Abstract: A system for saturation detection and compensation in a power amplifier includes a power amplifier, a closed power control loop configured to develop a power control signal (VPC), a comparator configured to receive the power control signal and a reference signal, the comparator also configured to determine whether the power amplifier is operating in a saturation mode, and power control circuitry configured to reduce the power control signal if the power amplifier is operating in a saturation mode.

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 system for generating local oscillator (LO) signals for a quadrature mixer includes an oscillator configured to provide a reference frequency signal, at least one frequency divider configured to divide the reference frequency signal into three offset phase signals, a first summing circuit configured to generate two nominal 90 degree offset phase signals from the three offset phase signals, and a second summing circuit configured to generate at least two amplitude-corrected 90 degree offset-phase quadrature signals.

Abstract: A system for a fast, closed power control loop that quickly adjusts the output power of a power amplifier in a non-constant amplitude modulation format. Embodiments of the invention allow fast and precise closed loop power control in a communication system that has a transmit signal that includes a phase modulated component and an amplitude modulated signal component. By detecting the level of the transmit signal before and after the power amplifier, the invention ignores changes in the amplitude of the transmit signal, resulting in an accurate measure of the power amplifier gain. The difference between the level of the transmit signal before and after the power amplifier provides a signal that represents the gain of the power amplifier. The gain signal is compared with a reference signal to develop an error signal. The error signal is used to control the output of the power amplifier.

Abstract: A system for compensating gain control variations in a power amplifier comprises a power control element configured to receive a power control signal and an instantaneous envelope power reference signal, an adder configured to combine the power control signal and the instantaneous envelope power reference signal to obtain a modified power level signal, and a mapping function configured to receive the modified power level signal and configured to alter a control input to a variable gain amplifier, the variable gain amplifier controlling an adjustable input to the power amplifier.

Abstract: A single continuous closed-loop power control feedback system provides seamless power control for a power amplifier and also enables an AM signal to be injected into the power amplifier through the power amplifiers' control port. The AM signal is developed by an I/Q modulator and supplied to a comparator located in the power control loop. By using leakage from the power amplifier as feedback to a phase locked loop during initial power amplifier power ramp-up, the single continuous closed-loop power control system provides continuous feedback to the phase locked loop during the entire power amplification ramp-up period and eliminates the need for multiple feedback loops.

Abstract: A single chip GSM/EDGE transceiver comprises a fully differential receive chain, a subharmonic mixer in the receive chain, the subharmonic mixer configured to receive a radio frequency (RF) input signal and a local oscillator (LO) signal that is phase-shifted by a nominal 45 degrees, and a synthesizer having a voltage controlled oscillator and having at least one frequency divider to generate desired transmit and receive LO signals. The transceiver also comprises a transmitter having a closed power control loop, and a harmonic rejection modulator, the use thereof made possible by a frequency plan designed to allow the synthesizer to develop the transmit and receive LO signals without a frequency multiplier.

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 differential radio frequency (RF) receiver includes a fully differential direct conversion receive chain, a subharmonic mixer in the receive chain, the subharmonic mixer configured to receive a differential radio frequency (RF) input signal and a local oscillator (LO) signal that is phase-shifted by a nominal 45 degrees, and a synthesizer having a voltage controlled oscillator and having at least one frequency divider to generate desired receive LO signals.

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.

Abstract: A closed loop power control system for a radio frequency (RF) transmitter comprises a first variable gain element located in a power control loop and configured to receive a power level signal and an inverse representation of a power control signal, a second variable gain element located in the power control loop and configured to receive an error signal and the power control signal, and a third variable gain element configured to receive an amplitude modulated (AM) signal and the power control signal, the third variable gain element having a gain characteristic configured to operate to reduce the gain applied to the AM signal when the power control signal falls below a minimum predetermined value, and to provide the AM signal as a reference signal.

Abstract: A supply voltage controlled power amplifier that comprises a power amplifier, a closed power control feedback loop configured to generate a power control signal, and a dual voltage regulator coupled to the power control feedback loop, the dual voltage regulator comprising a first regulator stage and a second regulator stage, wherein the closed power control loop minimizes noise generated by the first regulator stage.

Abstract: A single continuous closed-loop power control feedback system provides seamless power control for a power amplifier and also enables an AM signal to be injected into the power amplifier through the power amplifiers' control port. The AM signal is developed by an I/Q modulator and supplied to a comparator located in the power control loop. By using leakage from the power amplifier as feedback to a phase locked loop during initial power amplifier power ramp-up, the single continuous closed-loop power control system provides continuous feedback to the phase locked loop during the entire power amplification ramp-up period and eliminates the need for multiple feedback loops.

Abstract: A mirror translation loop upconverter that is capable of upconverting both constant envelope and non-constant envelope modulation formats is disclosed. Embodiments of the invention provide the ability to upconvert a transmit signal that includes only a phase-modulated component, only an amplitude-modulated component, or both a phase-modulated component and an amplitude-modulated component. If the transmit signal includes both a phase-modulated signal component and an amplitude-modulated signal component, the phase-modulated signal component and the amplitude-modulated signal component are supplied to a pair of phase shifters. The phase shifters alter the phase of the phase-modulated signal by an amount related to the amplitude of the amplitude-modulated signal. The phase shifters oppositely alter the phase of the phase-modulated signal, and therefore supply complementary phase versions of the phase-modulated signal.

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 translation loop signal upconverter is disclosed. Embodiments of the invention minimize nth order harmonics and spurious tones in the radio frequency output spectrum of a portable transceiver. In one embodiment, the invention is a signal upconverter, comprising a modulator configured to develop a modulated intermediate frequency (IF) signal at a fundamental frequency, the modulated IF signal also including a plurality of nth order components, a synchronous oscillator configured to receive the modulated IF signal, the synchronous oscillator also configured to operate at the fundamental frequency of the modulated IF signal, thereby providing an IF signal substantially free of the nth order components, and a translation loop having a phase locked loop, the translation loop configured to receive the IF signal output of the synchronous oscillator, and supply a radio frequency (RF) output signal to a power amplifier.

Abstract: A linear power control loop for a power amplifier is disclosed. Embodiments of the invention linearly control the power amplifier output, prevent the power amplifier from failure induced by excessive supply current by reducing power amplifier bias current, and provide a mechanism to detect whether the power amplifier is operating in a saturation condition.

Abstract: A method for a closed power control feedback loop 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 single continuous closed-loop power control feedback system provides seamless power control for a power amplifier and also enables an AM signal to be injected into the power amplifier through the power amplifiers' control port. The AM signal is developed by an I/Q modulator and supplied to a comparator located in the power control loop. By using leakage from the power amplifier as feedback to a phase locked loop during initial power amplifier power ramp-up, the single continuous closed-loop power control system provides continuous feedback to the phase locked loop during the entire power amplification ramp-up period and eliminates the need for multiple feedback loops.

Abstract: A linear power control loop for a power amplifier is disclosed. Embodiments of the invention linearly control the power amplifier output, prevent the power amplifier from failure induced by excessive supply current by reducing power amplifier bias current, and provide a mechanism to detect whether the power amplifier is operating in a saturation condition.