A Step-by-Step Noise Figure Debug Methodology

The sensitivity of a radio receiver is a key operational parameter for any radio communications system. Noise Figure (NF), which defines the noise performance of a receiver, directly dictates the minimum sensitivity achievable. Meeting the target NF is a multifold task which involves careful design of circuit and board along with the right test methodology. Since no RF test ports are available from the device, it is a tedious process to root-cause the issue of high NF. In this paper, extensive test methodology is discussed which helped us validate various silicon parameters to pin point the issue. Novel techniques are proposed to measure parameters with limited visibility in silicon. Important design learnings were established as a result of this validation. These were used in the current generation device to meet the stringent performance requirements in both simulation and silicon.