Digital switched attenuator
AssigneeSkyworks Solutions, Inc.
InventorAdrian John Bergsma
Life of this patent
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Abstract
An attenuation cell is provided for use in a switched attenuator. The attenuation cell includes an attenuation path that has an input, a first switch, a resistive network, a second switch, and an output. The resistive network provides a desired attenuation from the input to the output. The attenuation cell also includes a bypass path in parallel with the attenuation path with a bypass switch between the input and the output. The attenuation cell also has a shunt switch coupled between the resistive network and a reference node to selectively connect the resistive network to the reference node.
Claims23
A switched attenuator comprising:
- an input;
- an output;
- a plurality of attenuation cells directly coupled in series between the input and the output, each respective attenuation cell of the plurality of attenuation cells having an attenuation state, a bypass state, and an isolated state;
- and
- a controller configured to operate the switched attenuator in one of an attenuation mode of operation, a bypass mode of operation, and an isolation mode of operation by controlling each respective attenuation cell of the plurality of attenuation cells to operate in one of the attenuation state, the bypass state, and the isolated state.
A switched attenuator comprising:
- a signal input;
- a signal output;
- a plurality of attenuation cells directly coupled in series between the signal input and the signal output, each respective attenuation cell of the plurality of attenuation cells including an attenuation path having a first switch, a resistive network, and a second switch connected in series, a bypass path in parallel with the attenuation path and having a bypass switch, and a shunt switch coupled between the resistive network and a reference node;
- and
- a controller configured to operate the switched attenuator in one of an attenuation mode of operation, a bypass mode of operation, and an isolation mode of operation by controlling the first switch, the second switch, the bypass switch, and the shunt switch of each respective attenuation cell of the plurality of attenuation cells.
A method of controlling an adjustable attenuator, the adjustable attenuator having a signal input and a signal output and including a plurality of attenuation cells directly coupled between the signal input and the signal output, each respective attenuation cell of the plurality of attenuation cells including a resistive network selectively coupled between an input and an output, the method comprising:
- receiving an input signal from the signal input;
- operating the adjustable attenuator in an attenuation mode of operation to attenuate the input signal and provide an attenuated output signal to the signal output by attenuating the input signal with the resistive networks of a first portion of attenuation cells of the plurality of attenuation cells and selectively bypassing the resistive networks of the remaining portion of the plurality of attenuation cells;
- operating the adjustable attenuator in a bypass mode of operation to provide an output signal to the signal output that is substantially the same as the input signal received at the signal input by selectively bypassing the resistive network of each respective attenuation cell of the plurality of attenuation cells;
- and
- operating the adjustable attenuator in an isolation mode of operation to attenuate and reflect the input signal to the signal input by attenuating the input signal with the resistive network of at least one first attenuation cell of the plurality of attenuation cells and reflecting the input signal by selectively decoupling the resistive network of at least one second attenuation cell from at least the input of the at least one second attenuation cell, the at least one second attenuation cell being disposed less proximate the signal input than the at least one first attenuation cell.
Dependencies are inferred from the claim text.