摘要:
A DC—DC converter includes a variable frequency oscillator, a control system and a power train. The DC—DC converter is well suited for use in a cell phone. The control system uses the output of the oscillator to control the power train. The oscillator varies its frequency as a function of a pseudo random number generator, thereby reducing electromagnetic interference caused by ripple in the output of the DC—DC converter.
摘要:
A circuit board having an embedded inductor and a process for making the circuit board is provided. In general, the process begins by providing a core structure including a dielectric core layer and a first metal layer on a top surface of the dielectric core layer. The first metal layer is etched to form first inductor windings. A material, such as an epoxy material, including magnetic filler material is deposited over the first inductor windings. Thereafter, a prepreg layer is placed over and attached to the material deposited over the first inductor windings to form the circuit board having the embedded inductor.
摘要:
A system and method are provided for efficiently amplifying a radio frequency signal. In general, the system includes power amplifier circuitry that efficiently amplifies an input signal under power back-off conditions. In one embodiment, the power amplifier circuitry has an efficiency of at least 30% at a 6 dB back-off point. In addition, DC-DC conversion circuitry operates to control a variable supply voltage provided to the power amplifier circuitry, thereby controlling an output power level, or average output power, of the power amplifier circuitry.
摘要:
A mobile terminal including a multi-phase DC-DC converter for controlling a supply voltage provided to a power amplifier in the transmit chain. In general, the multi-phase DC-DC converter includes a multi-phase converter control system and a multi-phase power train. The multi-phase converter control system generates a plurality of control signals based on a set-point voltage and a supply voltage at the output of the multi-phase DC-DC converter. The plurality of control signals are provided to the multi-phase control system which generates a plurality of currents each based on a corresponding one of the plurality of control signals. The plurality of currents charge an output capacitor such that an average voltage across the output capacitor is the desired supply voltage.
摘要:
Power control circuitry that is configurable as either a Low Dropout (LDO) voltage regulator or a switching DC—DC converter for controlling a variable supply voltage provided to a power amplifier of a mobile terminal is provided. The power control circuitry includes an output stage including first and second output transistors, an analog control system, and a digital control system. When in LDO voltage regulator mode, the analog control system provides an analog control signal to the first transistor based on an adjustable power control signal and a feedback signal indicative of the variable supply voltage, and the digital control system operates to disable the second output transistor. When in DC—DC converter mode, an output stage of the analog control system is disabled, and the digital control system provides binary control signals to the first and second transistors based on the adjustable power control signal and the feedback signal.
摘要:
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.
摘要:
A power amplifier circuit comprises a sensing circuit and a processing circuit adapted to detect voltage peaks in an output of a power amplifier. If the voltage peak is above a predetermined threshold level, the processing circuit acts to reduce bias provided to the power amplifier, thereby reducing the output levels.
摘要:
A patch antenna may be integrated into a mobile terminal by associating the patch antenna with a ground plane adapted to remove eddy currents and isolate the antenna from spurious electromagnetic signals. The patch antenna may comprise a kink. Together the patch antenna and ground plane form a surface on which other electrical components may be mounted, such as the transceiver circuitry of the mobile terminal.
摘要:
Apparatus and methods for electronic amplification are disclosed herein. In certain implementations, an amplifier is provided for amplifying a RF signal, and the amplifier includes a first transistor and a second transistor electrically connected in a Darlington configuration. The first and second transistors can be, for example, bipolar or field effect transistors and the first transistor can amplify an input signal and provide the amplified input signal to the second transistor. The first and second transistors are electrically connected to a power low node such as a ground node through first and second bias circuits, respectively. In certain implementations, the first transistor includes an inductor disposed in the path from the first transistor to the power low voltage. By including the inductor in the path from the first transistor to the ground node, the third order distortion of the amplifier can be improved.
摘要:
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.