Abstract: A communication system is provided. The communication system includes an antenna, a power amplifier, a detector and a signal-processing module. The power amplifier provides an output signal to the antenna according to an input signal. The detector provides power information and voltage information according to the output signal. The signal-processing module obtains a loading variation according to the power information and the voltage information, and provides the input signal according to the loading variation. When the loading variation exceeds a threshold value, the signal-processing module performs a digital pre-distortion calibration for the input signal.

Abstract: A communication system is provided. The communication system includes an antenna, a power amplifier, a detector and a signal-processing module. The power amplifier provides an output signal to the antenna according to an input signal. The detector provides power information and voltage information according to the output signal. The signal-processing module obtains a loading variation according to the power information and the voltage information, and provides the input signal according to the loading variation. When the loading variation exceeds a threshold value, the signal-processing module performs a digital pre-distortion calibration for the input signal.

Abstract: A transforming circuit includes: a first winding having a first port and a second port operably coupled for a differential signal; and a plurality of second windings, each having a third port and a fourth port operably coupled for a single-ended signal when magnetically coupled to the first winding. When one of the second windings is magnetically coupled to the first winding, each remaining second winding(s) is not magnetically coupled to the first winding.

Abstract: Variable gain amplifiers with controllable gain gradient over temperature. A variable gain amplification circuit comprises an input terminal receiving an input signal, an output terminal outputting an output signal, and a control terminal receiving a first gain control signal. The relationship between gain of the variable gain amplification circuit and temperature is programmable rather than temperature independent, and is controlled by the first gain control signal obtained by a second gain control signal and a third gain control signal.

Abstract: A transforming circuit includes: a first winding having a first port and a second port operably coupled for a differential signal; and a plurality of second windings, each having a third port and a fourth port operably coupled for a single-ended signal when magnetically coupled to the first winding. When one of the second windings is magnetically coupled to the first winding, each remaining second winding(s) is not magnetically coupled to the first winding.

Abstract: An input/output device comprises a bonding pad, a signal transport circuit, and a blocking unit. The signal transport circuit has a first terminal connected to the bonding pad and a second terminal connected to a core circuit of an IC product. The signal transport circuit is capable of transporting a signal either from the bonding pad to the core circuit or from the core circuit to the bonding pad. The blocking unit has a control terminal and is coupled between the bonding pad and the signal transport circuit. The control terminal is coupled to receive an enable signal. The blocking unit ties the bonding pad to a predetermined voltage level when the enable signal is de-asserted, thereby blocking the signal transport provided by the signal transport circuit. The blocking unit unties the bonding pad from the predetermined voltage level when the enable signal is asserted.

Abstract: Variable gain amplifiers with controllable gain gradient over temperature. A variable gain amplification circuit comprises an input terminal receiving an input signal, an output terminal outputting an output signal, and a control terminal receiving a first gain control signal. The relationship between gain of the variable gain amplification circuit and temperature is programmable rather than temperature independent, and is controlled by the first gain control signal obtained by a second gain control signal and a third gain control signal.

Abstract: Linear-in-dB current generators having a maximum gain with least gain error. A first transistor is coupled between a first node and a first power voltage, and a first resistor is coupled between the first transistor and a second node. A second transistor is coupled between the second node and a second power voltage and comprises a control terminal coupled to the first node, and a third transistor comprises a first terminal coupled to the second power voltage, and a control terminal coupled to the first node. A second resistor is coupled between the third transistor and a third node, and a fourth transistor comprises a first terminal coupled to the first terminal, and a control terminal coupled to the third node. A first current source and the second current source are coupled to the second node and the third node respectively, and a reference current source is coupled to the first node.

Abstract: An input/output device comprises a bonding pad, a signal transport circuit, and a blocking unit. The signal transport circuit has a first terminal connected to the bonding pad and a second terminal connected to a core circuit of an IC product. The signal transport circuit is capable of transporting a signal either from the bonding pad to the core circuit or from the core circuit to the bonding pad. The blocking unit has a control terminal and is coupled between the bonding pad and the signal transport circuit. The control terminal is coupled to receive an enable signal. The blocking unit ties the bonding pad to a predetermined voltage level when the enable signal is de-asserted, thereby blocking the signal transport provided by the signal transport circuit. The blocking unit unties the bonding pad from the predetermined voltage level when the enable signal is asserted.

Abstract: Linear-in-dB current generators having a maximum gain with least gain error. A first transistor is coupled between a first node and a first power voltage, and a first resistor is coupled between the first transistor and a second node. A second transistor is coupled between the second node and a second power voltage and comprises a control terminal coupled to the first node, and a third transistor comprises a first terminal coupled to the second power voltage, and a control terminal coupled to the first node. A second resistor is coupled between the third transistor and a third node, and a fourth transistor comprises a first terminal coupled to the first terminal, and a control terminal coupled to the third node. A first current source and the second current source are coupled to the second node and the third node respectively, and a reference current source is coupled to the first node.

Abstract: A multi-band low noise amplifier comprising: a plurality of matching networks, a plurality of differential pairs, a pair of common base transistors, a pair of inductors, a pair of variable capacitors, a pair of inductors and a current generator. Bases of said plurality of differential pairs are coupled to outputs of said plurality of input matching networks. Emitters and collectors of said plurality of differential pairs are connected. Emitters of said common base transistor pairs are coupled to collectors of said plurality of differential pairs. The inductors are coupled to collectors of said common base transistor and a power supply. The capacitors and the inductors form a resonator pair. The inductors are coupled to emitters of said plurality of differential pairs. The inductor pairs are interlinked. The current generators are coupled to a coupling point of said inductors and to ground.

Abstract: A multi-band low noise amplifier comprising: a plurality of matching networks, a plurality of differential pairs, a pair of common base transistors, a pair of inductors, a pair of variable capacitors, a pair of inductors and a current generator. Bases of said plurality of differential pairs are coupled to outputs of said plurality of input matching networks. Emitters and collectors of said plurality of differential pairs are connected. Emitters of said common base transistor pairs are coupled to collectors of said plurality of differential pairs. The inductors are coupled to collectors of said common base transistor and a power supply. The capacitors and the inductors form a resonator pair. The inductors are coupled to emitters of said plurality of differential pairs. The inductor pairs are interlinked. The current generators are coupled to a coupling point of said inductors and to ground.