Waveguide arrangement for low-attenuation transmission of microwaves of the dominant mode

摘要

It is intended to specify a waveguide arrangement which transmits microwaves of the dominant mode with as little attenuation as possible, using means of little complexity. A transition waveguide (HL2), which consists of a plurality of sections (A1...A7) of graduated cross-section, is connected to at least one end of a multi-mode transmission waveguide (HL1). Arranged at the side of the transition waveguide (HL2) is at least one chamber (K11, K12, K21, K22) which is at least partially filled with an absorbent material (A3) and is coupled to the transition waveguide (HL2) at a point where it is possible to output only at least one higher mode and not the dominant mode. Those sections (A1) of the transition waveguide in which other higher modes are capable of existence, for which no output is provided, and those sections (A2) which are adjacent to these sections and cause periodic attenuation of the said modes are dimensioned in terms of their length such that forward-running and backward-running wave elements which occur in these sections (A1, A2) of each mode are superimposed in antiphase. This waveguide arrangement is particularly suitable for the transmission of the dominant mode at frequencies which are greater than twice its cut-off frequency. <IMAGE>