摘要:
According to one exemplary embodiment, a transceiver for nullification of a noise component in a transmitter comprises a noise nullification module loading a selected node in the transmitter. The noise nullification module comprises a mixer that receives inputs from the selected node and a local oscillator, where the mixer is also coupled to a filter such that the noise nullification module presents a low impedance at an approximate frequency of a noise component so as to nullify the noise component. In one embodiment, the noise nullification module results in band-pass filtering of an approximate receive signal frequency so as to nullify a noise component at the receive frequency. In another embodiment, the noise nullification module results in notch filtering of an approximate transmit signal frequency so as to nullify a noise component at a receive signal frequency.
摘要:
A method and system for wireless communication is provided and may include mitigating blocker signals in transmitted RF signals in a wireless device including a transmitter front end. The mitigation may include up-converting a baseband signal, mixing the up-converted baseband signal with a feedback signal, and amplifying the mixed up-converted baseband signal and the feedback signal to generate an output signal. The feedback signal may be generated by down-converting the output signal, low-pass filtering the down-converted output signal, and up-converting the filtered down-converted signal for the summing. The blocker signals may correspond to receive frequencies for the wireless device and may be converted to DC via the down-converting. The wireless devices may operate in accordance with at least a CDMA standard. The mixed up-converted baseband signal and the feedback signal may be amplified utilizing a source follower amplifier, where the gain and/or linearity may be configured by varying coupling capacitors.
摘要:
Embodiments enable a multi-band transmitter with significantly reduced architecture area by allowing maximum reuse of transmitter stages across supported frequency bands and signal standards. Further, embodiments allow a monolithic transmitter implementation by providing an integration-friendly differential to single-ended conversion stage. According to embodiments, the differential to single-ended conversion stage is readily configurable according to the frequency band and signal standard of operation of the transmitter.
摘要:
According to one embodiment, a peak detector having extended dynamic range comprises a first differential output coupled to a supply voltage of the peak detector by a first load and coupled to ground by first and second switching devices, and a second differential output coupled to the supply voltage by a second load and coupled to ground by third and fourth switching devices. The control terminals of the first, second, third, and fourth switching devices receive a common bias voltage, and the respective first and second control terminals are configured as differential inputs of the peak detector. In some embodiments, corresponding first power terminals of the first and second switching devices share a first common node further shared by the first differential output, and corresponding first power terminals of the third and fourth switching devices share a second common node further shared by the second differential output.
摘要:
Aspects of a method and system for transmitter linearization are provided. A signal may be amplified via one or more circuits comprising a first transistor having a first bias voltage applied to its gate via a resistor, and a second transistor having its source coupled to a first terminal of the resistor, its drain coupled to a second terminal of the resistor, and its gate coupled to a second bias voltage. The signal may be AC-coupled, via one or more capacitors, for example, to the gate of the first transistor. The first bias voltage and the second bias voltage may be such that the first transistor operates in the active region the second transistor operates in the subthreshold region. The effective channel width of the second transistor may be configurable during operation of the one or more circuits.
摘要:
Embodiments of the present invention enable a feedback-based VCO linearization technique. Embodiments include a frequency locked loop formed by feeding back a VCO's output into the VCO's input in negative phase by means of a frequency-to-voltage (F/V) converter. Embodiments enable constant VCO gain over a wide input tuning range and across PVT variations. Further, embodiments can be nested within a PLL, for example, with negligible area and power consumption overhead.
摘要:
According to one embodiment, an improved preamplification chain for implementation in a transmitter comprises a frequency conversion stage for up-converting a baseband signal to a transmit signal, a variable gain control power amplifier driver for preamplifying the transmit signal, and a differential feedback calibration stage receiving first and second differential outputs of a current steering unit of the power amplifier driver and providing calibration feedback to a baseband signal generator of the transmitter. In one embodiment, the frequency conversion stage includes an adjustable low-pass filter for filtering the baseband signal, a passive mixer for up-converting the baseband signal to the transmit signal, and a clock conversion unit configured to convert a fifty percent (50%) duty cycle clock input to a twenty-five percent (25%) duty cycle clock output for driving the passive mixer.
摘要:
According to one embodiment, a radio frequency (RF) transceiver includes a transmitter enabling efficient preamplification gain control. The RF transceiver comprises a receiver and a power amplifier (PA) for amplifying a transmit signal of the transmitter. The transmitter is configured to provide pre-PA gain control for preamplifying the transmit signal before amplification by the PA, wherein substantially all of the pre-PA gain control is provided when the transmit signal is at a transmit frequency of the transmitter. In one embodiment, the transmitter includes a PA driver comprising in combination: a transconductance amplifier, a current steering block, and an output transformer. Each of the transconductance amplifier, current steering block, and output transformer is configured to contribute a respective variable gain control to the pre-PA gain control provided by the PA driver.
摘要:
A SAW-less receiver includes an FEM interface module, an RF to IF receiver section, and a receiver IF to baseband section. The RF to IF receiver section includes a frequency translated bandpass filter (FTBPF), an LNA, and a mixing section. The FTBPF includes a switching network and a plurality of baseband impedances. The switching network is operable to couple the plurality of baseband impedances to the FEM interface in accordance with a plurality of phase-offset RF clock signals to RF bandpass filter the inbound RF signal. The LNA amplifies the filtered inbound RF signal and the mixing section mixes the amplified inbound RF signal with a local oscillation to produce an inbound IF signal. The receiver IF to baseband section converts the inbound IF signal into one or more inbound symbol streams.
摘要:
A SAW-less receiver includes an FEM interface module, an RF to IF receiver section, and a receiver IF to baseband section. The RF to IF receiver section includes inverter based LNA modules, a mixing module, and transimpedance amplifier modules. The inverter based LNA modules amplify inbound RF signal to produce a positive leg current RF signal and a negative leg current RF signal. The mixing module converts the positive and negative leg current RF signals into an in-phase (I) mixed current signal and a quadrature (Q) mixed current signal. The transimpedance amplifier modules convert the I mixed current signal into an I mixed voltage signal and the Q mixed current signal into a Q mixed voltage signal. The receiver IF to baseband section converts the I and Q mixed voltage signals into one or more inbound symbol streams.