摘要:
A wireless transceiver including a receiver circuit coupled to an RF transceiver node, a tunable notch filter coupled between the RF transceiver node and a reference node, and a controller that programs the tunable notch filter with a selected blocker frequency and that selectively enables the tunable notch filter to attenuate at least one blocker signal. The tunable notch filter may include a variable capacitor and an inductor coupled in series between the RF transceiver node and ground. The inductor of the tunable notch filter may include a bondwire coupled between a semiconductor die and a semiconductor package. The inductance may include a physical inductor mounted on the package or a printed circuit board. The tunable notch filter may be enabled by a switch selectively coupling the filter to either the RF transceiver node or ground. The variable capacitor may be digitally programmed with digital values stored in a memory.
摘要:
A wireless transceiver circuit with an impedance matching network within an integrated circuit is disclosed. In some embodiments, the impedance matching network utilizes an inductor, having two portions, disposed on two different metal layers of the integrated circuit. The first end of the first portion of the inductor is in communication with an antenna. The second end of the second portion is in communication with a low noise amplifier for receiving signals and a power amplifier for transmitting RF signals. The second end of the first portion is connected to the first end of the second portion using a via. In another embodiment, the two portions are disposed on the same metal layer, wherein one portion is disposed within the other with a gap separating the two portions. These configurations require less space than using two separate inductors and also have a low coupling coefficient.
摘要:
Systems and methods are disclosed for on-chip harmonic filtering for radio frequency (RF) communications. For disclosed embodiments, a filter circuit is coupled between a first internal node and a connection pad for an integrated circuit. The filter circuit includes a first inductance, a variable capacitance, and a second inductance. The capacitance amount for the variable capacitance is controlled to tune filtering for the filter circuit to a harmonic of a frequency for a transmit output signal. A power amplifier outputs the transmit output signal to the connection pad without passing through the filter circuit. The filter circuit filters the harmonic of the frequency for the transmit output signal, shunting harmonic current to ground. For one embodiment, the filtered harmonic is a third harmonic of the transmit frequency. For one embodiment, the transmit output signal has an output power greater than or equal to 15 dBm.
摘要:
A transmitter including a frequency synthesizer with a voltage-controlled oscillator that provides an oscillating signal, a programmable delay circuit that delays the oscillating signal to provide a delayed oscillating signal, a power amplifier that is configured to use the delayed oscillating signal for transmitting a signal, and a delay controller that programs the delay circuit with a delay time that reduces interference caused by coupling from the power amplifier to the voltage-controlled oscillator. The delay circuit may be programmed to reduce control voltage change of the voltage-controlled oscillator as a function of delay change, and/or to reduce phase noise degradation at an output of the transmitter as a function of delay change. The delay may be adjusted based on detected operating temperature. A calibration value may be determined at a calibration frequency, in which a frequency offset may be determined based on a selected channel frequency.
摘要:
In one form, an integrated receiver includes a tracking bandpass filter, a tunable lowpass filter, and a mixer formed on a single integrated circuit chip. The tracking bandpass filter has an input for receiving a radio frequency (RF) input signal, and an output, and comprises a variable capacitor having a capacitance that varies in response to a bandpass frequency control signal, in parallel with an integrated inductor. The integrated inductor comprises a plurality of windings formed in a plurality of metal layers. The tunable lowpass filter has an input coupled to the output of the tracking bandpass filter, and an output and having a tuning input for receiving a cutoff frequency signal. The mixer has a signal input coupled to the output of the tunable lowpass filter, a local oscillator input for receiving a local oscillator signal, and a signal output for providing a converted RF signal.
摘要:
A method includes receiving a request to tune to a first desired television channel of a cable spectrum provided in a radio frequency (RF) signal received in a multi-tuner circuit configured to receive and process the entire cable spectrum, determining a channel of the channels including the first desired television channel, disabling the channels other than the determined channel, and processing the RF signal in the determined channel.
摘要:
An apparatus includes a splitter to receive a radio frequency (RF) signal and to provide the RF signal to multiple channels of a tuner. Each channel may include an amplifier to amplify the RF signal, a mixer to downconvert the amplified RF signal to a second frequency signal using a local oscillator (LO) signal, where each of the channels is configured to receive a different LO signal, a filter to filter the downconverted second frequency signal, and a digitizer to digitize the downconverted second frequency signal. A clock generation circuit has multiple interpolative dividers and a frequency synthesizer to generate a reference clock signal. Each of the interpolative dividers is configured to receive the reference clock signal, generate a corresponding LO signal, and provide the corresponding LO signal to the mixer of at least one of the channels.
摘要:
A transmitter including a frequency synthesizer with a voltage-controlled oscillator that provides an oscillating signal, a programmable delay circuit that delays the oscillating signal to provide a delayed oscillating signal, a power amplifier that is configured to amplify the delayed oscillating signal for transmission sufficient to produce interference, and a delay controller that programs the delay circuit with a delay time that reduces interference caused by coupling from the power amplifier to the voltage-controlled oscillator. The delay circuit may be programmed to reduce control voltage change of the voltage-controlled oscillator as a function of delay change, and/or to reduce phase noise degradation at an output of the transmitter as a function of delay change. The delay may be adjusted based on detected operating temperature. A calibration value may be determined at a calibration frequency, in which a frequency offset may be determined based on a selected channel frequency.
摘要:
A transmitter including a frequency synthesizer with a voltage-controlled oscillator that provides an oscillating signal, a programmable delay circuit that delays the oscillating signal to provide a delayed oscillating signal, a power amplifier that is configured to use the delayed oscillating signal for transmitting a signal, and a delay controller that programs the delay circuit with a delay time that reduces interference caused by coupling from the power amplifier to the voltage-controlled oscillator. The delay circuit may be programmed to reduce control voltage change of the voltage-controlled oscillator as a function of delay change, and/or to reduce phase noise degradation at an output of the transmitter as a function of delay change. The delay may be adjusted based on detected operating temperature. A calibration value may be determined at a calibration frequency, in which a frequency offset may be determined based on a selected channel frequency.
摘要:
A phase-locked loop (PLL) that provides a local oscillator signal for a radio. An oscillator of the PLL supplies an oscillator output signal. Control logic receives a request to change the oscillator output signal to a new frequency and responds to the request by setting a first capacitor circuit of the oscillator to a first capacitance that corresponds to a predetermined frequency of the oscillator output signal. The control logic also responds to the request by setting one or more other capacitor circuits of the oscillator according to temperature and according to a frequency difference between the predetermined frequency and the new frequency. After responding to the request by setting the first capacitor circuit and the one or more other capacitor circuits, the PLL locks to the new frequency using a signal from the PLL loop filter to adjust another capacitor circuit in the oscillator.