Patent application number | Description | Published |
20090051437 | POWER AMPLIFIER - An emitter follower circuit applies to an input terminal of a second amplifying device a voltage according to a reference voltage applied to a reference terminals. First and second resistors are connected in series between the reference terminal and an input terminal of a first amplifying device. The collector of a first transistor is connected to the reference terminal, and a control voltage is applied to the base of the first transistor. A third resistor is connected between the emitter of the first transistor and a grounding point. A current mirror circuit draws a current proportional to a current input from the collector of the first transistor from a connection point of the first and second resistors. | 02-26-2009 |
20090174484 | POWER AMPLIFIER - An amplifying transistor for amplifying a radio frequency signal between an input terminal and an output terminal. The cathode of a first diode is connected to the input terminal and the anode of a second diode is connected to the output terminal. A matching and attenuating circuit is connected between the anode of the first diode and the cathode of the second diode. A matching and attenuating circuit reduces impedance mismatches on the input terminal side and the output terminal side, and attenuates the radio frequency signal. In an amplification mode, a bias circuit supplies a bias current to an amplifying transistor and a current mirror circuit turns off the first and second diodes. In an attenuation mode, the bias circuit supplies no bias current to the amplifying transistor and the current mirror circuit turns on the first and second diodes. | 07-09-2009 |
20090309655 | POWER AMPLIFIER - A power amplifier includes: an amplifying transistor; a bias circuit; a first diode; a second diode; a matching attenuating circuit; a first current mirror circuit; a serial resonant circuit, and a switch. In an amplification mode, the bias circuit supplies a bias current to the amplifying transistor, and the first current mirror circuit turns off the first and second diodes, and the switch. In an attenuation mode, the bias circuit supplies no bias current to the amplifying transistor, and the first current mirror circuit turns on the first and second diodes, and the switch. | 12-17-2009 |
20100127689 | REFERENCE VOLTAGE GENERATION CIRCUIT AND BIAS CIRCUIT - A reference voltage generation circuit comprises: a first depletion mode FET; a second depletion mode FET; a first resistor; a first bipolar transistor; a second resistor; a second bipolar transistor; a third bipolar transistor; a third resistor; a third depletion mode FET having its drain connected to a second end of the first resistor and to the collector of the first bipolar transistor; and a fourth bipolar transistor having its base and collector connected to the gate and the source of the third depletion mode FET, and its emitter grounded, wherein source voltage of the second depletion mode FET is output as a reference voltage. | 05-27-2010 |
20100171564 | DIRECTIONAL COUPLER - A directional coupler includes a main line connected at a first end to an input port and at a second end to an output port, a coupled line connected at a first end to a coupled port and at a second end to an isolated port, and a phase shifter connected at a first end to the isolated port and at a second end to the coupled port. The phase shifter phase shifts a second reflected wave component such that the second reflected wave component is opposite in phase to a first reflected wave component, the second reflected wave component traveling from the output port to the coupled port through the isolated port and the phase shifter, the first reflected wave component traveling from the output port to the coupled port through the coupled line. | 07-08-2010 |
20110057746 | DIRECTIONAL COUPLER - A directional coupler includes capacitive elements electrically connected to a coupled port and an isolated port, respectively, for a coupled line on a chip (on-chip). The capacitive elements serve as matching capacitive elements and may be MIM (Metal Insulator Metal) capacitors on a substrate. A first end of a first of the capacitive elements is connected between the coupled port and the coupled line and a second end is grounded. A first end of a second of the capacitive elements is connected between the isolated port and the coupled line and a second end is grounded. | 03-10-2011 |
20110187349 | DETECTOR CIRCUIT AND SEMICONDUCTOR DEVICE USING SAME - A detector circuit for detecting degradation in the distortion characteristics of a power amplifier based on signals from both ends of a coupled line of a directional coupler. The detector circuit includes a phase shifter/attenuator for phase shifting and attenuating a signal from a coupled terminal of the coupled line, a differential amplifier for outputting difference between an output signal from the phase shifter/attenuator and a signal from the isolated terminal of the coupled line, a wave detector circuit for converting the difference into a DC signal, and a comparing circuit for determining whether the voltage level of the DC signal exceeds a predetermined level. When degradation in the distortion characteristics of the power amplifier arises, the phase shifter/attenuator phase shifts the signal from the coupled terminal and outputs a signal 180° out of phase with the signal from the isolated terminal. | 08-04-2011 |
20120062321 | POWER AMPLIFIER - A power amplifier comprises: an amplifying transistor for amplifying an input signal; a reference voltage generating circuit which generates a reference voltage; a bias circuit generating a bias voltage based on the reference voltage and supplying the bias voltage to the amplifying transistor; and a booster elevating an enable voltage input from outside and outputting the enable voltage. The reference voltage generating circuit is turned ON/OFF in correspondence with an output voltage of the booster. The booster includes: an enable terminal to which the enable voltage is applied; a power source terminal connected to a power source; a transistor having a control electrode connected to the enable terminal, a first electrode connected to the power source terminal, and a second electrode that is grounded; and a FET resistor connected between the first electrode of the transistor and the power source terminal. A gate electrode of the FET resistor is open. | 03-15-2012 |
20120154055 | POWER AMPLIFIER - A power amplifier includes a first amplifier unit, a second amplifier unit, and an attenuator. The second amplifier receives a signal from the first amplifier unit and amplifies the signal. The attenuator is provided between the first and second amplifier units. The attenuator has arms, including at least one parallel arm and at least one series arm, and has switches connected to the arms to switch the electrical connection states of the arms with respect to the first and second amplifier units. The at least one parallel arm and the at least one series arm are alternately arranged, in the order named, as viewed in the direction from the first amplifier unit to the second amplifier unit. | 06-21-2012 |
20140132358 | CASCODE AMPLIFIER - A cascode amplifier includes: first transistors; second transistors cascode-connected with respective first transistors; a first line connected at spaced points to control terminals of the first transistors; a second line connected at spaced points to control terminals of the second transistors; and a capacitance connected between one end of the second line and ground. The second line includes at least two lines connected in parallel with each other. | 05-15-2014 |
20140306761 | POWER AMPLIFIER - A power amplifier includes: first and second bias terminals to which bias voltages are respectively supplied; a first transistor having a first control terminal connected to the first bias terminal, a first terminal that is grounded, and a second terminal; a second transistor having a second control terminal connected to the second bias terminal, a third terminal connected to the second terminal, and a fourth terminal; a capacitor connected between the second control terminal and a grounding point; and a variable resistor connected in series with the capacitor, between the second control terminal and the grounding point. | 10-16-2014 |
20150054583 | POWER AMPLIFIER - A power amplifier includes: a first transistor having a gate, a drain, and a source that is grounded; a second transistor having a gate, a drain, and a source that is connected to the drain of the first transistor; a capacitor connected between the gate of the second transistor and a grounding point; an idling current control circuit having a positive temperatures coefficient and making an idling current flowing through the first transistor proportional to an ambient temperature; and a drain voltage control circuit having a positive temperature gradient coefficient and making a drain voltage on the first transistor proportional to the ambient temperature. | 02-26-2015 |