Abstract: A two-point frequency modulation apparatus is proposed whereby the spectrum of transmission waves is kept within the spectrum mask. Voltage is supplied to the control voltage terminal of VCO 1 in accordance with modulation data via noise shaper 101 that has operating characteristics of attenuating more noise at higher frequencies. As a result, by virtue of the working of noise shaper 101, the signal level outputted from the PLL circuit combining the modulation signal and the quantization noise decreases in proportion to the distance form the central frequency, so that two-point frequency modulation apparatus 100 is made possible whereby the spectrum of an RF modulation signal is kept within the spectrum mask.

Abstract: A transmission device having a preferable power efficiency and a wide control range of transmission output power. A pre-stage side of a high-frequency power amplifier changes an amplitude of a high-frequency phase modulation signal according to a base band amplitude modulation signal and a gain control signal. A variable gain amplifier changes the amplitude of the high-frequency phase modulation signal according to the base band amplitude modulation signal and the gain control signal, so that the base band amplitude modulation signal is supplied to an amplifier via a linear-log converter.

Abstract: Polar modulation transmission apparatus capable of suppressing power loss of a battery supply line to a high-frequency power amplifier regardless of whether transmission power is high or low is provided. Operation control section (120) performing control in such a manner that a battery voltage (S21) converted as a result of operation of a DC/DC converter (111) is applied to amplitude signal amplifying section (106) or halting operation of the DC/DC converter (111) in such a manner that battery voltage (S20) is applied directly from the battery (130) based on a transmission power control signal (S14). As a result, when transmission power is low, power loss at the amplitude signal amplifying section (106) is suppressed by DC/DC converter (111), unnecessary operation of DC/DC converter (111) is halted when transmission power is high, and power loss can be suppressed regardless of whether transmission power is high or low.

Abstract: The object of the present invention is to provide a transmitting apparatus and a transmitting power control method that can provide excellent power efficiency and a wide control range of transmitting output power, and a radio communication apparatus employing the transmitting apparatus. At the time of high output power, a high-frequency power amplifier (5) is operated as a nonlinear amplifier, whereby power efficiency when a transmitting signal is power-amplified can be enhanced. Further, at the time of low output power, the high-frequency power amplifier (5) is operated as a linear amplifier, whereby the control range of the transmitting output power can be extended.

Abstract: A transmitting apparatus includes a polar signal producing circuit which produces signals corresponding to the amplitude and the phase of a transmitting modulated wave from an input signal and multiplies the amplitude signal by the phase signal by a multiplying circuit to amplitude modulate a phase-modulated wave to produce a transmitting modulated wave and radiates this transmitting modulated wave as radio wave from an antenna. An amplitude/phase detecting circuit detects an amplitude signal and a phase signal from the input of the multiplying circuit and the input of a phase-modulated signal producing circuit.

Abstract: Either linear operating mode or saturation operating mode is set as the operating mode of a high-frequency power amplifier on the basis of an operating mode set signal. The gain of a variable gain amplifier provided in front of the high-frequency power amplifier and values of output voltage and bias current supplied from a supply voltage/bias current control circuit to the high-frequency power amplifier are switched. The gain of the variable gain amplifier in the saturation operating mode is formed so as to be higher by a predetermined value than that in the linear operating mode. Accordingly, the high-frequency power amplifier operates in the designated operating mode, so that the output transmission power range can be widened.

Abstract: A transmitting apparatus 100 operates a high-frequency power amplifier 105 as a nonlinear amplifier in a first mode, and operates high-frequency power amplifier 105 as a linear amplifier in a second mode. When high-frequency power amplifier 105 is operated as a nonlinear amplifier, the input level of high-frequency power amplifier 105 is varied by a variable gain amplifier 107 in accordance with the average output power of a transmit signal. Transmitting apparatus 100 is also provided with a compensation table 121 for reducing error in high-frequency power amplifier 105 mode switching operations.

Abstract: Linear transmission modulation apparatus 100 has high frequency amplifier 102 that amplifies the high frequency phase modulation signal of a high frequency signal and power source voltage controller 101 that amplifies the baseband amplitude modulation signal of the high frequency signal. Power source voltage controller 101 has delta sigma amplifier 103 that performs delta sigma amplifying of the baseband amplitude modulation signal and generates a delta sigma amplification signal and delta amplifier 104 that performs delta amplifying of the baseband amplitude modulation signal and generates a delta amplification signal. In response to a modulation mode switching control signal that indicates as to whether or not the amplitude modulation signal fluctuates, one of delta sigma amplifier 103 and delta amplifier 104 operates and sends out an output.

Abstract: There is provided a transmission device having a preferable power efficiency and a wide control range of transmission output power. At the pre-stage side of a high-frequency power amplifier (105) for changing the amplitude of a high-frequency phase modulation signal (S4) according to a base band amplitude modulation signal (S2) and a gain control signal (S12), there is provided a variable gain amplifier (201) for changing the amplitude of the high-frequency phase modulation signal (S4) according to the base band amplitude modulation signal (S2) and the gain control signal (S12), so that the base band amplitude modulation signal (S2) is supplied to a variable gain amplifier (203) via a linear-log conversion unit (206).

Abstract: A transmitter and method to output a stable output signal having low distortion by adjusting a delay time of an amplitude signal path and a phase signal path. In an amplitude phase extracting part, amplitude data and phase data are extracted from a transmit data signal and outputted. The amplitude of the amplitude data is modulated in an amplitude modulating part and an amplitude modulating signal is outputted; the phase of the phase data is modulated and a phase modulating signal is outputted. In a non-linear amplifying part, the phase modulating signal is multiplied by the amplitude modulating signal to output an RF signal with a prescribed gain amplified. A delay part provided in a pre-stage of the amplitude modulating part and a delay part provided in a pre-stage of the phase modulating part, respectively, adjusts the delay time of an amplitude signal path and a phase signal path.

Abstract: The object of the present invention is to automatically adjust the synchronization of an amplitude signal and a phase signal in a transmitting apparatus such as polar modulation transmitting apparatus. A polar signal producing circuit (101) produces signals corresponding to the amplitude and the phase of a transmitting modulated wave from an input signal and multiplies the amplitude signal by the phase signal by a multiplying circuit (107) to amplitude modulate a phase-modulated wave to produce a transmitting modulated wave and radiates this transmitting modulated wave as radio wave from an antenna (108). An amplitude/phase detecting circuit (109) detects an amplitude signal and a phase signal from the input of the multiplying circuit (107) and the input of a phase-modulated signal producing circuit (106).

Abstract: A power supply voltage control section 200 is provided with an adder 11 that adds together a baseband amplitude modulation signal 101 and a negative feedback signal, an integrator 12 that integrates the output of adder 11, a quantizer 13 that quantizes the output of integrator 12, and a low pass filter 14 that eliminates quantization noise from the output of quantizer 13, together with a compensator 15 that has an inverse characteristic of low pass filter 14 or a characteristic approximating thereto and performs compensation of the feedback amount of the negative feedback signal.

Abstract: Polar modulation transmission apparatus capable of suppressing power loss of a battery supply line to a high-frequency power amplifier regardless of whether transmission power is high or low is provided. Operation control section (120) performing control in such a manner that a battery voltage (S21) converted as a result of operation of a DC/DC converter (111) is applied to amplitude signal amplifying section (106) or halting operation of the DC/DC converter (111) in such a manner that battery voltage (S20) is applied directly from the battery (130) based on a transmission power control signal (S14). As a result, when transmission power is low, power loss at the amplitude signal amplifying section (106) is suppressed by DC/DC converter (111), unnecessary operation of DC/DC converter (111) is halted when transmission power is high, and power loss can be suppressed regardless of whether transmission power is high or low.

Abstract: An object of the invention is to provide a transmitter high in efficiency, good in linearity and capable of covering an output level in a wide range. Either linear operating mode or saturation operating mode is set as the operating mode of a high-frequency power amplifier (15) on the basis of an operating mode set signal (107). The gain of a variable gain amplifier (14) provided in front of the high-frequency power amplifier (15) and values of output voltage (109) and bias current supplied from a supply voltage/bias current control circuit (17) to the high-frequency power amplifier (15) are switched. The gain of the variable gain amplifier (14) in the saturation operating mode is formed so as to be higher by a predetermined value than that in the linear operating mode. Accordingly, the high-frequency power amplifier 15 operates in the designated operating mode, so that the output transmission power range can be widened.

Abstract: It is an object of the present invention to output a stable output signal having little distortion by adjusting a delay time of an amplitude signal path and a phase signal path. In an amplitude phase extracting part (2), amplitude data and phase data are extracted from a transmit data signal and outputted. Then, in an amplitude modulating part (3), the amplitude of the amplitude data is modulated and an amplitude modulating signal is inputted to a non-linear amplifying part (5) as a source voltage value. Further, in a phase modulating part (4), the phase of the phase data is modulated and a phase modulating signal is supplied to the non-linear amplifying part (5) as an input signal. In the non-linear amplifying part (5), the phase modulating signal is multiplied by the amplitude modulating signal to output an RF signal with a prescribed gain amplified.

Abstract: Linear transmission modulation apparatus 100 has high frequency amplifier 102 that amplifies the high frequency phase modulation signal of a high frequency signal and power source voltage controller 101 that amplifies the baseband amplitude modulation signal of the high frequency signal. Power source voltage controller 101 has delta sigma amplifier 103 that performs delta sigma amplifying of the baseband amplitude modulation signal and generates a delta sigma amplification signal and delta amplifier 104 that performs delta amplifying of the baseband amplitude modulation signal and generates a delta amplification signal. In response to a modulation mode switching control signal that indicates as to whether or not the amplitude modulation signal fluctuates, one of delta sigma amplifier 103 and delta amplifier 104 operates and sends out an output.

Abstract: A transmitting apparatus 100 operates a high-frequency power amplifier 105 as a nonlinear amplifier in a first mode, and operates high-frequency power amplifier 105 as a linear amplifier in a second mode. When high-frequency power amplifier 105 is operated as a nonlinear amplifier, the input level of high-frequency power amplifier 105 is varied by a variable gain amplifier 107 in accordance with the average output power of a transmit signal. Transmitting apparatus 100 is also provided with a compensation table 121 for reducing error in high-frequency power amplifier 105 mode switching operations.

Abstract: A two-point frequency modulation apparatus is proposed whereby the spectrum of transmission waves is kept within the spectrum mask. Voltage is supplied to the control voltage terminal of VCO 1 in accordance with modulation data via noise shaper 101 that has operating characteristics of attenuating more noise at higher frequencies. As a result, by virtue of the working of noise shaper 101, the signal level outputted from the PLL circuit combining the modulation signal and the quantization noise decreases in proportion to the distance form the central frequency, so that two-point frequency modulation apparatus 100 is made possible whereby the spectrum of an RF modulation signal is kept within the spectrum mask.

Abstract: To tune the center frequency of a gm-C filter, which is a bandpass filter with a narrow bandwidth, to a target frequency, only while the filter is being tuned, the original circuit configuration of the filter is replaced with an alternative configuration that realizes a high signal-to-noise ratio. A characteristic tuner generates and inputs an impulse signal, pulse signal or step signal to the filter being tuned and thereby detects and adjusts the center frequency of the filter. And the tuning result is stored on a nonvolatile memory for future reuse. When the filter is operated, the characteristic tuner stops operating to cut down the power dissipation.

Abstract: To tune the center frequency of a gm-C filter, which is a bandpass filter with a narrow bandwidth, to a target frequency, only while the filter is being tuned, the original circuit configuration of the filter is replaced with an alternative configuration that realizes a high signal-to-noise ratio. A characteristic tuner generates and inputs an impulse signal, pulse signal or step signal to the filter being tuned and thereby detects and adjusts the center frequency of the filter. And the tuning result is stored on a nonvolatile memory for future reuse. When the filter is operated, the characteristic tuner stops operating to cut down the power dissipation.