Programmable baseband filter for selectively coupling with at least a portion of another filter

An apparatus, comprising:

• a first filter comprising a first amplifier;
• a second filter comprising a second amplifier;
• and
• a first set of one or more switching devices configured to selectively couple the first filter to the second filter, wherein the first set of one or more switching devices is configured to selectively couple inputs and outputs of the first and second amplifiers together, wherein:
• the first filter further comprises a first resistor coupled between a first input of the first filter and an input of the first amplifier;
• the second filter further comprises a second resistor coupled between a second input of the second filter and an input of the second amplifier;
• and
• the apparatus further comprises a second set of one or more switching devices configured to selectively couple the first and second inputs together.

An apparatus, comprising:

• a first filter comprising a first amplifier;
• a second filter comprising a second amplifier;
• and
• a first set of one or more switching devices configured to selectively couple the first filter to the second filter, wherein the first set of one or more switching devices is configured to selectively couple inputs and outputs of the first and second amplifiers together, wherein:
• the first and second amplifiers are configured as a first type of amplifier;
• the apparatus further comprises a third amplifier coupled between the first amplifier and an output of the first filter, and a fourth amplifier coupled between the second amplifier and an output of the second filter, the third and fourth amplifiers configured as a second type of amplifier;
• and
• the apparatus further comprises a second set of one or more switching devices configured to selectively couple inputs and outputs of the third and fourth stage amplifiers together.

A method, comprising:

• operating a first filter to filter a first input signal to generate a first output signal;
• operating a second filter to filter a second input signal to generate a second output signal;
• and
• selectively coupling at least a portion of the second filter with the first filter to filter a third input signal to generate a third output signal,
• wherein the at least a portion includes passive components but not active components or wherein the at least a portion includes active components but not passive components.