Effects and measurement of harmonics in high power waveguide systems

A measuring technique is described that can be used to determine qualitatively and quantitatively all higher order modes propagating in a straight, lossless, rectangular waveguide. Calibrated electric probes are used to sample the electric field strengths at various locations on the waveguide walls. These locations are confined to specified transverse cross-sections. Results of measurements of second and third harmonic power generated by a high power, S-band radar transmitter are friefly discussed.