Abstract: A variable gain amplifier (VGA) is provided. The VGA includes at least one amplifier circuit, at least one current-steering circuit and at least one bias voltage circuit. Each current-steering circuit is coupled to its corresponding amplifier circuit. Each bias voltage circuit is coupled to its corresponding current-steering circuit to provide a positive bias voltage to each current-steering circuit.

Abstract: A variable gain amplifier (VGA) is provided. The VGA includes at least one amplifier circuit, at least one current-steering circuit and at least one bias voltage circuit. Each current-steering circuit is coupled to its corresponding amplifier circuit. Each bias voltage circuit is coupled to its corresponding current-steering circuit to provide a positive bias voltage to each current-steering circuit.

Abstract: An embodiment provides a variable gain amplifying method includes: on a signal path of a radio frequency input signal, amplifying a radio frequency input signal by a plurality of serially-coupled amplifiers; steering currents from the amplifiers and controlling respective gains of the amplifiers; performing gain match on the signal path of the radio frequency input signal; and performing phase compensation on the signal path of the radio frequency input signal. The signal path of the radio frequency input signal further has first and second phase variation trends which compensate each other.

Abstract: An embodiment provides a variable gain amplifying method includes: on a signal path of a radio frequency input signal, amplifying a radio frequency input signal by a plurality of serially-coupled amplifiers; steering currents from the amplifiers and controlling respective gains of the amplifiers; performing gain match on the signal path of the radio frequency input signal; and performing phase compensation on the signal path of the radio frequency input signal. The signal path of the radio frequency input signal further has first and second phase variation trends which compensate each other.

Abstract: The present disclosure provides a three-dimensional (3-D) transformer-based (TF-based) power amplifier architecture, including a power splitting plane having at least one input transformer-based circuit; and a power combining plane having at least one output transformer-based circuit. The power splitting plane includes at least one input transmission line, at least one input transformer and an input terminal. Moreover, the power combining plane includes at least one output transmission line, at least one output transformer, at least one power amplifier-cell (PA-cell) and an output terminal. The power combining plane is vertically stacked, attached and electrically connected to the power splitting plane. Consequently, as compared with the existing 2-D power amplifiers, the 3-D transformer-based power amplifier architecture of the present disclosure is capable of achieving a symmetric and compact power distribution layout.

Abstract: The present disclosure provides a three-dimensional (3-D) transformer-based (TF-based) power amplifier architecture, including a power splitting plane having at least one input transformer-based circuit; and a power combining plane having at least one output transformer-based circuit. The power splitting plane includes at least one input transmission line, at least one input transformer and an input terminal. Moreover, the power combining plane includes at least one output transmission line, at least one output transformer, at least one power amplifier-cell (PA-cell) and an output terminal. The power combining plane is vertically stacked, attached and electrically connected to the power splitting plane. Consequently, as compared with the existing 2-D power amplifiers, the 3-D transformer-based power amplifier architecture of the present disclosure is capable of achieving a symmetric and compact power distribution layout.

Abstract: A distributed active transformer (DAT) based millimeter-wave (MMW) power amplifier circuit is designed for power amplification of MMW frequency signals. The proposed MMW power amplifier circuit is characterized by distributing the input frequency signals into two sets of differential signals and by the use of a distributed active transformer circuit unit to process these two sets of differential signals to thereby generate an amplified frequency signal as the end result of output. The invention provides higher and greater added values and power added efficiency (PAE) and is ideal for use in millimeter-wave communications systems with an operation frequency around 60 GHz.

Abstract: A distributed active transformer (DAT) based millimeter-wave (MMW) power amplifier circuit is designed for power amplification of MMW frequency signals. The proposed MMW power amplifier circuit is characterized by distributing the input frequency signals into two sets of differential signals and by the use of a distributed active transformer circuit unit to process these two sets of differential signals to thereby generate an amplified frequency signal as the end result of output. The invention provides higher and greater added values and power added efficiency (PAE) and is ideal for use in millimeter-wave communications systems with an operation frequency around 60 GHz.