An attenuation circuit with a low insertion loss is provided. The attenuation circuit includes an input to receive an input signal, an output to provide an attenuated signal, an attenuator coupled between the input and the output, the attenuator being configured to attenuate the input signal, an isolation switch constructed to isolate the attenuator from the input or the output when in a bypass mode, and a bypass switch coupled in parallel with the attenuator to couple the input to the output when in the bypass mode.

Provided herein are apparatus and methods for high linearity voltage variable attenuators (VVAs). In certain configurations, a high linearity VVA includes multiple shunt arms or circuits that operate in parallel with one another between a signal node and a first DC voltage, such as ground. Thus, the shunt arms are in shunt with respect to a signal path of the VVA. The multiple shunt arms include a first shunt arm of one or more n-type field effect transistor (NFETs) and a second shunt arm of one or more p-type field effect transistor (PFETs). The gates of the NFETs are controlled using a control voltage, and the gates of the PFETs are controlled using a complementary control voltage that changes inversely with respect to the control voltage.

An attenuation circuit comprises a signal propagation path and a plurality of shorting units (e.g., devices) sequentially attached to the signal propagation path. In some embodiments, each of one or more initial shorting units of the plurality of shorting units have a dominant intermodulation product term for a full amplitude signal that is less than that of each of one or more subsequent shorting units of the plurality of shorting units. In some embodiments, each of one or more initial shorting units are less sensitive to control voltage changes than each of one or more subsequent shorting units. In some embodiments, each of one or more initial shorting units provide higher levels of attenuation than each of one or more subsequent shorting units. A method includes providing the above attenuation circuit and controlling a level of attenuation provided by each shorting unit of the plurality of shorting units.

An electronic device includes a transceiver connected to a differential signal transmission line for transmitting a differential signal through a pair of signal lines to communicate with one or a plurality of other devices connected to the differential signal transmission line. The electronic device includes: a suppression circuit that is operated by a power source voltage to suppress waveform distortion in the differential signal transmitted through the differential signal transmission line; and a power source controller that controls supply or cutoff of the power source voltage to the suppression circuit in response to a change in a differential voltage between the pair of signal lines.

An active filter reduces Electro-Magnetic Interference (EMI) created by current flowing through a power line. The active filter connects to the power line at a single node through a connection capacitor. A sense current flows through the connection capacitor when the power line current changes. This sense current is applied to a gain control circuit having cross-coupled PNP transistors that drive currents to both terminals of a variable capacitor. The variable capacitor converts these currents to a voltage that is injected back into the power line through the connection capacitor as an injected compensation voltage that compensates for the sensed current.

An attenuator circuit is provided. The attenuator circuit includes a first input node and a second input node each configured to receive a respective one of a first input signal and a second input signal forming a differential input signal pair. Further, the attenuator circuit includes a first plurality of resistive elements coupled in series between the first input node and a first output node for outputting a first output signal. The attenuator circuit additionally includes a second plurality of resistive elements coupled in series between the second input node and a second output node for outputting a second output signal. In addition, the attenuator circuit includes a shunt path coupled to a first intermediate node and a second intermediate node. The first intermedia node is arranged between two resistive elements of the first plurality of resistive elements. The second intermedia node is arranged between two resistive elements of the second plurality of resistive elements. The shunt path comprises a switch circuit configured to selectively couple the first intermediate node and the second intermediate node based on one or more control signals.

A transmission-end impedance matching circuit operates according to a signal of an overvoltage signal source and includes a first level shifter, a voltage generating circuit, and an impedance matching circuit. The first level shifter generates a first conversion voltage according to a source signal and operates between a first high voltage and a ground voltage. The voltage generating circuit generates a second high voltage according to the first conversion voltage, the first high voltage, and a medium voltage. The impedance matching circuit includes a second level shifter, a transistor, and two resistors. The second level shifter generates a gate voltage according to the second high voltage, a low voltage, and an input signal. The transistor is turned on/off according to the gate voltage and has a withstand voltage lower than the first high voltage. Each of the two resistors is coupled between the transistor and a differential signal transmission end.

Provided is a compact digital attenuator. The compact digital attenuator includes a first attenuation cell to an nth attenuation cell, which include a plurality of attenuation cells connected to each other in parallel through a transmission line, wherein each of the plurality of attenuation cells may include a plurality of switch elements connected to each other in parallel, wherein the plurality of switch elements may be connected to the transmission line through one contact point.

An attenuator arrangement comprising at least a first attenuation path configured to couple between a signal processing chain, SPC, and a measurement apparatus; said SPC comprising a first and second SPC terminal, said SPC configured to apply one or both of a gain and phase change on a signal passed between the SPC terminals; said measurement apparatus configured to measure one or both of the gain and the phase change applied by SPC by coupling to and receiving signals from said SPC terminals; wherein one of said first SPC terminal and said second SPC terminal is coupled to the measurement apparatus through said first attenuation path; and wherein the at least first attenuation path of the attenuator arrangement is configured to provide, selectively, for attenuation of the signal to the measurement apparatus to make the signal power of the signals from said SPC terminals more equal.

An apparatus including an electronic circuit. The apparatus includes a path unit configured to form a first impedance for controlling a gain of an input signal. The apparatus also includes a shunt unit configured to form a second impedance for performing attenuation between the path unit and a ground, wherein the path unit forms the first impedance using an on-resistance of at least one transistor.