A digital step attenuator (DSA) cell and related method are provided. The DSA cell includes a first branch comprising a first resistor connected, at a first side, to an input port and, at a second side, to an output port; a second resistor connected, at a first side, to the first resistor and, at a second side, to a first transistor and a third resistor connected, at a first side, to the first resistor and, at a second side, to a second transistor. Also included in the DSA cell is a second branch, in a parallel configuration with the first resistor, that includes a fourth resistor and a third transistor. Also included is a third branch, in a parallel configuration with the first resistor, that includes a fourth transistor. The first transistor, the second transistor, the third transistor, and the fourth transistor are configured to be operated independently.

A resonator device includes a substrate with a first number of fins extending over the substrate. The fins extend along the substrate in a first direction. A second number of conductive fingers are provided over the fins, which extend in a second direction perpendicular to the first direction. The first number is less than or equal to the second number. The conductive fingers are configured to receive an input signal such that the conductive fingers resonate at an output frequency. The conductive fingers define a finger pitch therebetween, and the output frequency is based on the finger pitch.

A digital step attenuator (DSA) cell and related method are provided. The DSA cell includes a first branch comprising a first resistor connected, at a first side, to an input port and, at a second side, to an output port; a second resistor connected, at a first side, to the first resistor and, at a second side, to a first transistor and a third resistor connected, at a first side, to the first resistor and, at a second side, to a second transistor. Also included in the DSA cell is a second branch, in a parallel configuration with the first resistor, that includes a fourth resistor and a third transistor. Also included is a third branch, in a parallel configuration with the first resistor, that includes a fourth transistor. The first transistor, the second transistor, the third transistor, and the fourth transistor are configured to be operated independently.

A single pole double throw (SPDT) switch with embedded attenuators includes a transmitter attenuator circuit directly connected to a common input of the SPDT switch, and a receiver attenuator circuit directly connected to the common input of the SPDT switch. Switches in the transmitter attenuator circuit and in the receiver attenuator circuit are selectively or individually set to an open state or to a closed state to directly connect the transmitter attenuator circuit or the receiver attenuator circuit to the common input. The selective setting of the states of the switches also determines a given amount of attenuation for the transmitter attenuator circuit or the receiver attenuator circuit.

A memory device includes an array of memory cells, a diode having a threshold voltage that changes with temperature, an analog-to-digital converter (ADC), and a pulse generator. The ADC includes a voltage comparator having a positive terminal coupled with the diode. The ADC further includes a first capacitor coupled between a negative terminal of the voltage comparator and ground, and a second capacitor selectively coupled between the first capacitor and a voltage reference node. The second capacitor has a smaller capacitance than that of the first capacitor. The pulse generator is coupled with the ADC and generates pulses. The pulses cause the first capacitor to connect to the second capacitor and equalize charge between the first capacitor and the second capacitor. An inverted signal of the pulses causes the second capacitor to be coupled with the voltage reference node to pre-charge the first capacitor.

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.

Digital step attenuator (DSA) and digital phase shifter (DPS) multi-stage circuit architectures that provide for high resolution. Embodiments use a dithering approach to weight bit positions to provide a much finer resolution than the lowest-valued individual stage. Bit position weights for stages are determined so as to enable selection of combinations of n bit positions that provide a desired total attenuation or phase shift range while allowing utilization of the large number of states (2.sup.n) available to produce fractional intermediate steps of attenuation or phase shift. The fractional intermediate steps have a resolution finer than the lowest-valued stage. Bit position weights may be determined using a weighting function, including weightings determined from a linear series, a geometric series, a harmonic series, or alternating variants of such series. In some embodiments, at least one bit position has a fixed value that is not determined by the bit position weighting function.

A radio frequency switch may include a common port transmitting and receiving a radio frequency signal, a first switching unit including a plurality of first switch elements connected in series and opening or closing a signal transfer path between a first port inputting and outputting the radio frequency signal and the common port, and a second switching unit having a plurality of second switch elements connected in series and opening or closing a signal transfer path between a second port inputting and outputting the radio frequency signal and the common port. The second switching unit further includes a first filter circuit unit connected to a control terminal of at least one second switch element among the plurality of second switch elements to remove at least one preset frequency band signal.

An apparatus includes a radio frequency (RF) input port, an RF output port, a variable attenuation network, a first filter network, a second filter network, and a third filter network. The variable attenuation network may be coupled between the RF input port and the RF output port. Attenuation of the variable attenuation network is controlled by a first control signal and a second control signal. The first filter network may be connected between the RF input port and the RF output port. The second filter network may be connected between the variable attenuation network and a ground potential. The third filter network may be connected between the variable attenuation network and the ground potential. The first, the second, and the third filter networks modify performance of the variable attenuation network to produce a particular tilt of a radio frequency signal passing through the apparatus between the RF input port and the RF output port. The particular tilt is selectable by adjustment of at least one of the first and the second control signals.

A method includes providing a resonant attenuation circuit comprising a first active shorting device connected to a proximal end of an inductive element and a second active shorting device connected to a distal end of the inductive element. The method also includes providing a first control signal to the first active shorting device that places the first active shorting device in a region of operation where incremental increases or decreases in voltage change a shorting impedance of the second active shorting device. A signal attenuator includes a signal propagation path and a plurality of shorting units sequentially attached to the signal propagation path and a control circuit configured to control a level of attenuation provided by each shorting unit. The control circuit and a corresponding method activates subsequent shorting units only if all previous shorting units are at least partially activated.