A circuit for generating a radio frequency signal is provided. The circuit includes an amplifier configured to generate a radio frequency signal based on a baseband signal. Further, the circuit includes a power supply configured to generate a variable supply voltage based on a control signal indicating a desired supply voltage, and to supply the variable supply voltage to the amplifier. The circuit further includes an envelope tracking circuit configured to generate the control signal based on a bandwidth of the baseband signal, and to supply the control signal to the power supply.

A circuit for generating a radio frequency signal is provided. The circuit includes an amplifier configured to generate a radio frequency signal based on a baseband signal. Further, the circuit includes a power supply configured to generate a variable supply voltage based on a control signal indicating a desired supply voltage, and to supply the variable supply voltage to the amplifier. The circuit further includes an envelope tracking circuit configured to generate the control signal based on a bandwidth of the baseband signal, and to supply the control signal to the power supply.

An aspect includes a filtering method including operating a first filter to filter a first input signal to generate a first output signal; operating a second filter to filter a second input signal to generate a second output signal; and selectively coupling at least a portion of the second filter with the first filter to filter a third input signal to generate a third output signal. Another aspect includes a filtering method including operating switching devices to configure a filter with a first set of pole(s); filtering a first input signal to generate a first output signal with the filter configured with the first set of pole(s); operating the switching devices to configure the filter with a second set of poles; and filtering a second input signal to generate a second output signal with the filter configured with the second set of poles.

A system, method and apparatus for simultaneously minimizing power and latency in a scan for advertisement packets from one or more peripheral devices in a Bluetooth Low Energy (BLE) frequency band having a number of advertisement channels. A receiver front end receives BLE signals, and a local oscillator (LO) generator has an output frequency that is sequentially tuned to a frequency of each of the advertisement channels. An energy detector monitors signal energy on each of the advertisement channels in sequence, and when the signal energy exceeds a threshold, fixes the output frequency of the LO generator to that advertisement channel. An automatic gain controller controls a gain of the signal on the one of the plurality of advertisement channels to generate a controlled gain signal, and a correlator correlates the controlled gain signal with an advertisement packet on the one of the advertisement channels.

A communications receiver with improved blocker performance including multiple gain tables selected based on a number of reductions or back offs from a maximum coarse gain setting. A receiver chain with multiple gain stages converts a received signal to a digital format, determines the power level of the received signal, and provides an overload indication. A first gain table maximizes SNR and SNDR for weak blockers and at least one additional gain table successively improves SNDR for stronger blockers. An AGC circuit initially sets the coarse gain setting to maximum, and backs off a number of coarse gain steps until the receiver chain is not overloaded. The number of back off steps is used to select a gain table, the power level is used to select an entry in the selected table, and the selected entry includes gain settings for the gain stages of the receiver chain.

An aspect includes a filtering method including operating a first filter to filter a first input signal to generate a first output signal; operating a second filter to filter a second input signal to generate a second output signal; and selectively coupling at least a portion of the second filter with the first filter to filter a third input signal to generate a third output signal. Another aspect includes a filtering method including operating switching devices to configure a filter with a first set of pole(s); filtering a first input signal to generate a first output signal with the filter configured with the first set of pole(s); operating the switching devices to configure the filter with a second set of poles; and filtering a second input signal to generate a second output signal with the filter configured with the second set of poles.

A gain controller sets a gain code indicating an optimum gain, a cutoff frequency code indicating a cutoff frequency, and a number of bits code indicating a number of bits. An AEQ/VGA gain controller sets a frequency characteristic code indicating a frequency characteristic, a gain code indicating a gain after correction, and a number of bits code indicating a number of bits. An AEQ/VGA amplifies a baseband received signal on the basis of a gain code and corrects a frequency characteristic of the baseband received signal on the basis of a frequency characteristic code. An HPF cuts off a band below a cutoff frequency of an output signal from the AEQ/VGA on the basis of a cutoff frequency code. An ADC quantizes an output signal from the HPF using a number of bits based on a number of bits code and generates a digital received signal.

A gain controller sets a gain code indicating an optimum gain, a cutoff frequency code indicating a cutoff frequency, and a number of bits code indicating a number of bits. An AEQ/VGA gain controller sets a frequency characteristic code indicating a frequency characteristic, a gain code indicating a gain after correction, and a number of bits code indicating a number of bits. An AEQ/VGA amplifies a baseband received signal on the basis of a gain code and corrects a frequency characteristic of the baseband received signal on the basis of a frequency characteristic code. An HPF cuts off a band below a cutoff frequency of an output signal from the AEQ/VGA on the basis of a cutoff frequency code. An ADC quantizes an output signal from the HPF using a number of bits based on a number of bits code and generates a digital received signal.

A circuit for generating a radio frequency signal is provided. The circuit includes an amplifier configured to generate a radio frequency signal based on a baseband signal. Further, the circuit includes a power supply configured to generate a variable supply voltage based on a control signal indicating a desired supply voltage, and to supply the variable supply voltage to the amplifier. The circuit further includes an envelope tracking circuit configured to generate the control signal based on a bandwidth of the baseband signal, and to supply the control signal to the power supply.

A peak detector including an input circuit with five same-sized transistors, in which four of the input transistors are coupled in parallel between a control node and a bias node and receive a corresponding one of two in-phase signals and two quadrature signals. The fifth transistor is coupled between a current node and the bias node and has its control terminal coupled to an output node. A bias circuit establishes a predetermined bias current that flows through the five input transistors. A current mirror mirrors the current through the fifth transistor from the current terminal into the four parallel-coupled input transistors via the control node. An output circuit charges a peak capacitor based on voltage developed at the control terminal of the fifth transistor. The peak detector is low power and compact and detects the actual peak of the input signal with greater accuracy compared to a conventional peak detector.