Abstract: A method and apparatus if provided for shielding a capacitor structure formed in a semiconductor device. In a capacitor formed in an integrated circuit, one or more shields are disposed around layers of conductive strips to shield the capacitor. The shields confine the electric fields between the limits of the shields.

Abstract: A method and apparatus is provided for use in power amplifiers for reducing the peak voltage that transistors are subjected to. A power amplifier is provided with first and second switching devices and an inductor connected between the switching devices. The switching devices are driven such that the switching devices are turned on and off during the same time intervals. Differential RF power amplifiers are also provided with inductive networks coupled at various nodes of the power amplifiers. In some examples, techniques are used to stabilize differential power amplifiers by stabilizing common-mode feedback loops.

Abstract: A method and apparatus is used to provide DC stabilization and noise reduction in a multistage power amplifier. The invention uses various feedback techniques to stabilize DC levels, which helps to reduce noise. The invention also uses other techniques to reduce noise, and to reduce the noise transfer function in a power amplifier.

Abstract: A method and apparatus is provided for use in power amplifiers where multiple parallel power amplifiers provide various output power levels. By selectively enabling and disabling the parallel power amplifiers and combining their outputs, a desired output power can be realized, while choosing a combination of power amplifiers that provide a high efficiency.

Abstract: A method and apparatus is provided for use with a power amplifier to provide a regulated supply to the power amplifier. The invention uses a combination of voltage and current regulation to overcome the problems encountered in the prior art. In one example, voltage regulation is used at high power levels, while current regulation is used at low power levels.

Abstract: In a power amplifier, a serial bus interface is provided for sending and receiving information to other devices, such as a baseband controller. The power amplifier includes several control pins that can be used as a serial interface, or alternately, with a direct pin control interface. The power amplifier uses various techniques to address noise problems related to the use of a serial bus with a power amplifier.

Abstract: A method and apparatus provides techniques for electrically isolating switching devices in a stacked RF power amplifier, which prevents the switching devices from being subjected to high breakdown voltages. The isolation provided allows the power amplifier to be implemented on an integrated circuit.

Abstract: In a power amplifier, a serial bus interface is provided for sending and receiving information to other devices, such as a baseband controller. The power amplifier includes several control pins that can be used as a serial interface, or alternately, with a direct pin control interface. The serial bus interface can be used with digital power control techniques that provide various advantages over conventional power amplifiers.

Abstract: A method and apparatus is provided for dynamically changing the biasing conditions of a voltage regulator to overcome the problems caused by various conditions. The invention includes a detector and a bias control circuit for applying bias current to the voltage regulator to compensate for a detected condition.

Abstract: A method and apparatus provides an input structure for a power amplifier. In one example, the input structure has an input network and a predriver circuit to provide an input signal to the power amplifier. The input network includes a transformer for helping to maintain a constant input impedance. The predriver includes a limiting amplifier that provides isolation between the power amplifier and the RF input. A DC feedback circuit is used by the predriver that maintains the DC level of the inverters to a desired level.