Abstract: The present innovation is directed to a single-chip integrated circuit power amplifier configured to employ the efficiency enhancement techniques utilized in Doherty amplifiers. The single-chip integrated circuit power amplifier may be implemented using uniquely designed biasing circuits as described herein. Also, the use of combined HBT/FET processes and a lumped quarter-wavelength transformer may be inherently well suited for the implementation of Doherty amplifiers in the single-chip techniques described herein.

Abstract: A transistor bias circuit is provided that is capable of biasing an amplifier transistor having a control terminal, a current-sink terminal, and a current-source terminal in order to control inter-modulation and linearize the output corresponding to radio frequency and microwave frequency ranges. Additionally, an embodiment of the present circuit is capable of dynamic power control. The transistor bias circuit according to the present invention utilizes a leakage current to alter the electrical characteristics of the amplifier transistor. The bias circuit comprises a bias transistor having a control terminal, a current-sink terminal, and a current-source terminal. Additionally, at least one DC input port, at least one resonator element, a diode element, and a resistive element is provided.

Abstract: A high gain, low noise amplifier having an active load with an inductor. The circuit may be fabricated, into a microwave monolithic integrated circuit using GaAs field effect transistors. The amplifier input is connected to the gate terminal of a first MESFET. A DC voltage source is connected to the drain terminal of the first MESFET via a low noise active load device having a second MESFET. The load device also includes an inductor connected between the drain terminal of the first MESFET and the source terminal of the second MESFET. The output terminal of the amplifier is connected to the drain terminal of the first MESFET.