Magnetron Harmonics at Millimeter Wavelengths

Under certain operating conditions, magnetrons emit harmonics of their fundamental frequency of oscillation. With the use of the generating, filtering, and detecting equipment described here, harmonics as high as the tenth (1.25-mm wavelength) have been obtained from K-band tubes and the third (1.1 mm) from a 3.3-mm tube. The peak power at these shortest wavelengths is estimated as a few hundred microwatts, which is adequate for a variety of physical measurements. Data are given on the harmonic spectra of various tubes and tube types.