NORMAL AND ANOMALOUS DOPPLER EFFECTS IN A DIELECTRIC-LOADED STRIPLINECYCLOTRON-RESONANCE MASER OSCILLATOR

The slow-wave cyclotron-resonance master (CRM) oscillator experiment p resented in this paper produces output signals that correspond to norm al and anomalous Doppler shifts. The table-top low-voltage (<10 kV) CR M device consists of a double stripline waveguide. The metal strips ar e loaded by dielectric slabs; thus the waveguide supports slow waves w ith different phase velocities in odd and even quasi-TEM modes. The su ppression of axial electric-field components in this waveguide elimina tes the Cherenkov interaction as a parasitic effect to the slow-wave C RM. Oscillations are observed in the frequency range 3-15 GHz. Doppler shifts of 30% down and 150% up are measured with respect to the elect ron cyclotron frequency. These agree with the normal and anomalous tun ing conditions, respectively. The dielectric-loaded stripline scheme i s discussed for practical slow-wave CRM devices.