摘要:
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).
摘要:
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. Still further, when the high-frequency power amplifier (5) is operated as a nonlinear amplifier, by varying the input level of the high-frequency power amplifier (5) according to the average output power of the transmitting signal by the variable gain amplifier (7), it is possible to reduce leak power and to extend the control range of the transmitting output power.
摘要:
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.
摘要:
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.
摘要:
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.
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.