Abstract:
A closed power control feedback loop system allows a single portable transceiver architecture to be used for systems in which a transmit signal including both a phase modulated (PM) component and an amplitude modulated (AM) component are supplied to a power amplifier and in systems in which the transmit signal has only a PM component supplied to a power amplifier. By injecting the inverse of the AM portion of the desired transmit signal into the closed power control feedback loop, the feedback loop will not cancel the AM portion of the signal, thus allowing a system where both a PM component and an AM component of the transmit signal are present at the output of the power amplifier to function using a closed power control feedback loop.
Abstract:
A multi-band transceiver having a receiver portion and a transmitter portion, wherein the receiver portion includes a direct conversion receiver system for directly downconverting a signal to baseband frequencies. The direct conversion receiver system includes a frequency translator having first and second inputs and an output. A first signal at a first frequency is applied to the first input. A second signal having a second frequency is applied to the second input. The first frequency is preferably an nth order subharmonic of the second frequency, wherein n is an integer greater than 1. A low pass filter is integral with or inherent to the first input, and a high pass filter is integral with or inherent to the second input. The corner frequencies of both the low pass and high pass filters is above the first frequency and below the second frequency.
Abstract:
A system for controlling a power amplifier using a dual feedback translation loop uses the output of the translation loop during a first time period where a power amplifier has insufficient power to lock the loop and uses the output of the power amplifier to lock the translation loop only after the power amplifier provides sufficient power. By using a first feedback loop taken from the output of the translation loop and a second feedback loop taken from the output of the power amplifier, the translation loop can lock to the output of the translation loop until the power output of the power amplifier is sufficient to lock the translation loop. A pair of phase detectors and corresponding charge pumps associated with each of the feedback loops provides a smooth switching function while transitioning from the first loop to the second loop.
Abstract:
Systems and methods are provided for detecting forward power sent to an antenna and reflected power reflected back from the antenna. Embodiments of the present invention provide systems and methods for measuring forward and reflected power and controlling the amount of power supplied to the antenna responsive to these measurements. Embodiments of the present invention enable the power sent to the antenna to be dynamically altered when antenna impendence changes (e.g., when the antenna gets too close to another object).
Abstract:
A system for transmitting and receiving data is provided. The system includes a direct-conversion receiver that receives a signal modulated on a carrier frequency signal. The direct-conversion receiver includes one or more subharmonic local oscillator mixers. A local oscillator is connected to the direct conversion receiver, and generates a signal having a frequency equal to a subharmonic of the carrier frequency signal. A transmitter is connected to the local oscillator, which uses the local oscillator signal to transmit outgoing data.
Abstract:
A controller enables the integration of a DC-DC converter in an amplitude modulation power control loop in a mobile handset. The controller includes an input conditioner and an event sensor. The input conditioner uses a peak detector to track the output of a regulator and responds to available baseband input signals. The event sensor controls a switch that connects the DC-DC converter to a battery in response to a bypass event. The controller bypasses the DC-DC-converter when a transmitter is not enabled. The DC-DC converter is enabled prior to a transmission burst. A target voltage is determined from a series of detected peak voltages from the output of the regulator. The controller commands the DC-DC converter to transition to the target voltage until the end of a transmission burst.
Abstract:
A system for saturation detection, correction and recovery in a power amplifier includes a power amplifier, a closed power control loop configured to develop a power control signal (VPC), and power control circuitry configured to reduce the power control signal if the power amplifier is operating in a saturation mode.
Abstract:
A supply voltage controlled power amplifier includes a power amplifier, a closed power control loop configured to generate a power control signal, and a voltage regulator coupled to the power control loop, the voltage regulator including a first regulator stage, a second regulator stage, and a peak detector, wherein an output of the second regulator stage is applied as a feedback signal to the first regulator stage and wherein an output of the first regulator stage is decreased to a level consistent with an output of the power amplifier and an additional operating buffer amount.
Abstract:
A variable gain frequency multiplier comprises a multiplier circuit and a control circuit configured to receive a power control signal, the power control signal being proportional to a power output signal.
Abstract:
A low noise mixer comprises a first mixer core configured to receive a radio frequency (RF) input signal having an RF frequency, and a first local oscillator signal, wherein the first local oscillator signal is at a frequency that is nominally twice the frequency of the RF frequency, the first mixer core configured to switch the RF input signal to at least one secondary mixer core at a frequency that coincides with the frequency of the first local oscillator signal, the at least one secondary mixer core configured to receive the switched RF input signal and a second local oscillator signal, where the second local oscillator signal is at the same nominal frequency as the RF input signal, and wherein switching the RF input signal at the frequency of the first local oscillator signal substantially eliminates flicker noise associated with the down-conversion process.