GB649151A - Wave guide system - Google Patents

Abstract

649,151. Wave-guides. RADIO CORPORATION OF AMERICA.. April 12, 1948, No. 10123. Convention date, May 14, 1947. [Class 40 (viii)] [Also in Group XL (c)] A wave-guide system comprises a main guide connecting a source to a load and having increasing transverse dimensions from source to load and branch guides each connecting a source of lower frequency to the main guide at points at which its dimensions become large enough to transmit the lower frequencies. Energy of wavelength #A is fed to a tapered wave-guide 5 from a source A at the smaller end of width a. Energy of wavelengths #B, #C is fed to the guide 5 by branch guides 3, 4 of width b, c respectively. The branch guides are so positioned that energy from each source is only propagated along the main guide away from source A. The branch guide 3 is provided with a filter stub 26 comprising a section of width a and length adjusted to prevent energy of wavelength #A entering the guide 3, and a section of width b and length adjusted to reduce the effect of the discontinuities in the branch guide. The branch guide 4 is provided a filter and matching stub 15 similar to stub 26 but adjusted to prevent energy of wavelength #B entering the branch, and a second filter stub 16 comprising three sections of width a to prevent energy of wavelength #A entering the guide. The three sections may be so adjusted that side bands are also excluded. Branch guide 4 may also have a third stub similar to stub 16. The main guide may comprise rectangular sections of uniform dimensions connected by pyramidal sections, and the branch guides may be bent through 90 degrees at their junctions with the main guide.