Methods and devices used in mobile receiver front end to support multiple paths and multiple frequency bands are described. The presented devices and methods provide benefits of scalability, frequency band agility, as well as size reduction by using one low noise amplifier per simultaneous outputs. Based on the disclosed teachings, variable gain amplification of multiband signals is also presented.

For example, it becomes possible to suppress an increase in hardware scale and costs and to perform signal processing according to an input signal. Provided is an information processing apparatus including a filter processing unit that performs filtering on an input signal, and a filter setting unit that makes a setting of the filtering such that a sound of a target audio source type in the input signal is controlled and the setting is determined using an estimation result obtained from the input signal by an estimation algorithm.

For example, it becomes possible to suppress an increase in hardware scale and costs and to perform signal processing according to an input signal. Provided is an information processing apparatus including a filter processing unit that performs filtering on an input signal, and a filter setting unit that makes a setting of the filtering such that a sound of a target audio source type in the input signal is controlled and the setting is determined using an estimation result obtained from the input signal by an estimation algorithm.

A variable-gain amplifier and a phased array system are provided. A variable-gain amplifier includes a cascode circuit comprising a first amplification transistor and a second amplification transistor array that are cascaded, the second amplification transistor array comprising a plurality of second amplification transistors connected in parallel and configured to output an adjustable current to an output matching network, the first amplification transistor is a common-source transistor, the plurality of second amplification transistors are common-gate transistors, or the cascode circuit is a common-emitter common-base circuit, the first amplification transistor is a common-emitter amplification circuit, and the second amplification transistor array is a common-base amplification circuit. The variable-gain amplifier further including a variable capacitor circuit coupled to the second amplification transistor array and coupled to the output matching network at first nodes.

High-data rate channel interface modules and equalization methods employing a finite impulse response (FIR) analog receive filter. Embodiments include an illustrative channel interface module having multiple amplifier-based delay units arranged in a sequential chain to convert an analog input signal into a set of increasingly-delayed analog signals that are weighted and combined together with the analog input signal to form an equalized signal; and a symbol decision element operating on the equalized signal to obtain a sequence of symbol decisions. An interface that extracts received data from the sequence of symbol decisions. The delay units may employ one or more delay cells each having a common-source amplifier stage followed by a source follower output stage, the two stages providing approximately equal portions of the propagation delay. An enhanced gate-to-drain capacitance in the common-source amplifier may increase propagation delay while reducing bandwidth limitations.

The present invention is directed to electrical circuits. More specifically, embodiments of the presentation provide a CTLE module that includes a two compensation sections. A high-frequency zero RC section is in the source of the differential pair and close to the bias current source. A low-frequency zero section is coupled to an output terminal and configured outside the input signal path. A DC gain tuning section is coupled to the low-frequency zero section. There are other embodiments as well.

The disclosed technology is related to a radio-frequency (RF) amplifier having a bypass circuit and a resonant structure to improve performance in a bypass mode (e.g., a low gain mode). The disclosed amplifiers have a resonant structure that effectively isolates an amplifier core from a bypass circuit. For example, in a bypass mode, the resonant structure is configured to create an open impedance looking into the amplifier core input. This effectively removes any loading from the amplifier core to the bypass circuit. The disclosed amplifiers with resonant structures improve linearity performance in bypass modes due at least in part to the open impedance to the amplifier core provided by the resonant structure.

A communication system includes a demodulator configured to demodulate a modulated signal responsive to a first carrier signal. The demodulator includes a filter and a gain adjusting circuit. The filter is configured to generate a filtered first signal based on a first signal. The first signal is a product of the first carrier signal and the modulated signal. The filter has a gain adjusted based on a set of control signals. The gain adjusting circuit is coupled to the filter, and is configured to generate the set of control signals based on at least a voltage of the filtered first signal. The gain adjusting circuit includes a first peak detector coupled to the filter. The first peak detector is configured to output a peak value of the voltage of the filtered first signal.

A PA module includes a previous stage amplification element to amplify a high-frequency signal, a posterior stage amplification element to amplify the high-frequency signal amplified by the previous stage amplification element, and a variable filter circuit arranged between the previous stage amplification element and the posterior stage amplification element and to vary a pass band and an attenuation band in accordance with a frequency band of the high-frequency signal, in which the variable filter circuit includes a filter portion and switches, the previous stage amplification element, the switches, and the posterior stage amplification element are arranged on a mounting surface of a substrate, the filter portion is stacked and arranged so as to overlap with at least one of the previous stage amplification element, the switches, and the posterior stage amplification element when the substrate is viewed in a plan view.

One aspect of the present disclosure relates to a method for operating an amplifier, the amplifier including a variable resistor coupled between a source of a first input transistor and a source of a second input transistors, and a variable capacitor coupled between the source of the first input transistor and the source of the second input transistor. The method includes adjusting a resistance of the variable resistor to adjust a low-frequency gain of the amplifier, and adjusting a capacitance of the variable capacitor in an opposite direction as the adjustment to the resistance of the variable resistor.