Comparison of AM Noise in Commercial Amplifiers and Oscillators at X-Band

In this paper the authors discuss the importance of amplitude-modulated (AM) noise. AM noise is often neglected and considered as a minor problem. However, AM noise can become very important in high performance systems that require ultra-low phase-modulated (PM) noise and where the designer is struggling with AM-PM conversion. Few discussions are available on the AM noise of different microwave components. In this paper we report the AM noise of different commercial amplifiers and oscillators at 10 GHz. To adequately characterize the AM noise of high performance amplifiers, we design and investigate an air-dielectric cavity resonator oscillator with outstanding AM noise performance. We also present the AM noise of different AM detectors at 10 GHz