Abstract: Certain aspects of the present disclosure provide an integrated impedance matching and filtering circuit. One example circuit generally includes an impedance matching circuit having a first inductor and a resonant circuit having a resonant frequency and comprising a second inductor magnetically coupled to the first inductor. The resonant circuit is configured to filter out the resonant frequency from the impedance matching circuit. In certain aspects, the resonant circuit may further include a capacitor. The second inductor may include a ring of metal having a gap, and the capacitor may comprise a dielectric material between ends of the ring surrounding the gap. For other aspects, the capacitor may be an integrated circuit element, having a fixed or variable value.

Abstract: A multi-mode multi-band power amplifier (PA) module is described. In an exemplary design, the PA module includes multiple power amplifiers, multiple matching circuits, and a set of switches. Each power amplifier provides power amplification for its input signal when selected. Each matching circuit provides impedance matching and filtering for its power amplifier and provides a respective output signal. The switches configure the power amplifiers to support multiple modes, with each mode being for a particular radio technology. Each power amplifier supports at least two modes. The PA module may further include a driver amplifier and an additional matching circuit. The driver amplifier amplifies an input signal and provides an amplified signal to the power amplifiers. The additional matching circuit combines the outputs of other matching circuits and provides an output signal with higher output power. The driver amplifier and the power amplifiers can support multiple output power levels.

Abstract: A compact integrated power amplifier is described herein. In an exemplary design, an apparatus includes (i) an integrated circuit (IC) die having at least one transistor for a power amplifier and (ii) an IC package having a load inductor for the power amplifier. The IC die is mounted on the IC package with the transistor(s) located over the load inductor. In an exemplary design, the IC die includes a transistor manifold that is placed over the load inductor on the IC package. The transistor(s) are fabricated in the transistor manifold, have a drain connection in the center of the transistor manifold, and have source connections on two sides of the transistor manifold. The IC die and the IC package may include one or more additional power amplifiers. The transistor(s) for each power amplifier may be located over the load inductor for that power amplifier.

Abstract: An impedance matching circuit with at least one tunable notch filter for a power amplifier is disclosed. The power amplifier amplifies an input radio frequency (RF) signal and provides an amplified RF signal. The impedance matching circuit performs output impedance matching for the power amplifier and includes at least one tunable notch filter. Each tunable notch filter has a notch that can be varied in frequency to provide better attenuation of an undesired signal. The at least one tunable notch filter attenuates at least one undesired signal in the amplified RF signal. The at least one tunable notch filter may include (i) a first tunable notch filter to attenuate a first undesired signal at a second harmonic of the amplified RF signal and/or (ii) a second tunable notch filter to attenuate a second undesired signal at a third harmonic of the amplified RF signal.

Abstract: An amplifier with integrated filter (e.g., an LNA) is described. In one design, the amplifier may include a gain stage, a filter stage, and a buffer stage. The gain stage may provide signal amplification for an input signal. The filter stage may provide filtering for the input signal. The buffer stage may buffer a filtered signal from the filter stage. The amplifier may further include a second filter stage and a second buffer stage. The second filter stage may provide additional filtering for the input signal. The second buffer stage may buffer a second filtered signal from the second filter stage. All of the stages may be stacked and coupled between a supply voltage and circuit ground. The filter stage(s) may implement an elliptical lowpass filter. Each filter stage may include an inductor and a capacitor coupled in parallel and forming a resonator tank to attenuate interfering signals.

Abstract: An integrated circuit is described. The integrated circuit includes an inductor that has a large empty area in the center of the inductor. The integrated circuit also includes additional circuitry. The additional circuitry is located within the large empty area in the center of the inductor. The additional circuitry may include a capacitor bank, transistors, electrostatic discharge (ESD) protection circuitry and other miscellaneous passive or active circuits.

Abstract: An impedance matching circuit with at least one tunable notch filter for a power amplifier is disclosed. The power amplifier amplifies an input radio frequency (RF) signal and provides an amplified RF signal. The impedance matching circuit performs output impedance matching for the power amplifier and includes at least one tunable notch filter. Each tunable notch filter has a notch that can be varied in frequency to provide better attenuation of an undesired signal. The at least one tunable notch filter attenuates at least one undesired signal in the amplified RF signal. The at least one tunable notch filter may include (i) a first tunable notch filter to attenuate a first undesired signal at a second harmonic of the amplified RF signal and/or (ii) a second tunable notch filter to attenuate a second undesired signal at a third harmonic of the amplified RF signal.

Abstract: An output circuit with integrated impedance matching, power combining, and filtering and suitable for use with power amplifiers and other circuits is described. In an exemplary design, an apparatus may include first and second circuits (e.g., power amplifiers) and an output circuit. The first circuit may provide a first single-ended signal and may have a first output impedance. The second circuit may provide a second single-ended signal and may have a second output impedance. The output circuit may include (i) first and second matching circuits that perform output impedance matching and filtering for the first and second circuits, (ii) a combiner (e.g., a summing node) that combines the first and second single-ended signals to obtain a combined single-ended signal, (iii) a third matching circuit that performs impedance matching and filtering for the combined single-ended signal, and (iv) switches to route the single-ended signals to different outputs.

Abstract: An amplifier with integrated filter (e.g., an LNA) is described. In one design, the amplifier may include a gain stage, a filter stage, and a buffer stage. The gain stage may provide signal amplification for an input signal. The filter stage may provide filtering for the input signal. The buffer stage may buffer a filtered signal from the filter stage. The amplifier may further include a second filter stage and a second buffer stage. The second filter stage may provide additional filtering for the input signal. The second buffer stage may buffer a second filtered signal from the second filter stage. All of the stages may be stacked and coupled between a supply voltage and circuit ground. The filter stage(s) may implement an elliptical lowpass filter. Each filter stage may include an inductor and a capacitor coupled in parallel and forming a resonator tank to attenuate interfering signals.

Abstract: An amplifier with integrated filter (e.g., an LNA) is described. In one design, the amplifier may include a gain stage, a filter stage, and a buffer stage. The gain stage may provide signal amplification for an input signal. The filter stage may provide filtering for the input signal. The buffer stage may buffer a filtered signal from the filter stage. The amplifier may further include a second filter stage and a second buffer stage. The second filter stage may provide additional filtering for the input signal. The second buffer stage may buffer a second filtered signal from the second filter stage. All of the stages may be stacked and coupled between a supply voltage and circuit ground. The filter stage(s) may implement an elliptical lowpass filter. Each filter stage may include an inductor and a capacitor coupled in parallel and forming a resonator tank to attenuate interfering signals.

Abstract: An integrated circuit is described. The integrated circuit includes an inductor that has a large empty area in the center of the inductor. The integrated circuit also includes additional circuitry. The additional circuitry is located within the large empty area in the center of the inductor. The additional circuitry may include a capacitor bank, transistors, electrostatic discharge (ESD) protection circuitry and other miscellaneous passive or active circuits.

Abstract: A compact integrated power amplifier is described herein. In an exemplary design, an apparatus includes (i) an integrated circuit (IC) die having at least one transistor for a power amplifier and (ii) an IC package having a load inductor for the power amplifier. The IC die is mounted on the IC package with the transistor(s) located over the load inductor. In an exemplary design, the IC die includes a transistor manifold that is placed over the load inductor on the IC package. The transistor(s) are fabricated in the transistor manifold, have a drain connection in the center of the transistor manifold, and have source connections on two sides of the transistor manifold. The IC die and the IC package may include one or more additional power amplifiers. The transistor(s) for each power amplifier may be located over the load inductor for that power amplifier.

Abstract: An output circuit with integrated impedance matching, power combining, and filtering and suitable for use with power amplifiers and other circuits is described. In an exemplary design, an apparatus may include first and second circuits (e.g., power amplifiers) and an output circuit. The first circuit may provide a first single-ended signal and may have a first output impedance. The second circuit may provide a second single-ended signal and may have a second output impedance. The output circuit may include (i) first and second matching circuits that perform output impedance matching and filtering for the first and second circuits, (ii) a combiner (e.g., a summing node) that combines the first and second single-ended signals to obtain a combined single-ended signal, (iii) a third matching circuit that performs impedance matching and filtering for the combined single-ended signal, and (iv) switches to route the single-ended signals to different outputs.

Abstract: A multi-mode multi-band power amplifier (PA) module is described. In an exemplary design, the PA module includes multiple power amplifiers, multiple matching circuits, and a set of switches. Each power amplifier provides power amplification for its input signal when selected. Each matching circuit provides impedance matching and filtering for its power amplifier and provides a respective output signal. The switches configure the power amplifiers to support multiple modes, with each mode being for a particular radio technology. Each power amplifier supports at least two modes. The PA module may further include a driver amplifier and an additional matching circuit. The driver amplifier amplifies an input signal and provides an amplified signal to the power amplifiers. The additional matching circuit combines the outputs of other matching circuits and provides an output signal with higher output power. The driver amplifier and the power amplifiers can support multiple output power levels.

Abstract: An amplifier with integrated filter (e.g., an LNA) is described. In one design, the amplifier may include a gain stage, a filter stage, and a buffer stage. The gain stage may provide signal amplification for an input signal. The filter stage may provide filtering for the input signal. The buffer stage may buffer a filtered signal from the filter stage. The amplifier may further include a second filter stage and a second buffer stage. The second filter stage may provide additional filtering for the input signal. The second buffer stage may buffer a second filtered signal from the second filter stage. All of the stages may be stacked and coupled between a supply voltage and circuit ground. The filter stage(s) may implement an elliptical lowpass filter. Each filter stage may include an inductor and a capacitor coupled in parallel and forming a resonator tank to attenuate interfering signals.

Abstract: The balanced, retractable dipole antenna comprises a first radiator element that is selectively extendable from, and retractable into, a mobile phone casing, a second radiator element, and a counterpoise that is electrically isolated from a printed wire board (PWB) of a mobile phone. The balanced, retractable dipole antenna further comprises a signal balancing means coupled between a signal source and at least the second radiator element and counterpoise to generate first and second signals, respectively. The first and second signals are substantially equal in magnitude but out of phase by 180 degrees. When the first radiator is extended, the first signal is transferred to the first and second radiator elements, and the second signal is transferred to the counterpoise. When the first radiator element is retracted, the first signal is transferred to the second radiator, while the second signal is transferred to the counterpoise and the first radiator element.

Abstract: A balanced dipole antenna for a mobile phone comprises a radiator element and a counterpoise, both formed of a conducting material. The counterpoise is electrically isolated from the ground plane of a printed wire board (PWB) of the mobile phone. A matching network, for example, a balun, provides balanced current to the dipole antenna, resulting in a symmetric radiation pattern. The balanced dipole antenna allows superior performance over conventional antennas found in mobile phones today by enabling a user of a mobile phone to communicate effectively and uniformly in all directions, that is, 360 degrees.