Various embodiments of the invention relate to attenuators with reduced temperature variation. By coordinating first-order resistance temperature (FORT) coefficients of resistors, embodiments of attenuator or attenuator cells are capable of achieving desired attenuation with reduced or minimized temperature variation. Such achievements in reducing temperature variation may be obtained without relying on resistors with large negative FORT coefficients. Attenuator cells may be configured as T-type attenuator cells, π-type attenuator cells, bridged-T attenuator cells, or shunt attenuators with various FORT coefficient combinations for the resistors incorporated within the attenuator cells. Furthermore, various attenuator cells may be cascaded together into a digital step attenuator with the temperature variation of those cells compensating or offsetting each other for an overall minimum temperature variation.

Various embodiments of the invention relate to attenuators with reduced temperature variation. By coordinating first-order resistance temperature (FORT) coefficients of resistors, embodiments of attenuator or attenuator cells are capable of achieving desired attenuation with reduced or minimized temperature variation. Such achievements in reducing temperature variation may be obtained without relying on resistors with large negative FORT coefficients. Attenuator cells may be configured as T-type attenuator cells, π-type attenuator cells, bridged-T attenuator cells, or shunt attenuators with various FORT coefficient combinations for the resistors incorporated within the attenuator cells. Furthermore, various attenuator cells may be cascaded together into a digital step attenuator with the temperature variation of those cells compensating or offsetting each other for an overall minimum temperature variation.

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.

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 switch assembly includes a PIN diode connected between an antenna port and a receive port, a first shunt FET device connected between the receive port and ground, a first series FET device connected between the antenna port and a transmit port, a second shunt FET device connected between the transmit port and ground, and a plurality of bias control contacts configured to receive a corresponding plurality of bias control voltages to forward bias the first shunt FET device and the first series FET device into an ON state and to reverse bias the PIN diode and the second shunt FET device into an OFF state in a transmit mode, and to reverse bias the first shunt FET device and the first series FET device into the OFF state and to forward bias the PIN diode and the second shunt FET device into the ON state in a receive mode.

A variable loss attenuator is provided. Two or more controllable stages each include a differential or single-ended π network. Each π network includes one or more series elements connected in series between the signal input and the signal output. Each series element includes a series transistor, which may potentially be provided without an inductor in parallel. Each π network includes a plurality of shunt elements each including at least one respective shunt transistor. An input stage connects to the first controllable stage and an output stage connects from the last controllable stage. Intermediate stages connect the controllable stages to one another. Each of the input stage, output stage, and intermediate stages include a right-handed transmission line component and coupled between the signal input and a first one of the controllable stages. Shunt inductors are located at inputs and outputs of each of the controllable stages.

An attenuator is configured to attenuate and phase-shift a radiofrequency signal according to a control signal, having a plurality of first attenuation cells (A.sub.1, A.sub.N1), configured to attenuate said radiofrequency signal by a predetermined value and activated according to a particular bit of the control signal, and implementing a combinatorial logic on the bits of the control signal that are used to control the first attenuation cells, and at least one second attenuation cell (B.sub.1, B.sub.M) configured to attenuate said radiofrequency signal by a predetermined value and activated according to a particular output implementing the combinatorial logic. A control node is also provided for an array antenna having such an attenuator, and an array antenna having an array of such control node and a satellite.

An attenuator is configured to attenuate and phase-shift a radiofrequency signal according to a control signal, having a plurality of first attenuation cells (A.sub.1, A.sub.N1), configured to attenuate said radiofrequency signal by a predetermined value and activated according to a particular bit of the control signal, and implementing a combinatorial logic on the bits of the control signal that are used to control the first attenuation cells, and at least one second attenuation cell (B.sub.1, B.sub.M) configured to attenuate said radiofrequency signal by a predetermined value and activated according to a particular output implementing the combinatorial logic. A control node is also provided for an array antenna having such an attenuator, and an array antenna having an array of such control node and a satellite.

A first switch is connected in parallel with a circuit element. A second switch is connected in series with a parallel circuit constituted by the circuit element and the first switch. The first switch and the second switch alternately perform on-off operation.

A first switch is connected in parallel with a circuit element. A second switch is connected in series with a parallel circuit constituted by the circuit element and the first switch. The first switch and the second switch alternately perform on-off operation.