摘要:
An integrated automatic IIP2 calibration architecture for wireless transceivers is disclosed. The architecture enables a wireless transceiver to generate a test radio frequency (RF) signal having a second order tone with minimal additional circuitry. In particular, the test RF signal is generated using a combination of native transceiver circuits and test adaptor circuits. Native transceiver circuits are those circuits implemented on the transceiver chip for executing native transceiver functions during normal operation, which can be used for generating the test (RF) signal. Test adaptor circuits are added to the transceiver chip, more specifically to the native circuits, for enabling the native circuits to generate the test RF signal in a self-test mode of operation. Circuits for implementing a particular IIP2 minimizing scheme can be included on the transceiver chip for automatic IIP2 calibration during the self-test mode of operation.
摘要:
A power ramping circuit for use in the transmit path of a radio frequency (RF) circuit. The power ramping circuit includes parallel connected transistors used as logarithmic resistor attenuators for adjusting current to a mixer circuit in the transmit path. The parallel connected transistors can be sized differently, and are sequentially turned off to gradually increase the current provided to the mixer circuit. A ramp control circuit controls the parallel connected transistors in response to either an analog signal or a digital signal.
摘要:
The invention is directed at a hybrid modulation apparatus which combines a polar modulation circuit and a linear modulation circuit. The hybrid apparatus allows a communications device to function as a polar or a linear modulation circuit with less components as the output of the linear modulation circuit is an input of the polar modulation circuit.
摘要:
A digital linear transmitter for digital to analog conversion of a radio frequency signal. The transmitter includes a delta sigma (ΔΣ) digital to analog converter (DAC) and a weighted signal digital to analog converter in the transmit path of a wireless device to reduce reliance on relatively large analog components. The ΔΣ DAC converts the lowest significant bits of the oversampled signal while the weighted signal digital to analog converter converts the highest significant bits of the oversampled signal. The transmitter core includes components for providing an oversampled modulated digital signal which is then subjected to first order filtering of the oversampled signal prior to generating a corresponding analog signal. The apparatus and method reduces analog components and increases digital components in transmitter core architecture of wireless RF devices.
摘要:
A transmitter architecture having a single signal path or hardware to cover WCDMA/EDGE/GSM applications, and requires no SAW at the transmitter outputs. The transmitter architecture allows for a transmit convergence feature. A passive mixer with unique driver and furthermore using native devices available from the CMOS process for the mixer cores enables low voltage and low power design, low output noise and high linearity. A digital variable gain amplifier has the capability to cover wide output dynamic range operated from low supply voltage and interfaced digitally with the baseband circuit without DAC. A single transformer is used to combine the outputs from the WCDMA/EDGE and GSM drivers and subsequently convert the differential signal paths into a single-ended signal. RF switches are used to divert the output from the transformer to different bands and applications.
摘要:
A closed loop power output calibration system for variable power output wireless devices. The wireless device includes a wireless transceiver having a transmit core coupled to a discrete power amplifier. Power detection circuitry formed in the wireless transceiver provides a detected power level of the power amplifier, and a reference power level, both of which are converted to digital signals using existing I and Q signal analog to digital converters in the receiver core. The digital signals are processed to cancel power distortion and temperature effects to provide a resulting power feedback signal. Corrective control signals are generated in response to the power feedback signal relative to a desired power output level. The gain in the transmit core is then adjusted in response to the corrective control signals such that the power amplifier outputs the target output power level.
摘要:
A transmitter architecture having a single signal path or hardware to cover WCDMA/EDGE/GSM applications, and requires no SAW at the transmitter outputs. The transmitter architecture allows for a transmit convergence feature. A passive mixer with unique driver and furthermore using native devices available from the CMOS process for the mixer cores enables low voltage and low power design, low output noise and high linearity. A digital variable gain amplifier has the capability to cover wide output dynamic range operated from low supply voltage and interfaced digitally with the baseband circuit without DAC. A single transformer is used to combine the outputs from the WCDMA/EDGE and GSM drivers and subsequently convert the differential signal paths into a single-ended signal. RF switches are used to divert the output from the transformer to different bands and applications.
摘要:
An integrated automatic IIP2 calibration architecture for wireless transceivers is disclosed. The architecture enables a wireless transceiver to generate a test radio frequency (RF) signal having a second order tone with minimal additional circuitry. In particular, the test RF signal is generated using a combination of native transceiver circuits and test adaptor circuits. Native transceiver circuits are those circuits implemented on the transceiver chip for executing native transceiver functions during normal operation, which can be used for generating the test (RF) signal. Test adaptor circuits are added to the transceiver chip, more specifically to the native circuits, for enabling the native circuits to generate the test RF signal in a self-test mode of operation. Circuits for implementing a particular IIP2 minimizing scheme can be included on the transceiver chip for automatic IIP2 calibration during the self-test mode of operation.
摘要:
A digital linear transmitter for digital to analog conversion of a radio frequency signal. The transmitter includes a delta sigma (ΔΣ) digital to analog converter (DAC) and a weighted signal digital to analog converter in the transmit path of a wireless device to reduce reliance on relatively large analog components. The ΔΣ DAC converts the lowest significant bits of the oversampled signal while the weighted signal digital to analog converter converts the highest significant bits of the oversampled signal. The transmitter core includes components for providing an oversampled modulated digital signal which is then subjected to first order filtering of the oversampled signal prior to generating a corresponding analog signal. The apparatus and method reduces analog components and increases digital components in transmitter core architecture of wireless RF devices.
摘要:
A closed loop power output calibration system for variable power output wireless devices. The wireless device includes a wireless transceiver having a transmit core coupled to a discrete power amplifier. Power detection circuitry formed in the wireless transceiver provides a detected power level of the power amplifier, and a reference power level, both of which are converted to digital signals using existing I and Q signal analog to digital converters in the receiver core. The digital signals are processed to cancel power distortion and temperature effects to provide a resulting power feedback signal. Corrective control signals are generated in response to the power feedback signal relative to a desired power output level. The gain in the transmit core is then adjusted in response to the corrective control signals such that the power amplifier outputs the target output power level.