Dynamic bias for receiver controlled by radio link quality

An apparatus for dynamically adjusting a DC bias condition for a receiver system that is in communication with a broadcasting device via a communication link, the apparatus comprising:

• a low noise amplifier circuit that is configured to provide an output signal in response to an input signal that is received via the communication link, wherein the low noise amplifier has a power consumption that is determined by a biasing condition;
• wherein the low noise amplifier comprises a first amplifier and a second amplifier arranged in parallel, wherein a first side of a tuned circuit is coupled to a first input (INP) of the first amplifier circuit through a capacitor circuit CIP, a second side of the tuned circuit is coupled to a second input (INM) of the second amplifier circuit through a capacitor circuit CIN, wherein the first amplifier circuit is arranged to provide a first output signal (OUTP) in response to the first input signal (INP), while the second amplifier circuit is arranged to provide a second output signal (OUTM) in response to a second input signal (INM), wherein the low noise amplifier circuit further comprises resistor circuits RI1 and RI2 that are coupled in series between the INP and the INM, where a common point is biased by a DC biasing signal (VDC), wherein resistor circuits RO1 and RO2 are series coupled between the OUTP and the OUTM, where the common point is arranged to provide a sense signal (VSNS1) that is related to a DC signal level of the output of the low noise amplifiers, wherein a capacitor circuit CC is coupled between the common points to provide compensation of the first low noise amplifier and the second low noise amplifier;
• wherein the VSNS1 is coupled to a differential amplifier, wherein an output of a reference generator circuit (VBIAS_CTL) is coupled to another input of the differential amplifier circuit;
• wherein the differential amplifier is arranged to provide a control signal in response to a comparison between the VSNS2 signal and the VBIASCTL signal such that a signal VDC is adjusted to a DC bias set point for the first low noise amplifier circuit and the second low noise amplifier circuit;
• and
• a digital base-band processing means that is arranged to vary the analog reference signal via the adjustment signal based on an identified link quality for the receiver system.

An apparatus for adjusting a DC bias condition for a receiver system that is in communication with a broadcasting device via a communication link, the method comprising:

• a low noise amplifier block in the receiver system that is arranged to general an amplified signal in response to a broadcast signal received via the communication link;
• wherein the low noise amplifier block consists of a first low noise amplifier circuit and a second low noise amplifier circuit that are arranged in parallel;
• wherein a first side of a tuned circuit is coupled to a first input (INP) of the first low noise amplifier circuits through a capacitor circuit CIP, a second side of the tuned circuit is coupled to a second input (INM) of the second low noise amplifier circuit through a capacitor circuit CIN, wherein the first low noise amplifier circuit is arranged to provide a first output signal (OUTP) in response to the first input signal (INP), while the second low noise amplifier circuit is arranged to provide a second output signal (OUTM) in response to a second input signal (INM), wherein the low noise amplifier block further comprises resistor circuits RI1 and RI2 that are coupled in series between INP and INM, where a common point is biased by a DC biasing signal (VDC), wherein resistor circuits RO1 and RO2 are series coupled between OUTP and OUTM, where the common point is arranged to provide a sense signal (VSNS1) that is related to a DC signal level of the output of the low noise amplifiers, wherein a capacitor circuit CC is coupled between the common points to provide compensation of the first low noise amplifier and the second low noise amplifier;
• wherein the VSNS1 is coupled to a differential amplifier as a VSNS2 signal via a follower circuit XF1 comprising an n-type transistor biased as a follower by a current source ISN, wherein an output of a reference generator circuit (VBIAS13 CTL) is coupled to another input of the differential amplifier circuit;
• wherein the differential amplifier is arranged to provide a control signal in response to a comparison between the VSNS2 signal and the VBIASCTL signal such that a signal VDC is adjusted to a DC bias set point for the first low noise amplifier circuit and the second low noise amplifier circuit;
• a digital base-band processor means that is arranged to:
• monitor the base-band signal;
• evaluate a link quality associated with the communication link from the monitored base-band signal;
• identify an unacceptable link quality associated with the communication link;
• and
• change the DC bias condition for the low noise amplifier block when the link quality is identified as unacceptable, wherein the DC bias condition for the low noise amplifier block is adjusted by feedback from the digital base-band block such that a relatively constant gain is achieved.