Electron Beam Test System for GHz-Waveform Measurements on Transmission Lines within MMIC

A system for measurements of waveforms on transmission lines within microwave integrated circuits based on a scanning electron microscope has been developed. For the first time it offers simultaneously a spatial resolution of less than 1Ovm, a temporal resolution better than 10ps, and in principle a frequency range up to 40GHz. Additionally, due to the use of a special phase-shift technique, the repetition rate of the electron beam pulses and the operating frequency of the MMIC can be chosen arbitrary. The performance of this test system is demonstrated by quantitative waveform measurements up to 24GHz. On coplanar transmission lines built on semiinsulating GaAs with center conductor widths of 40¿m and 20¿m, relative power levels could be estimated.