Lower bound on the eigenvalues of the characteristic equation for an arbitrary multilayered gyromagnetic structure with perpendicular magnetization (original) (raw)

We have measured the phase noise of an 8.5 GHz GaAs MESFET amplifier at temperatures from 1.7 K to 300 K for input powers from-30 dBm to well past the 1 dB gain compression point and for sideband frequencies from 0.1 Hz to 25 kHz. The observed flicker phase noise was independent of input power, even at levels producing 4 dB of gain compression, and also changed very little with bias conditions. The intrinsic phase noise at low temperatures (observed below 2.17 K, where an extrinsic effect due to the bubbling of the liquid helium coolant disappears) was slightly higher than that observed at room temperature, However, we saw no sign of the dramatic increase in flicker phase noise at low Manuscript