Richwave Technology Corp.

Trend Micro Inc.

Chih-Sheng Chen

Tien-Yun Peng

Ching-Wen Hsu

Hsien-Huang Tsai

Chang-Yi Chen

Jhao-Yi Lin

Tsung-Han Lee

Hung-Chia Lo

Hsiang-Jen Jao

Pei-Chuan Hsieh

Shr-an Su

Hang Chang

Po-Wei Wu

Yu-Siang Huang

Chia-Jung Yeh

Yao-Tang Chang

Ming-Shiuan Wen

Yu-Hsiang Chu

Chia-Wei Hsu

Chuan-Jane Chao

Hwey-Ching Chien

Chuan-Chen Chao

Chih-Che Lin

Yi-Chan Hung

Ching Wen Hsu

Sheng-Ting Chen

Yi-Bin Yang

Meng-Lun Li

Pin-Yi Huang

Hsien-Wei Ke

Chun-Hao Wei

Yun-Jhu Lai

Yu-Hsuan Chao

Hsuan-Der Yen

Chien-Yu Li

Sheng-Tsung Wang

Hong-Jia Lo

A radio frequency switch includes a signal terminal, a reference voltage terminal, and a shunt switch path. The shunt switch path includes a first transistor and a second transistor. The first transistor includes a first terminal coupled to the signal terminal, a second terminal, and a control terminal. The second transistor includes a first terminal coupled to the second terminal of the first transistor, a second terminal coupled to the reference terminal, and a control terminal. When the shunt switch path is switched to a first state, the shunt switch path has a first impedance. When the shunt switch path is switched to a second state, the shunt switch path has a second impedance, the first impedance and the second impedance being different. The first impedance is between 40 ohms to 85 ohms.

Radio frequency switch for reducing signal reflection

A compensation circuit includes a resistor-capacitor circuit and a control circuit. The resistor-capacitor circuit is used to generate a first voltage when a reference signal is in a first state, and generate a second voltage and a third voltage when the reference signal is in a second state. The resistor-capacitor circuit includes a first resistor-capacitor sub-circuit and a second resistor-capacitor sub-circuit. The first resistor-capacitor sub-circuit and the second resistor-capacitor sub-circuit are coupled to the control circuit, and operate simultaneously to compute an ON time of a front end module. The control circuit is coupled to the resistor-capacitor circuit, and is used to acquire the ON time according to the first voltage, the second voltage, and the third voltage, and includes an adjustment circuit used to generate a bias signal according to the ON time, and output the bias signal to the front end module.

Device of measuring duty cycle and compensation circuit utilizing the same

An amplifier circuit includes an amplifier for generating an amplified input signal according to an input signal, and an attenuator circuit coupled to the amplifier. The attenuator circuit includes an input terminal for receiving the input signal or the amplified input signal, an output terminal, a reference voltage terminal, a zeroth resistor-switch circuit, a first resistor-switch circuit, and a second resistor-switch circuit. The zeroth resistor-switch circuit includes a first terminal coupled to the input terminal, a second terminal coupled to the output terminal, a zeroth switch coupled to the first terminal of the zeroth resistor-switch circuit and the second terminal of the zeroth resistor-switch circuit, a zeroth resistor coupled between the first terminal of the zeroth resistor-switch circuit and the second terminal of the zeroth resistor-switch circuit, a first resistor coupled between the zeroth resistor and the second terminal of the zeroth resistor-switch circuit, and a first switch.

Gain-adjustable amplifier circuit

A feedback circuit coupled between an input terminal and an output terminal of an amplifier circuit includes an input terminal, an output terminal, a first set of transistors and a second set of transistors. The first set of transistors is coupled between the input terminal and the output terminal of the feedback circuit, and includes a first terminal, a second terminal, and a control terminal used to receive a first control signal to turn on or off the first set of transistors. The second set of transistors is coupled between the input terminal and the output terminal of the feedback circuit, and includes a first terminal, a second terminal, and a control terminal used to receive a second control signal to turn on or off the second set of transistors.

Feedback circuit with adjustable gain and radio frequency circuit utilizing the same

A driving circuit includes a first reference terminal, a second reference terminal, at least one input terminal, an output terminal, a first transistor, a second transistor, a switch module, and at least one control signal terminal. The at least one input terminal receives at least one input signal. The output terminal outputs an output signal in response to the at least one input signal. The first transistor and the second transistor respectively include control terminals coupled to the at least one input terminal. The switch module includes at least one control terminal coupled to the at least one control signal terminal to receive at least one control signal. The at least one input signal has a transition period. The switch module can be turned off according to the at least one control signal.

Driving circuit having a switch module to be capable of turning off a conductive path

A power amplifier has an amplifying transistor, a first resistor, a bias circuit, a second resistor, and a compensation circuit. The amplifying transistor amplifies a radio frequency (RF) signal to output an amplified RF signal. A control end of the amplifying transistor receives the RF signal. The first resistor provides a first resistance, and a second end of the first resistor is coupled to the control end of the amplifying transistor. The bias circuit has a bias transistor and is coupled to a first end of the first resistor. The second resistor provides a second resistance less than the first resistance, and a second end of the second resistor is coupled to the control end of the amplifying transistor. The compensation circuit has a compensation transistor, and an output end of the compensation circuit is coupled to a first end of the second resistor.

Power amplifier

A switch device structure includes RF1-st and RF2-nd input terminals, RFA-th, RFB-th and RFC-th output terminals, P2A-th, P1B-th and P1C-th paths, and first and second common paths. The P2A-th path includes a first terminal, and a second terminal coupled to the RFA-th output terminal. The P1B-th path includes a first terminal, and a second terminal coupled to the RFB-th output terminal. The P1C-th path includes a first terminal, and a second terminal coupled to the RFC-th output terminal. The first common path is coupled to the RF2-nd input terminal and the first terminal of the P2A-th path. The second common path is coupled to the RF1-st input terminal, the first terminal of the P1B-th path, and the first terminal of the P1C-th path. The first and second common paths cross each other on different planes to form a crossover.

Switch circuit structure having reduced crossovers and layout system thereof

A bias circuit includes a current mirror circuit, an operational amplifier, and a bias generating circuit. The current mirror circuit includes a reference branch circuit and at least one mirror branch circuit. The reference branch circuit generates a reference current according to a base current, and the at least one mirror branch circuit generates at least one mirrored current according to the reference current. The operational amplifier receives a first voltage from the reference branch circuit and a second voltage from the at least one mirror branch circuit, and adjusts the first voltage by generating a control voltage according to the second voltage. The bias generating circuit is coupled to the at least one mirror branch circuit and generates a bias signal according to the at least one mirrored current.

Bias circuit and amplifier device

A radio frequency (RF) switch includes a signal terminal, a reference voltage terminal and a shunt switch path. The shunt switch path includes a first sub-shunt circuit and a second sub-shunt circuit. The second sub-shunt circuit includes a first transistor and a second transistor coupled in parallel. When switched to a first state, the RF switch has first impedance; when switched to a second state, the RF switch has second impedance; and when switched to a third state, the RF switch has third impedance. The first impedance, the second impedance, and the third impedance are different.

Radio frequency switch

A switch device includes a driver circuit, a switch circuit and a level transition circuit. The driver circuit includes an input terminal for receiving an input signal, an output terminal for outputting an output signal, a first terminal coupled to a first reference terminal, and a second terminal coupled to a second reference terminal. The switch circuit includes a control terminal for receiving the output signal. The level transition circuit includes a first terminal for receiving the output signal, a second terminal coupled to a third reference terminal, and a third terminal for receiving the input signal. In a transition interval, the input signal is transitioned from a first input signal level to a second input signal level, the level transition circuit transitions the output signal from a first output signal level to a third output signal level between the first output signal level and a second output signal level.

Switch device capable of providing a discharge path according to signal level of an input signal

An amplifier circuit having an adjustable gain is provided. The amplifier circuit includes an input terminal, an output terminal, an amplifier, and an attenuation circuit. The input terminal receives an input signal, which is in turn received by an input terminal of the amplifier. An output terminal of the amplifier outputs the input signal that is amplified. The attenuation circuit is coupled between the output terminal of the amplifier and the output terminal to provide a plurality of attenuation to the input signal that is amplified and generate a first attenuation signal, or between the input terminal and the output terminal to provide the plurality of attenuations to the input signal and generate a second attenuation signal. A difference between an impedance value of the input terminal of the attenuation circuit and an impedance value of the output terminal of the attenuation circuit is within a predetermined range.

Amplifier circuit having adjustable gain

An amplifier circuit includes an input terminal used to receive an input signal, an output terminal used to output an output signal, an amplification unit, and a phase adjustment unit. The amplification unit includes an input terminal coupled to the input terminal of the amplifier circuit, an output terminal coupled to the output terminal of the amplifier circuit, a first terminal coupled to a first voltage terminal, and a second terminal coupled to a second voltage terminal. The phase adjustment unit is coupled to the amplification unit. When the amplifier circuit is operated in a first mode, the output signal has a first phase, and when the amplifier circuit is operated in a second mode, the output signal has a second phase. A difference between the first phase and the second phase is within a predetermined range.

Amplifier circuit

A switch device includes a first switch unit, a second switch unit, a first sub-switch unit, a second sub-switch unit, a first resistor and a second resistor. The first switch unit is coupled to a radio-frequency terminal and coupled to the second switch unit in cascode. The first sub-switch unit is coupled to the second sub-switch unit in cascode. The first sub-switch unit is further coupled between control terminals of the first switch unit and the second switch unit. The first sub-switch unit is further coupled to a node between the first resistor and the first switch unit. The second sub-switch unit is further coupled to a node between the second resistor and the second switch unit. When the first switch unit and the second switch unit are transitioned, the first sub-switch unit and the second sub-switch unit can be turned on to discharge and/or neutralize accumulated charges.

Switch device where charges accumulated at control terminals of switch units can be discharged and/or neutralized via sub-switch units

A switch device includes a first radio-frequency (RF) terminal, a second RF terminal, a first transistor, a second transistor, and a variable resistance element. The first transistor includes a first terminal coupled to the first RF terminal, a second terminal, and a control terminal coupled to a control signal terminal providing a control signal. The second transistor includes a first terminal coupled to the second terminal of the first transistor, a second terminal coupled to the second RF terminal, and a control terminal. The variable resistance element is coupled between the second terminal of the first transistor and a bias voltage terminal. When the first transistor and the second transistor are in a transient state, the variable resistance element provides a lower resistance. When the first transistor and the second transistor are in an ON state, the variable resistance element provides a higher resistance.

Switch device

An amplifier circuit includes a first amplifier and a second amplifier. The first amplifier receives a first signal and generates a first amplification signal accordingly. The second amplifier receives a second signal and generates a second amplification signal accordingly. The first signal is related to a first frequency band, and the second signal is related to a second frequency band different from the first frequency band. When one of the first amplifier and the second amplifier is in use, the other one of the first amplifier and the second amplifier is unused. The first amplifier and second amplifier are coupled to a reference voltage terminal through a common node. The first amplifier includes a switch coupled between the common node and a stage of the first amplifier, and the switch can be controlled for reducing the loading effect caused by the first amplifier on the second amplifier.

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Taipei, Taiwan

Chih-Sheng Chen