摘要:
Provided is a transmission circuit capable of operating with high linearity and with low noise. An AM variable fc filter uses an AM cutoff frequency to remove a high frequency component from an amplitude signal. An amplifier supplies a power amplifier with a voltage which is a result of amplifying the amplitude signal outputted from the AM variable fc filter. A PM variable fc filter uses a PM cutoff frequency to remove a high frequency component from a phase signal. A phase modulator phase-modulates the phase signal outputted from the PM variable fc filter to output a high-frequency phase-modulated signal. The power amplifier amplifies the high-frequency phase-modulated signal by using the voltage supplied from the amplifier, and outputs a resultant signal as a transmission signal. The AM variable fc filter and the PM variable fc filter respectively control the AM cutoff frequency and the PM cutoff frequency such that the AM cutoff frequency and the PM cutoff frequency each have an opposite characteristic to that of an output power of the transmission signal.
摘要:
A modulator 23 corrects an amplitude signal Rd by adding thereto an offset value α and generates, based on the corrected amplitude signal Rd, an amplitude signal Ra for amplitude-modulating a radio-frequency signal. The modulator 23 includes: an offset voltage measurement section 109 operable to measure an offset voltage V2cal of the amplitude signal Ra; a correction value calculation section 110 operable to obtain a difference value ΔV2cal between the offset voltage V2cal measured by the offset voltage measurement section 109 and an initial value of the offset voltage V2cal and operable to calculate, based on the difference value ΔV2cal, a correction value VODAC for correcting the offset voltage V2cal; and an addition section 106 operable to add the correction value VODAC calculated by the correction value calculation section 110 to a signal processed until the amplitude signal Ra is generated from the amplitude signal Rd.
摘要:
A modulator 23 corrects an amplitude signal Rd by adding thereto an offset value α and generates, based on the corrected amplitude signal Rd, an amplitude signal Ra for amplitude-modulating a radio-frequency signal. The modulator 23 includes: an offset voltage measurement section 109 operable to measure an offset voltage V2cal of the amplitude signal Ra; a correction value calculation section 110 operable to obtain a difference value ΔV2cal between the offset voltage V2cal measured by the offset voltage measurement section 109 and an initial value of the offset voltage V2cal and operable to calculate, based on the difference value ΔV2cal, a correction value VODAC for correcting the offset voltage V2cal; and an addition section 106 operable to add the correction value VODAC calculated by the correction value calculation section 110 to a signal processed until the amplitude signal Ra is generated from the amplitude signal Rd.
摘要:
A wireless transmission apparatus of multi-mode operation with superior power efficiency is provided. Switches (115 and 117) are switched over in such a manner that a modulation signal outputted from a wireless GSM/EDGE (UB) signal formation circuit (101-3) of a high-frequency signal processing circuit (101) is outputted to a high-frequency power amplifier (104) at the time of output of a GSM modulation signal, and is outputted to a high-frequency amplifier (105) at the time of output of an EDGE modulation signal. As a result, the EDGE modulation signal is power amplified using a high-frequency power amplifier (105) for an UMTS modulation signal use that is compatible with regards to the EDGE modulation signal and the maximum output power and presence or absence of envelope fluctuation. It is therefore possible to amplify the EDGE modulation scheme wireless signal with high efficiency.
摘要:
To provide a drive unit and a drive module which include a shape memory alloy as a drive source to move a driven member and are capable of the high-precision movement of the driven member to a reference position. A drive unit and a drive module can be provided by controlling, in the drive unit and the drive module which include the shape memory alloy as the drive source to move the driven member, the shape memory alloy so that the resistance of the shape memory alloy is equal to the resistance when the driven member is located at the reference position.
摘要:
Provided is a Polar modulation apparatus which compensates for output characteristics of a power amplifier. A data generator generates an amplitude component signal and a phase component signal. A phase modulator generates a phase modulated signal obtained by phase modulating the phase component signal. An adder adds an amplitude offset voltage to the amplitude component signal. A power amplifier which includes a first hetero-junction bipolar transistor, amplifies the phase modulated signal by using the amplitude component signal. A monitor unit monitors the power amplifier and outputs a monitor voltage. The control unit calculates the amplitude offset voltage according to the monitor voltage and outputs the calculated amplitude offset voltage to the adder. The monitor unit includes a second hetero-junction bipolar transistor and outputs a collector emitter voltage of the second hetero-junction bipolar transistor as the monitor voltage.
摘要:
A drive device includes a setting unit 12 for setting a control value using a control value-displacement characteristic at a predetermined reference temperature showing a relationship between a control value used to position a movable unit 5 and a displacement of the movable unit 5; a drive unit 20 for supplying drive power corresponding to the control value set by the setting unit 12 to a shape-memory alloy 1 and causing the shape-memory alloy 1 to expand or contract, thereby positioning the movable unit 5; and a correction unit 13 for correcting the control value so as to correct a position shift of the movable unit 5 from a target position resulting from a difference between a control value-displacement characteristic at an ambient temperature and a control value-displacement characteristic at the reference temperature based on the ambient temperature detected by a temperature detection unit 11.
摘要:
In a first mode in which the power level of a transmission output signal (S6) is to be high, an output from the multiplier (2) is input to an amplitude modulation signal amplifier (4), and a radio frequency power amplifier (5) performs amplitude modulation on a radio frequency phase modulated signal (S4) using a nonlinear area with a supply voltage from the amplitude modulation signal amplifier (4). In a second mode in which the power level of a transmission output signal (S6) is to be low, the output from the multiplier (2) is input to a variable gain amplifier (7), and the variable gain amplifier (7) performs amplitude modulation on the radio frequency phase modulated signal (S4). The amplitude modulated signal is output without passing through the radio frequency power amplifier (5).
摘要:
An object of the preset invention is to provide a technique capable of preventing occurrence of an assembly error. A driving apparatus for driving an object includes: a driving part having a stationary part and a moving part; and a displacement transmitting part for transmitting a displacement to the object in accordance with a drive displacement of the moving part. The displacement transmitting part and the moving part coupled to the displacement transmitting part are integrally molded.
摘要:
An object of the present invention is to provide a small-sized image sensor device having high precision of moving an object to be moved. The image sensor device includes: a fixed unit; a movable unit including an image sensor; a beam unit fixed to the fixed unit and movably supporting the movable unit; a driving unit for applying a driving force for moving the movable unit; and a wire unit provided for the beam unit and electrically connecting the image sensor and an external circuit.