Provided is a low-noise amplifier that can effectively suppress noise included in an input signal. A low-noise amplifier according to an embodiment of the present invention amplifies a reception signal in a predetermined frequency band from an antenna. The low-noise amplifier includes an input terminal, an output terminal, a field effect transistor, and a branch circuit. The branch circuit is branched from a circuit connecting the input terminal or the output terminal to the field effect transistor. The branch circuit is connected to the elastic wave resonator.

An active device and circuits utilized therewith are disclosed. In an aspect, the active device comprises an n-type transistor having a drain, gate and bulk and a p-type transistor having a drain, gate and bulk. The n-type transistor and the p-type transistor include a common source. The device includes a first capacitor coupled between the gate of the n-type transistor and the gale of the p-type transistor, a second capacitor coupled between the drain of the n-type transistor and the drain of p-type transistor and a third capacitor coupled between the bulk of the n-type transistor and the bulk of p-type transistor. The active device has a high breakdown voltage, is memory less and traps even harmonic signals.

A receiver front end capable of receiving and processing intraband non-contiguous carrier aggregate (CA) signals using multiple low noise amplifiers (LNAs) is disclosed herein. A cascode having a common source input stage and a common gate output stage can be turned on or off using the gate of the output stage. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input stage of each cascode. Further switches used for switching degeneration inductors, gate/sources caps and gate to ground caps for each legs can be used to further improve the matching performance of the invention.

A circuit for implementing a multifunction output generator is described. The circuit comprises an amplifier circuit having a first input and a second input; a voltage generator coupled at a first node to a first input of the amplifier circuit; a controllable current source configured to provide a variable current to the first node; and a switching circuit enabling the operation of the amplifier circuit in a first mode for sensing a temperature and a second mode for providing a reference voltage. A method of implementing a multifunction output generator is described.

According to an embodiment, a method includes amplifying a signal provided by a capacitive signal source to form an amplified signal, detecting a peak voltage of the amplified signal, and adjusting a controllable impedance coupled to an output of the capacitive signal source in response to detecting the peak voltage. The controllable impedance is adjusted to a value inversely proportional to the detected peak voltage.

A sensor amplifier arrangement includes an amplifier having a signal input to receive a sensor signal and a signal output, and a feedback path that couples the signal output to the signal input, wherein the feedback path includes an anti-parallel circuit of diodes, and a voltage divider including a first and a second divider resistor and a voltage divider tap between the first and the second divider resistor, wherein the voltage divider couples the signal output to a reference potential terminal, and the voltage divider tap is coupled to the anti-parallel circuit of diodes and the anti-parallel circuit of diodes is coupled to the signal input.

A circuit module includes a power amplifier, a switch, and a bypass capacitor. The power amplifier has a signal input node coupled to an input signal, a signal output node to generate an output signal, and a power input node coupled to a supply output signal of a supply modulator. The switch is coupled between the power input node of the power amplifier and the bypass capacitor. The bypass capacitor is an equivalently removable bypass capacitor coupled between the switch and a ground level.

A power supply to power amplifier (PA) distribution network may include a first power supply. The PA distribution network may further include at least one power amplifier. The power amplifier may be coupled to the first power supply. The power amplifier may include a driver stage and a power stage. The power amplifier may be coupled to the first power supply via a first switch.

A tunable filter is described where the frequency response as well as bandwidth and transmission loss characteristics can be dynamically altered, providing improved performance for transceiver front-end tuning applications. The rate of roll-off of the frequency response can be adjusted to improve performance when used in duplexer applications. The tunable filter topology is applicable for both transmit and receive circuits. A method is described where the filter characteristics are adjusted to account for and compensate for the frequency response of the antenna used in a communication system.

According to an embodiment, a method includes amplifying a signal provided by a capacitive signal source to form an amplified signal, detecting a peak voltage of the amplified signal, and adjusting a controllable impedance coupled to an output of the capacitive signal source in response to detecting the peak voltage. The controllable impedance is adjusted to a value inversely proportional to the detected peak voltage.