The invention relates to a broadband high power amplifier that comprises a signal input adapted to receive an input signal, at least one amplifier stage adapted to amplify the received input signal, a signal output adapted to output the signal amplified by the at least one amplifier stage as an output signal, a monitoring unit adapted to monitor signal characteristics of the input signal and the output signal and a control unit adapted to operate the at least one amplifier stage at an optimal operating point depending on the current signal characteristics monitored by said monitoring unit.

Generally, in accordance with the various illustrative embodiments disclosed herein, a wideband amplifier includes a direct-current (DC) differential amplifier, an alternating-current (AC) differential amplifier, and a signal combiner circuit. The frequency response of each of the DC differential amplifier and the AC amplifier can be selectively modified by placing the wideband amplifier in one of at least three different operational configurations. The three different operational configurations can be broadly interpreted as a wideband operational configuration, a low-pass operational configuration, and a high-pass operational configuration. The signal combiner circuit operates as a low-pass filter connected to an output terminal of the DC differential amplifier and as a high-pass filter connected to an output terminal of the AC differential amplifier.

A circuit with a pseudo class-AB structure is shown. The circuit has an output stage, a first capacitor, and a first impedance component. The output stage has a first PMOS (p-type Metal-Oxide-Semiconductor Field-Effect Transistor) and a first NMOS (n-type MOSFET). The first connection node between the drain terminal of the first PMOS and the drain terminal of the first NMOS is coupled to the first output terminal of the circuit. The first capacitor is coupled between the gate terminal of the first PMOS and the gate terminal of the first NMOS. The first impedance component is coupled in parallel with the first capacitor between the gate terminal of the first PMOS and the gate terminal of the first NMOS.

Low-load-modulation, broadband power amplifiers and method of use are described. The amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the fully-on and fully backed-off states of the amplifier. With lower load modulation, the power amplifiers described herein exhibit better power-handling capability and RF fractional bandwidth as compared to conventional amplifiers.

A receiver can include a first set of one or more amplifier stages configured to amplify input signals in a plurality of communication bands. The receiver can further include a second and third set of one or more amplifier stages. The second set of one or more amplifier stages can be configured to selectively receive the input signals in the plurality of communication bands amplified by the first set of one or more amplifier stages and to amplify one or more input signals in a first one of the plurality of communication bands. Alternatively, the third set of one or more amplifier stages can be configured to selectively receive the input signals in the plurality of communication bands amplified by the first set of one or more amplifier stages and to amplify one or more input signals in a second one of the plurality of communication bands. A first set of one or more mixers can be configured to receive the input signals in the first communication band amplified by the second set of one or more amplifier stages, to receive one or more local oscillator signals for the first communication band, and to generate a baseband signal from a frequency difference of the signal of the first communication band and the one or more local oscillator signals for the first communication band. A second set of one or more mixers can be configured to receive the input signal in the second communication band amplified by the third set of one or more amplifier stages, to receive one or more local oscillator signals for the second communication band, and to generate a baseband signal of the second communication band.

An operational amplifier includes a first amplifying unit, a second amplifying unit, a current source, a first compensation capacitor, and a second compensation capacitor. The first amplifying unit includes a first input transistor, a second input transistor, a third input transistor, and a fourth input transistor. The second amplifying unit includes a fifth input transistor, a sixth input transistor, a seventh input transistor, and an eighth input transistor. One end of the first compensation capacitor is coupled to a drain of the seventh input transistor, and the other end of the first compensation capacitor is coupled to a gate of the eighth input transistor. One end of the second compensation capacitor is coupled to a drain of the eighth input transistor, and the other end of the second compensation capacitor is coupled to a gate of the seventh input transistor.

Methods, circuits, and apparatuses are disclosed that provide a buffer amplifier with lower output noise by narrow banding the amplifier. To reinvigorate the speed of the narrow-banded amplifier, a boost-on signal is initiated. The boost-on signal dynamically and rapidly injects a substantial current into the amplifier's bias current network to speed up its slew rate, when the amplifier's inputs get unbalanced when being subjected to a large transient differential input signal. Subsequently, after the amplifier regulate itself and as the amplifier's inputs approach substantial balance, a boost-off signal dynamically injects a slow and decaying current (that converges to the level of static steady-state bias current) into amplifier's bias circuitry, instead of turning off the boost current rapidly, which improves the amplifier's settling time.

According to one embodiment, a compact broadband radio frequency (RF) receiver circuit includes a low noise amplifier which includes a first amplifier stage, a second amplifier stage, an inter-stage network including a higher order filter network, where the inter-stage network is coupled between the first amplifier stage and the second amplifier stage, and a double resonance transformer network coupled to an output of the second amplifier stage. The RF receiver circuit includes a low pass filter and a mixer circuit coupled between the low noise amplifier and the low pass filter.

A wideband power amplifier (PA) linearization technique is proposed. A current interpolation technique is proposed to linearize power amplifiers over a wide bandwidth. The wideband power amplifier linearization technique employs a novel transconductance Gm linearizer using a current interpolation technique that achieves improvement in the third order intermodulation over wide bandwidth for a sub-micron CMOS differential power amplifier. By using a small amount of compensating bias into an opposite phase differential pair, linearization over wide bandwidth is achieved and can be optimized by adjusting the compensating bias.

The invention describes a broadband matching network for coupling to an output of an amplifying device for amplifiers with a nominal operating frequency between 1 MHz and 100 MHz. The broadband matching network comprises a planar transformer with a primary winding arranged on a primary side of the broadband matching network and a secondary winding arranged on a secondary side of the broadband matching network. The primary winding is arranged to be electrically connected to the output of the amplifying device. The broadband matching network is characterized by a center frequency and a bandwidth with a frequency range of at least +/3%. A first parallel resonance frequency and a second parallel resonance frequency of the broadband matching circuit are arranged around the series resonance frequency such that a frequency dependence of a load impedance provided by the broadband matching network for the amplifying device is reduced.