Automatic gain control circuit with background calibration
AssigneeRafael Microelectronics, Inc.
InventorsMeng-Ping Kan, Kuan-Ming Chen, Benjamin Chiang, Tzy-Yun Wang
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Abstract
An automatic gain control circuit for controlling an LNA for inputting signals carrying packets, the automatic gain control circuit can perform a background calibration in the non-preamble time region of a first packet for pre-determining a gain adjustment to the LNA before the next preamble of a second packet arrives, so that the gain of the LNA can be adjusted immediately according to the pre-determined gain adjustment when the next preamble of the second packet arrives.
Claims16
An automatic gain control circuit, for controlling a first amplifier for inputting signals carrying packets, each packet comprising a preamble field within a preamble time region and a non-preamble field within a non-preamble time region, wherein a mixer is coupled to the first amplifier to receive outputted signals of the first amplifier, wherein said automatic gain control circuit comprises:
- a power detector for receiving a first signal outputted from the first amplifier and to output a voltage level representing a power level of the first signal, wherein the power detector is coupled to the first amplifier to receive the first signal via a conductive path that does not include said mixer;
- and a second amplifier coupled to the power detector to adjust said voltage level outputted from the power detector, wherein the second amplifier is coupled to the power detector to receive said voltage level via a conductive path that does not include said mixer and a gain of the second amplifier is adjusted while in the current non-preamble time region such that the adjusted voltage level falls in a pre-determined range, so that a gain of the first amplifier is capable of being adjusted while in the next preamble time region immediately following the current non-preamble time region, according to the adjusted gain of the second amplifier.
A receiver with an automatic gain control, said receiver comprising:
- a first amplifier, for inputting signals carrying packets, each packet comprising a preamble field within a preamble time region and a non-preamble field within a non-preamble time region, wherein a mixer is coupled to the first amplifier to receive outputted signals of the first amplifier;
- a power detector, for receiving a first signal outputted from the first amplifier and to output a voltage level representing a power level of the first signal, wherein the power detector is coupled to the first amplifier to receive the first signal via a conductive path that does not include said mixer;
- and
- a second amplifier, coupled to the power detector to adjust said voltage level outputted from the power detector, wherein the second amplifier is coupled to the power detector to receive said voltage level via a conductive path that does not include said mixer and a gain of the second amplifier is adjusted while in the current non-preamble time region such that the adjusted voltage level falls in a pre-determined range, so that a gain of the first amplifier is capable of being adjusted while in the next preamble time region immediately following the current non-preamble time region, according to the adjusted gain of the second amplifier.
Dependencies are inferred from the claim text.