Abstract: An exhaust gas processing system includes a cylindrical tube through which an exhaust gas of an engine passes, a sensor configured to detect information regarding the exhaust gas discharged from the engine, a coil antenna provided on an outer periphery of the cylindrical tube and connected to a high-frequency power supply, and a control unit configured to control output power of the high-frequency power supply. The control unit controls output power of the high-frequency power supply based on the information detected by the sensor.

Abstract: The present invention relates to an economical and highly reliable receiving apparatus for receiving radio signals transmitted from a mobile communication terminal within radio zone. The receiving apparatus has antenna sections that receive radio signals transmitted from the mobile communication terminal and are provided in each of a plurality of sectors divided from the radio zone, and receiving units that are provided in each of the antenna sections and that perform a predetermined process to the radio signals received by the antenna section.

Abstract: An attenuator of the current invention allows the adjustment in attenuation at a constant impedance level. The attenuator includes at least three variable resistors. Two of the three variable resistors have the substantially same linear resistance characteristics and are controlled in a substantially identical manner. One of the three variable resistors has a non-linear resistance characteristic and is controlled concurrently with the above two variable resistors. As a result of the above resistance characteristics and control, the attenuation is adjusted with respect to the resistance while impedance is maintained at a constant level.

Abstract: A feed forward type distortion compensation amplification apparatus includes a first division unit for dividing an input signal into a first channel signal and a second channel signal, a main amplifier for amplifying the first channel signal, a variable attenuation unit for processing the second channel signal to provide an amplitude adjusted second channel signal, a delay unit for delaying the amplitude adjusted second channel signal, a second division unit for dividing an output signal of the main amplifier into a third channel signal and a fourth channel signal and subtracting one of the third channel signal and the delayed second channel signal from the other to extract a distortion component introduced by the main amplifier, and a distortion compensation unit for removing a distortion component introduced into the fourth channel signal by the main amplifier, by using the distortion component extracted by the second division unit.

Abstract: A distortion compensation amplifier has a distortion detection loop that divides an input signal, amplifies one divided signal with an amplifier and uses the amplified signal and another divided signal to detect a distortion component generated and introduced into the amplified signal in the amplifier. The amplifier additionally has a distortion removal loop that removes the detected distortion component from the amplified signal produced by the amplifier. The distortion detection loop comprises a filter for reducing the distortion component of the amplified signal output by the amplifier that was generated and introduced into the amplified signal in the amplifier and detects the distortion component reduced by the filter. The distortion removal loop removes from the amplified signal the detected distortion component that was produced by the amplifier and reduced by the filter.

Abstract: A distortion compensation amplifier has a distortion detection loop that divides an input signal, amplifies one divided signal with an amplifier and uses the amplified signal and another divided signal to detect a distortion component generated and introduced into the amplified signal in the amplifier and a distortion removal loop that removes the detected distortion component from the amplified signal produced by the amplifier. The distortion detection loop comprises filter means for reducing the distortion component of the amplified signal output by the amplifier that was generated and introduced into the amplified signal in the amplifier and detects the distortion component reduced by the filter means. The distortion removal loop removes from the amplified signal the detected distortion component that was produced by the amplifier and reduced by the filter means.

Abstract: A feed forward type distortion compensation amplification apparatus includes a first division unit for dividing an input signal into a first channel signal and a second channel signal, a main amplifier for amplifying the first channel signal, a variable attenuation unit for processing the second channel signal to provide an amplitude adjusted second channel signal, a delay unit for delaying the amplitude adjusted second channel signal, a second division unit for dividing an output signal of the main amplifier into a third channel signal and a fourth channel signal and subtracting one of the third channel signal and the delayed second channel signal from the other to extract a distortion component introduced by the main amplifier, and a distortion compensation unit for removing a distortion component introduced into the fourth channel signal by the main amplifier, by using the distortion component extracted by the second division unit.

Abstract: An attenuator of the current invention allows the adjustment in attenuation at a constant impedance level. The attenuator includes at least three variable resistors. Two of the three variable resistors have the substantially same linear resistance characteristics and are controlled in a substantially identical manner. One of the three variable resistors has a non-linear resistance characteristic and is controlled concurrently with the above two variable resistors. As a result of the above resistance characteristics and control, the attenuation is adjusted with respect to the resistance while impedance is maintained at a constant level.

Abstract: The present invention relates to an economical and highly reliable receiving apparatus for receiving radio signal transmitted from a mobile communication terminal within radio zone. The receiving apparatus has antenna sections that receive radio signal transmitted from the mobile communication terminal and are provided in each of a plurality of sectors divided from the radio zone, and receiving units that are provided in each of the antenna sections and that perform a predetermined process to the radio signal received by the antenna section. Further, receiving apparatus has four cooling sections for receipt filter and LNA within two receiving units. Each of the cooling sections cools the same number of receipt filter and LNA.

Abstract: A metal-oxide semiconductor field-effect transistor (MOSFET) amplifier circuit includes a compensation circuit with a low cost MOSFET and a constant current circuit providing a constant drain current of the MOSFET, which maintains an operational point of the amplifier at an optimal state at all times. The MOSFET amplifier circuit includes a first MOSFET, a constant current circuit including a variable resistor, an operational amplifier, a power supply and a resistor, a second MOSFET having a constant current generated by the constant current circuit as a drain current thereof, and a voltage control circuit including operational amplifiers and resistors for applying a gate source voltage of the second MOSFET to the first MOSFET as a gate-source voltage thereof.