Noise figure (NF) represents a fundamental characteristic parameter of radio frequency (RF)/microwave devices, serving as a critical metric for evaluating the performance of amplifiers, receivers, and even entire systems. As a traditional RF/microwave test item, NF quantifies the internal noise generated by the device under test (DUT) and reflects the degradation of the signal-to-noise ratio (SNR), which is represented by the ratio between input and output SNRs.
