Analysis and design of terahertz waveguide filter

Tolerance analysis of a filter with different cavity widths is presented, showing that different widths should be used for filters in different frequency bands in order to degrade manufacturing tolerance. Moreover, the effect of various resonant modes is also analyzed. It is found that in terahertz, the cavity length of TE101 mode is smaller than the width of the cavity, and in this case higher resonant modes should be used to increase the Q factor and degrade the tolerance of manufacturing. A 4th order 0.34 THz band pass filter is illustrated. Its measurement shows that the minimum loss is -0.73 dB and all loss is within -2 dB in the frequency range of 0.335 THz to 0.349 THz.