Samsung Electro-Mechanics Co., Ltd.

Young Wong Jang

Jeong Hoon Kim

Byeong Hak Jo

Jong Ok Ha

Hyun Paek

Shinichi Iizuka

Kwang Du Lee

Iizuka Shinichi

An apparatus that generates and limits a bias current of a power amplifier is provided. The apparatus includes a bias current circuit that generates a bias current to bias the power amplifier, and critically limit an increase in bias current, and a band gap reference circuit that provides a reference voltage or a reference current to the bias current circuit. The bias current circuit is configured to critically limit the increase in bias current, as a first bias transistor that generates the bias current is converted from a triode region to a saturation region, based on the reference voltage or the reference current.

Power amplifier with bias current generating and bias current limiting apparatus

A bias timing control circuit includes a current source, a bias switch circuit, a duty cycle sensing circuit, and a switching control circuit. The bias switch circuit includes a first path switch, connected between an output node of the current source and a bias amplifying circuit, and a second path switch, connected between the output node of the current source and a temperature compensation circuit. The duty cycle sensing circuit is configured to generate a timing control signal based on a duty cycle of a transmission enable signal. The switching control circuit is configured to control a first turn-on time of the first path switch during an initial startup period, and a second turn-on time of the second path switch during a normal driving period subsequent to the initial startup period to adjust a warm-up time of a power amplifying circuit based on the timing control signal.

Amplifying device with bias timing control circuit based on duty cycle

An amplifying apparatus is provided. The amplifying apparatus comprises an amplifying circuit comprising a power amplifier and a bias circuit, the bias circuit is configured to detect an ambient temperature of the power amplifier to output a temperature voltage and regulate an internal current based on an input control signal to supply a bias current obtained by the regulation to the power amplifier; and a temperature control circuit that generates the control signal based on the temperature voltage during initial driving from a transmission mode starting point in time to an input point in time at which an input signal is input and outputting the control signal to the amplifying circuit.

Amplifying apparatus with improved linearity

A bias circuit includes a current source to generate a reference current, a temperature compensation portion in an off-state in an initial start period in response to a first control signal, and in an on-state in a normal driving period, subsequent to the initial start period, and to receive a first current of the reference current, and a bias output portion to generate a warm up current based on the reference current in the initial start period and to generate a bias current based on a second current, which is lower than the reference current by an amount of the first current, in the normal driving period.

Bias circuit and power amplifier for improving linearity

A radio frequency switch apparatus includes a radio frequency switch, a dynamic bias circuit, and a switch control circuit. The radio frequency switch includes a first radio frequency switch circuit connected between a first signal terminal and an input terminal. The first radio frequency switch circuit includes a series switch and a shunt switch. The dynamic bias circuit is configured to generate a bias voltage and a buffer voltage lower than a battery voltage by a preset voltage, using the battery voltage and configured to output the bias voltage to a signal line connected to the input terminal. The switch control circuit is configured to generate first and second gate voltages to switch the first radio frequency switch circuit, based on a band selection signal, using the battery voltage and the buffer voltage.

Radio frequency switch apparatus having dynamic bias

A band selection switch apparatus includes: a first switch including a first series switch disposed between a transmission input terminal and a first transmission and reception terminal; a second switch including a second series switch disposed between the transmission input terminal and a first transmission terminal; and a third switch including a third series switch disposed between a first reception output terminal and the first transmission and reception terminal. The first series switch includes a first series switch circuit including first series switch elements connected between the transmission input terminal and a first intermediate node, a second series switch circuit including second series switch elements connected between the first intermediate node and the first transmission and reception terminal, and a first shunt switch circuit including first shunt switch elements connected between the first intermediate node and a ground.

Growing community of inventors

Suwon-si, South Korea

Young Wong Jang