摘要:
A signal transceiver includes a first power amplifier coupled to a chip output port of a chip; an impedance transforming circuit; a switching circuit arranged to selectively couple the chip output port to a first port of the impedance transforming circuit; and a receiving amplifier coupled to a second port of the impedance transforming circuit.
摘要:
A signal transceiver includes a first power amplifier coupled to a chip output port of a chip; an impedance transforming circuit; a switching circuit arranged to selectively couple the chip output port to a first port of the impedance transforming circuit; and a receiving amplifier coupled to a second port of the impedance transforming circuit.
摘要:
The invention provides an amplifier circuit. In one embodiment, the amplifier circuit includes a first class-AB amplifier and a second class-AB amplifier. The first class-AB amplifier amplifies an input signal to generate the first output signal. The second class-AB amplifier amplifies the first output signal to generate a final output signal on an output node. When the power of the input signal is greater than a threshold level, the second class-AB amplifier is in a turned-off state during a turned-on duration period of the first class-AB amplifier, and the first class-AB amplifier is in a turned-off state during a turned-on duration period of the second-class AB amplifier.
摘要:
A low noise amplifier includes an input stage. The input stage includes a first device configured to receive an input signal. A second device is connected to the first device. The second device has a predetermined input impedance. The input stage is configured so that a change in the input signal to the first device causes a linearly proportional change in a conductance of the first device. A voltage at a junction between the first device and the second device remains substantially constant due to the predetermined input impedance of the second device.
摘要:
Circuits and methods are provided for generating reference currents. In one implementation, a circuit is provided that includes a first source and a current control circuit in communication with the first source. The first source generates a first reference current that is a ratio of a first reference voltage and an external resistance. The current control circuit produces a second reference current that is a ratio of a second reference voltage and the external resistance. The current control circuit produces the second reference current without being directly coupled to the external resistance.
摘要:
A geometric ladder circuit produces a transfer function having substantially uniform steps measured in dB. Where the ladder has a plurality of substantially identical resistor rungs of a first resistance, one stile that is a conductor connecting the rungs, and another having a series of substantially identical resistors of a second resistance, then for identical currents injected at different rungs, the output signal at an end of the ladder is attenuated by a number of substantially equal steps, one for each rung between input and output. For a ladder with a base rung R, an output at an end opposite the base rung, stile resistors of resistance αR, and other rungs all of resistance (1+(1/α))R, the step size is 20 log10(1+α).
摘要:
An LNA comprising an input stage to amplify an input signal. The input stage has a high linear transconductance that has reduced gain variations in response to changes in process and environmental conditions.
摘要:
A receiver includes a low noise amplifier (LNA), a passive mixer, a passive filter, a baseband processing block and a voltage controller. The LNA receives and amplifies a radio frequency (RF) signal. The passive mixer is coupled to the LNA without any AC coupling capacitance therebetween, and generates an intermediate frequency signal by down-converting the RF signal. The passive filter filters the intermediate frequency signal. The baseband processing block includes a transimpedance amplifier (TIA) and processes the filtered intermediate frequency signal. The voltage controller keeps a first node and a second node of a signal path to be around a common DC voltage, wherein the first node is located between an output terminal of the LNA and an input terminal of the passive mixer, and the second node is located between an output terminal of the passive mixer and an output terminal of the TIA.
摘要:
An embodiment of the invention provides a sliced transmitter front-end (TX FE). The sliced TX FE includes first TX FE slices and a second TX FE slice that are connected in parallel. As a whole the first TX FE slices contributes a high-gain section to a superimposed gain range of the sliced TX FE. The second TX FE slice has a gain range that constitutes a low-gain section of the superimposed gain range of the sliced TX FE. A minimum gain of the gain range of the second TX FE slice is smaller than a minimum gain of the high-gain section.
摘要:
A wireless communication receiver includes a first signal processing circuit, a second signal processing circuit, and a detecting circuit. The first signal processing circuit generates a first processed signal by processing a received radio frequency (RF) signal. The second signal processing circuit is coupled to the first signal processing circuit. The detecting circuit monitors a specific signal of the first signal processing circuit and generates at least a control signal to the second signal processing circuit in response to a signal level of the monitored specific signal. The control signal controls the second signal processing circuit to switch from a first operation mode to a second operation mode.