The present invention is directed to electrical circuits. In a specific embodiment, the present invention provides variable gain amplifier that includes an impedance ladder and a control circuit. The impedance ladder includes n switches configured in parallel. The control circuit includes a digital-to-analog converter and an amplifier. The control circuit generates n control signals for the n switches. There are other embodiments as well.

A TX-TX pre-compensation system that estimates unwanted coupling in a victim transmit chain caused by an aggressor transmit chain and injects a pre-compensation signal to cancel out the estimated coupling. In some embodiments, a signal measurement module estimates the amplitude, phase, and envelope delay of the coupling and an isolation pre-compensation module generates the pre-compensation signal based on the estimated amplitude, the estimated phase, the estimated envelope delay, and the difference between the carrier frequencies of the transmit chains. Since the phase of the coupling may be affected by the carrier frequency of the transmit chains, in some embodiments the phase of the pre-compensation signal is adjusted in response to a change in carrier frequency. Since the amplitude of the coupling may be affected by attenuator gain settings, in some embodiments the amplitude of the pre-compensation signal may be adjusted in response to a change in attenuator gain setting.

A method for receiving data includes receiving a transmission signal through a channel, adjusting the intensity of the transmission signal to generate an adjusted transmission signal according to an analog gain level, converting the adjusted transmission signal into a digital signal, filtering the digital signal to generate a filtered signal according to a set of filter coefficients, and adjusting intensity of the filtered signal according to a digital gain level. The method further includes, in a training mode, estimating a transmission condition of the channel and adjusting the analog gain level and the digital gain level according to the transmission condition for obtaining convergent values for the set of filter coefficients before the training mode ends, and in a data mode, performing a gain adjustment operation to adjust the analog gain level and to adjust the digital gain level according to the adjustment made to the analog gain level.

Disclosed herein are signal amplifiers that include a plurality of switchable amplifier architectures so that particular gain modes can use dedicated amplifier architectures to provide desired characteristics for those gain modes, such as low noise figure or high linearity. The disclosed signal amplifier architectures provide tailored impedances using a degeneration block or matrix without using switches in the degeneration switching block. The disclosed signal amplifier architectures provide a plurality of gain modes where different gain modes use different paths through the amplifier architecture. Switches that are used to select the path through the amplifier architecture also provide targeted impedances in a degeneration block or matrix. The switches that select the gain path are provided in the amplifier architecture and are thus not needed or used in the degeneration block, thereby reducing the size of the package for the amplifier architecture.

Techniques maintaining receiver reliability, including determining a present attenuation level for an attenuator, wherein the attenuation level is set by a gain controller, determining a relative reliability threshold based on the present attenuation level, receiving a radio frequency (RF) signal, determining a voltage level of the received RF signal, comparing the voltage level of the received RF signal to the relative reliability threshold to determine that a reliability condition exists, and overriding, in response to the determination that the reliability condition exists, the present attenuation level set by the gain controller with an override attenuation level based on the present attenuation level.

A receiver (100) with an antenna array (150) provides interference reduction for blocking signals received by the receiver (100) by controlling different receiver blocks (110) associated with different antenna elements (112) of the array (150) differently, particularly for those antenna elements (112) in the corner or proximate a corner or edge of the array (150), responsive to a power level of a combined signal resulting from all antenna elements (112). As a result, the solution presented herein enables a receiver (100) to more accurately target the gain control such that the antenna elements (112) and associated receiver circuitry (110) most likely to be impacted by unwanted signals have a reduced gain, while the antenna elements (112) and associated receiver circuitry (110) less likely to be impacted by unwanted signals can operate with a higher gain.

A technology is described for adjusting repeater gain based on user equipment need. A repeater can be configured to receive a downlink signal strength indicator value of a user equipment (UE) via a wireless connection of the UE with the repeater. The repeater can be further configured to select a threshold value for the downlink signal strength indicator value. The repeater can be further configured to reduce or bypass a downlink repeater gain level when the downlink signal strength indicator value is greater than the threshold value.

Various technologies described herein pertain to variable gain amplification for a sensor application. A multistage variable gain amplifier system provides variable gain amplification of an input signal. The multistage variable gain amplifier system includes a plurality of amplification stages. The multistage variable gain amplifier system further includes a power detector configured to detect a power level of an input signal received by the multistage variable gain amplifier system. The multistage variable gain amplifier system also includes a controller configured to control the amplification stages based on the power level of the input signal. The multistage variable gain amplifier system can output an output signal such that the amplification stages are controlled to adjust a gain applied to the input signal by the multistage variable gain amplifier system to output the output signal.

An electronic device may include wireless circuitry with a baseband processor, a transceiver circuit, a front-end module, and an antenna. The front-end module may include amplifier circuitry such as a low noise amplifier for amplifying received radio-frequency signals. The low noise amplifier is operable in a non-carrier-aggregation (NCA) mode and a carrier aggregation (CA) mode. The low noise amplifier may include a first input stage, a second input stage, a complementary degeneration transformer, and an input impedance compensation circuit. During the NCA mode, the first input stage is turned on while the second input stage is turned off, the degeneration transformer is controlled to provide maximum inductance, and the compensation circuit is turned on to provide input matching. During the CA mode, the first and second input stages are turned on, the degeneration transformer is adjusted to provide less inductance, and the compensation circuit is turned off.

Methods and devices to improve the insertion loss at the LNA input of RF receivers are disclosed. The described methods and devices make use of the band switches in OFF state to improve the layout design, insertion loss and NF. Exemplary embodiments incorporating the disclosed concept are also presented.