摘要:
A multimode wireless communication apparatus including a radio frequency unit having controllable communication mode and a control unit for periodically making the radio frequency unit operate in a mobile telephone mode and, after predetermined time, switching the mode to a wireless LAN mode, wherein if occurrence of an incoming call event is detected when the radio frequency unit is in standby reception in the mobile telephone mode, the control unit suppresses the switching to the wireless LAN mode and determines whether the communication in the mobile telephone mode should be continued or not.
摘要:
A multimode wireless communication apparatus including a radio frequency unit having controllable communication mode and a control unit for periodically making the radio frequency unit operate in a mobile telephone mode and, after predetermined time, switching the mode to a wireless LAN mode, wherein if occurrence of an incoming call event is detected when the radio frequency unit is in standby reception in the mobile telephone mode, the control unit suppresses the switching to the wireless LAN mode and determines whether the communication in the mobile telephone mode should be continued or not.
摘要:
In a direct conversion receiver, to cancel a DC offset generated in the baseband processing block, negative feedback arrangements comprising a gain control amplifier and a low-pass filter are respectively attached to the I and Q signal branches of the baseband block following mixer outputs. The gain control amplifier in each negative feedback circuit is gain adjusted so that the product G·B of the gain G of a primary gain control amplifier and its own gain B will be constant and thereby the DC offset is cancelled. This DC offset cancellation can be applied in a continuous receiving system with no intermittent time during a receiving operation. Capacitance elements located off-chip can be reduced to those to be used only in the low-pass filters in the negative feedback circuits, whereas many off-chip capacitance elements have been required to be inserted between each stage of gain control amplifiers in conventional baseband chains.
摘要:
In a direct conversion receiver, to cancel a DC offset generated in the baseband processing block, negative feedback arrangements comprising a gain control amplifier and a low-pass filter are respectively attached to the I and Q signal branches of the baseband block following mixer outputs. The gain control amplifier in each negative feedback circuit is gain adjusted so that the product G·B of the gain G of a primary gain control amplifier and its own gain B will be constant and thereby the DC offset is cancelled. This DC offset cancellation can be applied in a continuous receiving system with no intermittent time during a receiving operation. Capacitance elements located off-chip can be reduced to those to be used only in the low-pass filters in the negative feedback circuits, whereas many off-chip capacitance elements have been required to be inserted between each stage of gain control amplifiers in conventional baseband chains.
摘要:
A wireless communication receiver that is able to lessen the effect of noise that accompanies gain change by programmable gain amplifiers. The receiver includes an AGC controller which controls the timing at which the programmable gain amplifiers make gain change, using a terminal counter and a sequencer. The receiver prevents gain change noise signals during the reception of control signals and other signals that are susceptible to noise. By the timing control feature, the programmable gain amplifiers make gain change while reducing noise impact.
摘要:
A wireless communication receiver that is able to lessen the effect of noise that accompanies gain change by programmable gain amplifiers. The receiver includes an AGC controller which controls the timing at which the programmable gain amplifiers make gain change, using a terminal counter and a sequencer. The receiver prevents gain change noise signals during the reception of control signals and other signals that are susceptible to noise. By the timing control feature, the programmable gain amplifiers make gain change while reducing noise impact.
摘要:
In a direct conversion receiver, to cancel a DC offset generated in the baseband processing block, negative feedback arrangements comprising a gain control amplifier and a low-pass filter are respectively attached to the I and Q signal branches of the baseband block following mixer outputs. The gain control amplifier in each negative feedback circuit is gain adjusted so that the product G-B of the gain G of a primary gain control amplifier and its own gain B will be constant and thereby the DC offset is cancelled. This DC offset cancellation can be applied in a continuous receiving system with no intermittent time during a receiving operation. Capacitance elements located off-chip can be reduced to those to be used only in the low-pass filters in the negative feedback circuits, whereas many off-chip capacitance elements have been required to be inserted between each stage of gain control amplifiers in conventional baseband chains.
摘要:
Methods for producing a semiconductor layer and for producing a photoelectric conversion device, semiconductor raw material are disclosed. An embodiment of the method for producing a semiconductor layer includes: forming a film containing a metal element and an oxygen element; generating oxygen gas by heating the film; and forming a semiconductor layer containing a metal chalcogenide from the film by allowing the metal element to react with a chalcogen element. Another embodiment of the method includes forming a lower film containing a metal element; forming an upper film, which contains the metal element and a substance that contains oxygen, on the lower film; generating oxygen gas by heating the substance; and forming a semiconductor layer containing a metal chalcogenide from the lower film and the upper film by allowing a chalcogen element to react with the metal element in the lower film and the upper film.
摘要:
A photoelectric conversion device is disclosed. The photoelectric conversion device includes an electrode layer and a semiconductor layer. The semiconductor layer is located on the electrode layer and contains a group I-III-VI compound. In the semiconductor layer, an atomic ratio of a group I-B element to a group III-B element decreases from one principal surface side of the semiconductor layer on the electrode layer side to a central portion in a thickness direction and increases from the central portion to another principal surface side on a side opposite to the electrode layer.
摘要:
A high frequency circuit and a high frequency module are provided, in which the accuracy of compensation operation is improved in compensating by digital control. The amplification gain of an amplification element of an amplifier unit is controlled by a bias current of a bias control unit. A process monitoring circuit of a calibration circuit includes a first and a second element characteristic detector and a voltage comparator. The detectors convert the current of replica elements into a first and a second detection voltage. The voltage comparator compares a first and a second detection voltage and supplies a comparison output signal to a search control unit. Responding to the comparison output signal of the comparator and a clock signal of a clock generating unit, the controller generates a multi-bit digital compensation value according to a predetermined search algorithm, and the bias control unit of the second detector is feedback-controlled.