Complex type sigma-delta analog to digital conversion unit and receiver
AssigneeFujitsu Limited
InventorsToshiaki Nagai, Hiroshi Yamazaki
Life of this patent
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Abstract
There is provided a complex type sigma-delta analog to digital conversion unit that includes: a first subtractor; a first filter; a first analog to digital converter; a first digital to analog converter; a first sign controller; a second subtractor; a second filter; a second analog to digital converter; a second digital to analog converter; and a second sign controller, wherein the first sign controller inverts a positive/negative sign of an output signal of the first filter in response to a control signal and outputs it to the second filter, and the second sign controller inverts a positive/negative sign of an output signal of the second filter in response to the control signal and outputs it to the first filter.
Claims18
A complex type sigma-delta analog to digital conversion unit, comprising:
- a first subtractor for carrying out subtraction by inputting a first input signal and a first feedback signal;
- a first filter for filtering an output signal of the first subtractor;
- a first analog to digital converter for converting an output signal of the first filter into a digital format from an analog format;
- a first digital to analog converter which converts an output signal of the first analog to digital converter into an analog format from a digital format and outputs the converted signal to the first subtractor as the first feedback signal;
- a second subtractor for carrying out subtraction by inputting a second input signal and a second feedback signal, the second input signal being orthogonal to the first input signal;
- a second filter for filtering an output signal of the second subtractor;
- a second analog to digital converter for converting an output signal of the second filter into a digital format from an analog format;
- a second digital to analog converter which converts an output signal of the second analog to digital converter into an analog format from a digital format and outputs the converted signal to the second subtractor as the second feedback signal;
- a first sign controller which inverts a positive/negative sign of the output signal of the first filter in response to a control signal and outputs it to the second filter;
- and
- a second sign controller which inverts a positive/negative sign of the output signal of the second filter in response to the control signal and outputs it to the first filter.
Dependencies are inferred from the claim text.