Abstract: Tunable notch filters and control loop systems and methods can include a tunable notch filter providing a stop band, a sensing circuit in communication with the tunable notch filter and adapted to determine a phase change between a reference signal and a signal reflected from the tunable notch filter, and a control loop in communication with the tunable notch filter and the sensing circuit, the control loop being operable to adjust the tunable notch filter to modify the phase change.

Abstract: Methods for tuning a tunable matching network can involve comparing a source impedance of a source to a real part of a load impedance of a load. Depending on characteristics of the network, capacitances of one or more tunable capacitors can be set to correspond to device boundary parameters, and capacitances of remaining tunable capacitors can be set based on a predetermined relationship between the parameters of the capacitors, the source, the load, and other components. From these initially determined values, the capacitance value of one or more of the capacitors can be adjusted to fall within device boundary conditions and achieve a perfect or at least best match tuning configuration.

Abstract: Tunable notch filters and control loop systems and methods can include a tunable notch filter providing a stop band, a sensing circuit in communication with the tunable notch filter and adapted to determine a phase change between a reference signal and a signal reflected from the tunable notch filter, and a control loop in communication with the tunable notch filter and the sensing circuit, the control loop being operable to adjust the tunable notch filter to modify the phase change.

Abstract: Methods for tuning a tunable matching network can involve comparing a source impedance of a source to a real part of a load impedance of a load. Depending on characteristics of the network, capacitances of one or more tunable capacitors can be set to correspond to device boundary parameters, and capacitances of remaining tunable capacitors can be set based on a predetermined relationship between the parameters of the capacitors, the source, the load, and other components. From these initially determined values, the capacitance value of one or more of the capacitors can be adjusted to fall within device boundary conditions and achieve a perfect or at least best match tuning configuration.

Abstract: Disclosed is a method to operate a RF transmitter, and an RF transmitter constructed to operate in accordance with the method. The method includes determining a transmitter output power and varying a level of a signal at a transmitter phase modulator according to the transmitter output power so as to increase the level of the signal as the transmitter output power increases and to decrease the level of the signal as the transmitter output power decreases. In the preferred embodiment the method further includes adjusting the current consumption of a plurality of components of an RF transmitter chain in accordance with at least one of the level of the signal and the gain of the stage.

Abstract: A signal reception method including method and apparatus for receiving a signal, down converting the received signal through multi-tone down conversion to form an intermediate signal, and decoding the intermediate signal to extract data. In an embodiment, the received signal may include multiple transmission bands of a multi-code (MC)-CDMA signal, each of which occupies a different spectrum. Each of the transmission bands also includes an information channel signal. When the received MC-CDMA signal is down converted through multi-tone down conversion, the intermediate signal is formed. The intermediate signal includes a common spectrum that includes an information channel from a plurality of transmission bands. When the intermediate signal is decoded, data from a plurality of information channel bands is extracted. The method and apparatus may be implemented in a multi-mode MC-CDMA/CDMA receiver.

Abstract: An AGC system in a receiver adjusts the front-end gain not only based on the received sector power level, but also based on the strength of the present interference. When there is no presence of strong electromagnetic interference, the front-end gain of the receiver is set at a high level so that the receiver is maintained at a high sensitivity level. The receiver is operable at a normal current mode and a current saving mode. The receiver is set to run at the normal mode when the received sector power is lower than a certain predetermined level or when a strong interference is present.

Abstract: An integrated circuit includes an RF receiver has a direct-conversion down-converter and demodulator architecture with an integrated low noise amplifier (LNA) for operation in a frequency band of interest (cellular) and provisions for an off-chip LNA for operation in a second (higher) frequency band of interest (such as PCS). A baseband processor includes high-dynamic variable gain amplifiers and 7th-order elliptic low-pass filters. The IC also includes a 4 GHz PLL frequency synthesizer and a three wire series interface to external digital baseband circuits, such as a digital signal processor.

Abstract: Disclosed is a method to operate a RF transmitter, and an RF transmitter constructed to operate in accordance with the method. The method includes determining a transmitter output power and varying a level of a signal at a transmitter phase modulator according to the transmitter output power so as to increase the level of the signal as the transmitter output power increases and to decrease the level of the signal as the transmitter output power decreases. In the preferred embodiment the method further includes adjusting the current consumption of a plurality of components of an RF transmitter chain in accordance with at least one of the level of the signal and the gain of the stage.

Abstract: Apparatus, and an associated method, for a direct conversion receiver by which to selectably increase the sensitivity of the receiver. The direct conversion receiver includes a baseband amplifier positioned in front of a baseband filter, and coupled to receive a direct-converted baseband signal. The gain at which the baseband amplifier amplifies the signal provided thereto is selected, in combination with gains applied to other amplification elements of the direct conversion receiver to distribute the gain across the receive chain. When a signal received at the receiver includes a large interfering signal component, the gain of the baseband amplifier is reduced to lessen the possibility that the amplified signal become saturated. A gain controller controls the gain of the amplification elements.

Abstract: Apparatus, and an associated method, for a direct conversion receiver by which to selectably increase the sensitivity of the receiver. The direct conversion receiver includes a baseband amplifier positioned in front of a baseband filter, and coupled to receive a direct-converted baseband signal. The gain at which the baseband amplifier amplifies the signal provided thereto is selected, in combination with gains applied to other amplification elements of the direct conversion receiver to distribute the gain across the receive chain. When a signal received at the receiver includes a large interfering signal component, the gain of the baseband amplifier is reduced to lessen the possibility that the amplified signal become saturated. A gain controller controls the gain of the amplification elements.

Abstract: An RF signal reception method includes mixing a received signal and a local oscillator signal to form a down converted signal. The down converted signal formed from the received signal is a modulated non-zero low frequency carrier referred to as a low frequency carrier desired signal. The low frequency carrier desired signal is extracted from undesired signals and interferers by using low or band-pass filters and the resulting signal is AC coupled to low frequency amplifiers for amplification. A digital representation of the low frequency carrier desired signal is then formed by digitally sampling at an analog-to-digital converter. The digitized desired signal may be further processed by digital signal processing devices for obtaining voice and/or data messages.