to the transmission power control circuit specifies not more than a predetermined power level.
Claim 8
Dependent Claim
51 words
A mobile communication apparatus according to Claim 5, wherein said means for decreasing the input signal power level includes a preamplifier for power-amplifying the modulation signal with a gain in accordance with the control signal applied from said data processor and applying the power-amplified modulation signal to said radio-frequency power amplifier.
Claim 9
Dependent Claim
65 words
A mobile communication apparatus according to Claim 5, further comprising: a transmission power detection circuit (13) detecting the output power of the radio-frequency power amplifier; and a feedback circuit for said radio-frequency power amplifier including said transmission power detection circuit and said transmission power control circuit so that the power detected by said transmission power detection circuit coincides with the power level to be transmitted.
Claim 10
Dependent Claim
107 words
A mobile communication apparatus according to Claim 5, wherein said radio-frequency power amplifier includes a plurality of MOS transistor amplifiers connected in cascade, a circuit for applying the output of said input signal power decreasing means to the gate of a MOS transistor constituting an input amplifier, an output terminal connected in a manner to produce an amplified power from selected one of the source and the drain of a MOS transistor constituting an output amplifier, and a bias circuit for connecting the gates of the MOS transistors of the amplifiers in common and applying a gain control bias voltage variably from said transmission power control circuit.
Claim 11
Independent Claim
149 words
A method for controlling the transmission power of a mobile communication terminal comprising a radio-frequency power amplifier for amplifying the digital modulation signal of a signal to be transmitted, said method comprising the steps of: detecting information instructing a terminal transmission output to be relatively decreased, said information being contained in a signal received from a station administering communication with the other party; selectively attenuating by a predetermined amount the power level of a radio-frequency digital modulation signal generated at the terminal and modulated by the signal to be transmitted, on the basis of said instructional information; and applying the radio-frequency modulation signal of an attenuated power level at least to the radio-frequency power amplifier including at least one radio-frequency MOSFET and changing the gate bias of the radio-frequency MOSFET on the basis of the detected instructional information in a manner to increase the gain of the radio-frequency MOSFET.
Claim 12
Independent Claim
106 words
A method for controlling the transmission power of a mobile communication apparatus comprising a radio-frequency power amplifier for producing a transmission output by amplifying a radio-frequency digital modulation signal modulated by a telephone signal to be transmitted, said method comprising the steps of: detecting instructional information for instructing the transmission output of the apparatus to be decreased relatively, out of the signals received from a communication administration station external to the mobile communication apparatus; attenuating the input power to the radio-frequency power amplifier on the basis of the instructional information; and increasing the gain of the radio-frequency power amplifier on the basis of the instructional information.
References Cited (Backward Citations)
No citation records indexed.
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