Rf Micro Devices, Inc.

Victor E Steel

Jon D Jorgenson

David C Dening

Khoi Tam Vu

Michael R Kay

Edward T Spears

Ulrik Riis Madsen

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&#x2014;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&#x2014;DC conversion circuitry. The switching DC&#x2014;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&#x2014;DC conversion circuitry controls an output power of the power amplifier based on the adjustable power control signal.

Power amplifier control using a switching power supply

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.

Adaptive manufacturing for film bulk acoustic wave resonators

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.

Single output stage power amplification for multimode applications

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.

Segmented power amplifier and method of control

The present invention provides a dual mode amplifier capable of operating in a common (even) mode for one frequency band and a differential (odd) mode for a second frequency band. In the common mode, the amplifier provides two identical signals to a matching network, and in the differential mode, the amplifier provides two signals that are 180&deg; out-of-phase from one another to the matching network. The matching network is configured to maintain the same input and output impedance regardless of whether the amplifier is operating in the common or differential mode. Furthermore, the matching network is preferably configured to terminate second harmonics for each frequency band without affecting the fundamental tone for the other bands, even if the bands are an octave apart. Since the matching network operates on two signals, either common or differential signals, a power combining network is typically required to combine the two signals into a single signal for transmission.

Matching network for a dual mode RF amplifier

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.

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Oak Ridge, NC, United States of America

Victor E Steel