Standard mismatch - the production of controlled small reflections in waveguides
Journal of Research of the National Bureau of Standards Section C Engineering and Instrumentation
Th e refl ection prope rti es of poss ible suitabl e stru ct ures, for produ cing small acc urately contro ll ed re fl ec tion s in rectangular waveguid e, a re examin ed and a c hoi ce made of cylindri cal posts for a more detai led stud y. A numbe r of so urces of e rror du e to ohmi c loss, positioning and s ha pe are inv es tigated, and it is sho wn th at both th e indu ctive a nd capac itive post ca n mee t reaso nabl e s pecifi ca tion s but that the latte r is th e more suitab le on alm
... e suitab le on alm os t a ll co unt s. Atte nti on to pos t s ize a nd tilt is n ece~sary, but th e acc ura cies needed li e well within th e ran ge ac hi eva ble by good e ngin ee rin g practice. Key Words: Co ntroll ed small reflections; mi sma tc h ; refl ec tor posts ; waveguid e . List of Principal Symbols a rectan gular waveguide broad dim e nsio n, unit vectors, rectan gular waveguide narrow dim e ns ion , post di splacement fro m guid e wa ll , (-1)t/2, wave numbe r in free s pace, 21T/"A., wave numbe r in waveguid e, 21T/"A.!I' post radiu s, re Rec tion coe ffi cie nt , tran s mi ss ion coe ffi cie nt , se ri es reac tan ce (normali zed), parallel reac tan ce (normalized), pos t impedan ce (normalized) , co rrection factors du e to pos t co ndu ctan ce (see eqs (4) and (12) ) , free space wavele ngth , guid e wav e le ngth , post tilt a ngle, and post co ndu c tivit y.