modes designation for cavity resonators

i was reading modes of cavity resonators and come across TE10δ mode

can anyone explain what does δ means in this mode designation.


any comments would be welcome

regards

TE10δ is a mode for cylinder cavity and δ is refered to phi dimenstion in the cylinderical coordinate system, i guess

Are you serious?! Cylinder cavity doesn't support TE10 at all, most of the case TE11 mode is the fundamental mode and then TM01, TE21......

TE10δ is typical mode for rectangular cavity. δ here means δth harmonic mode, also means in Z direnction (wave transmitting direction) has δ *half-wavelength. e.g. TE101 has 1 half-wavelength in Z and TE102 has 2 half-wavelength in Z. TE10δ has a 180 phase degrees difference from TE10(δ-1) mode.

Hope it helps.