Rafael Microelectronics, Inc.

Chih-Wen Wu

Po Chang Lin

Chun Hua Tseng

Szu-Yao Chu

A bias circuit generates a bias current to an RF power amplifier used for transmitting RF signals, and the amount of the bias current supplied to the RF power amplifier can be configured in multiple modes through transistor switches that are controlled by mode control signals, so that the bias current supplied to the RF power amplifier can be adjusted according to the required power level of the transmitting RF signals. In addition, the bias current can be turned off by another transistor switch that is controlled by a power control signal for saving power while the RF power amplifier is not transmitting RF signals.

Bias circuit for supplying a bias current to an RF power amplifier

A bias circuit for supplying a bias current to an RF power amplifier by using a field-effect transistor (FET) that is controlled by a logic control signal, such as a CMOS logic control signal, for turning on or turning off the bias current supplied to the RF power amplifier, wherein the bias current will be supplied to the RF power amplifier when the FET is on, and the bias current will not be supplied to the RF power amplifier when the FET is off.

Bias circuit based on BiFET technology for supplying a bias current to an RF power amplifier

A bias circuit for supplying a bias current to a RF power amplifier by using at least two voltage reference circuits coupled between the base terminal of a bipolar transistor and a voltage supply for generating a bias current to the RF power amplifier, wherein each of the at least two voltage reference circuits respectively clamps to a reference voltage at a corresponding terminal node of the voltage reference circuit on a conductive path having a current flowing from the voltage supply to the base terminal of the bipolar transistor, wherein when the current flowing out of the voltage supply increases, the current flowing through each of the at least two voltage reference circuits will also increases, so that the variation range of the bias current to the RF power amplifier will be kept in a smaller range compared with the variation range of the current flowing out of the power supply, thereby increasing the linearity of the RF power amplifier.

Growing community of inventors

Hsinchu County, Taiwan

Chih-Wen Wu