Abstract: The present invention is an RF cancellation circuit located between the output of a power amplifier and downstream circuitry, such as a transmitting antenna. The RF cancellation circuit cancels reflections resulting from antenna impedance mismatches, thereby presenting a constant load impedance to the output of the power amplifier. The RF cancellation circuit extracts a portion of the reflected signal, phase-shifts by 180 degrees and amplifies the extracted portion of the reflected signal to create a cancellation signal, and then cancels the balance of the reflected signal by adding in the cancellation signal. Directional circuitry is used to process the reflected signals without interfering with normal transmitted signals. Presenting a constant load impedance to the output of the power amplifier helps facilitate compliance with total radiated power into load mismatch specifications.

Abstract: Pilot switch circuitry coupled across first and second terminals of a microelectromechanical system (MEMS) switch is provided to reduce or eliminate arcing between a cantilever contact and a terminal contact when the MEMS switch is opened or closed. The pilot switch circuitry establishes a common potential at the first and second terminals prior to, and preferably until, the cantilever contact and terminal contact come into contact with one another when the MEMS switch is closed. The pilot switch circuitry may also establish a common potential at the first and second terminals prior to, and preferably after, the cantilever contact and terminal contact separate from one another when the MEMS switch is opened.

Abstract: A system is provided for adjusting an output power of a multi-stage power amplifier by controlling a supply voltage provided to one or more output amplifier stages of the power amplifier using a switching DC—DC converter. In general, the system includes a power amplifier including an input amplifier stage and one or more output amplifier stages coupled in series with the input amplifier stage. The one or more output amplifier stages receive a variable supply voltage from switching DC—DC conversion circuitry. The switching DC—DC conversion circuitry provides the variable supply voltage based on an adjustable power control signal. By controlling the variable supply voltage provided to the one or more output stages, the switching DC—DC conversion circuitry controls an output power of the power amplifier based on the adjustable power control signal.

Abstract: An adaptive manufacturing process for a Film Bulk Acoustic Resonator (FBAR) tests the FBAR circuit during manufacturing to determine a resonant frequency thereof. Reactive tuning elements may be adjusted as needed depending on the testing to change the resonant frequency to a desired resonant frequency. In an exemplary embodiment, predetermined masks may be applied to modify the tuning elements.

Abstract: The present invention eliminates the need for complex impedance networks or parallel amplification stages for multi-mode mobile terminals. A wideband power amplifier is configured to amplify signals in different frequency bands corresponding to different operating modes. The supply voltage of the wideband power amplifier is adjusted in light of the load impedance of radiating circuitry to achieve a desired output power for the respective operating modes.

Abstract: An amplifier provides two or more selectively enabled amplifier segments allowing a source signal to be amplified with a selectable output power. A bias circuit responsive to a bias control signal enables selectable combinations of one or more amplifier segments, thus allowing selection of a desired output power. Selecting a desired output signal power via the bias control signal corresponds to selecting an overall amplifier quiescent current that decreases with decreasing output signal power. Thus, the amplifier permits a controlling system, such as a mobile terminal (e.g., cellular telephone) to amplify a transmit signal with a selectable transmit signal output power and corresponding level of amplifier quiescent power consumption. Preferably, each segment comprises one or more transistor amplification stages which, when enabled by the bias circuit, are biased to permit maximum power linear amplification for the transmit signal.

Abstract: An adaptive manufacturing process for a Film Bulk Acoustic Resonator (FBAR) tests the FBAR circuit during manufacturing to determine a resonant frequency thereof. Reactive tuning elements may be adjusted as needed depending on the testing to change the resonant frequency to a desired resonant frequency. In an exemplary embodiment, predetermined masks may be applied to modify the tuning elements.

Abstract: The present invention eliminates the need for complex impedance networks or parallel amplification stages for multi-mode mobile terminals. A wideband power amplifier is configured to amplify signals in different frequency bands corresponding to different operating modes. The supply voltage of the wideband power amplifier is adjusted in light of the load impedance of radiating circuitry to achieve a desired output power for the respective operating modes.

Abstract: An amplifier provides two or more selectively enabled amplifier segments allowing a source signal to be amplified with a selectable output power. A bias circuit responsive to a bias control signal enables selectable combinations of one or more amplifier segments, thus allowing selection of a desired output power. Selecting a desired output signal power via the bias control signal corresponds to selecting an overall amplifier quiescent current that decreases with decreasing output signal power. Thus, the amplifier permits a controlling system, such as a mobile terminal (e.g., cellular telephone) to amplify a transmit signal with a selectable transmit signal output power and corresponding level of amplifier quiescent power consumption. The amplifier is particularly advantageous for inclusion in systems designed for digital communications requiring variable transmit power levels, such as the digital cellular standard IS-95.

Abstract: The present invention relates to a process for implementing a base circuit design with configurable modifications to compensate for variations in component parameters due to material or processing characteristics. During the fabrication process, the base circuit is electrically tested to determine the characteristics of the base circuit given the materials and processes used to implement the circuit. Based on the testing, subsequent processing steps are used to modify the base circuit as necessary to compensate for variations in the circuit or component parameters due to the material or processing characteristics. Preferably, the base circuit includes hetero-junction bipolar transistors and the in-process testing is used to determine an associated beta value for the transistor. Based upon the determined beta value, the circuit is modified during processing to insure proper quiescent currents occur during normal operation given the beta of the transistor.

Abstract: A bias network uses resistive biasing, active biasing and current mirror biasing in combination to enhance RF power amplifier linearity and efficiency by forming a bias network that provides temperature compensation, minimizes current drain requirements for the Vbias source and reduces the level of RF linear amplifier quiescent current.

Abstract: A bias network uses resistive biasing, active biasing and current mirror biasing in combination to enhance RF power amplifier linearity and efficiency by forming a bias network that provides temperature compensation, minimizes current drain requirements for the Vbias source and reduces the level of RF linear amplifier quiescent current.

Abstract: A bias network uses resistive biasing, active biasing and current mirror biasing in combination to enhance RF power amplifier linearity and efficiency by forming a bias network that provides temperature compensation, minimizes current drain requirements for the Vbias source and reduces the level of RF linear amplifier quiescent current.

Abstract: A high efficiency multiple power level power amplifier has a PIN diode network that selectively associates an impedance transformation network with an interstage impedance matching network to maintain desired gain and linearity characteristics for the power amplifier at different output power levels. The PIN diode network in the off mode (high power), has a high breakdown voltage and high series resistance thereby reducing distortion components. The PIN diode network in the on mode (low power), has a low series resistance thereby reducing insertion losses.

Abstract: A bias network uses resistive biasing, active biasing and current mirror biasing in combination to enhance RF power amplifier linearity and efficiency by forming a bias network that provides temperature compensation, minimizes current drain requirements for the Vbias source and reduces the level of RF linear amplifier quiescent current.

Abstract: A bias network uses resistive biasing, active biasing and current mirror biasing in combination to enhance RF power amplifier linearity and efficiency by forming a bias network that provides temperature compensation, minimizes current drain requirements for the Vbias source and reduces the level of RF linear amplifier quiescent current.

Abstract: A bias network uses resistive biasing, active biasing and current mirror biasing in combination to enhance RF power amplifier linearity and efficiency by forming a bias network that provides temperature compensation, minimizes current drain requirements for the Vbias source and reduces the level of RF linear amplifier quiescent current.

Abstract: A bias network uses resistive biasing, active biasing and current mirror biasing in combination to enhance RF power amplifier linearity and efficiency by forming a bias network that provides temperature compensation, minimizes current drain requirements for the Vbias source and reduces the level of RF linear amplifier quiescent current.