▁of ▁these ▁anten nas ▁and ▁was ▁used ▁as ▁the ▁text book . ▁He ▁created ▁a ▁general ▁theory ▁of ▁frequency ▁stabil ization , ▁developed ▁a ▁theory ▁of ▁calculation ▁of ▁pass ive ▁v ib rat ors . ▁He ▁conducted ▁the ▁study ▁of ▁the ▁phenomen on ▁of ▁f lare ▁exp iration ▁of ▁the ▁anten na ▁wire , ▁the ▁results ▁of ▁it ▁were ▁used ▁in ▁the ▁design ▁of ▁anten nas ▁and ▁super - power ful ▁Soviet ▁short wave ▁rad ios . ▁He ▁created ▁the ▁general ▁theory ▁of ▁receive ▁anten nas ▁based ▁on ▁an ▁elect rod ynamic ▁principle ▁of ▁reci pro city , ▁and ▁it ▁became ▁conventional ▁in ▁radio ▁engineering . ▁He ▁carried ▁out ▁a ▁number ▁of ▁theoretical ▁and ▁experimental ▁studies ▁of ▁band ▁anten na e ▁( in - phase ▁and ▁rh omb ic ), ▁developed ▁the ▁theory ▁of ▁rh omb ic ▁anten nas , ▁invent ed ▁two ▁advanced ▁systems ▁of ▁rh omb ic ▁anten nas . ▁Also ▁developed ▁the ▁theory ▁of ▁in hom ogeneous ▁lines ▁with ▁imped ance ▁that ▁var ies ▁expon entially . ▁Pro posed ▁and ▁developed ▁a ▁general ▁theory ▁and ▁methods ▁of ▁calculation ▁of ▁closed ▁oscill ating ▁elect romagnet ic ▁devices , ▁later ▁known ▁as ▁the ▁" volume ▁reson ators ", ▁which ▁are ▁the ▁basis ▁of ▁many ▁systems ▁of ▁U H F ▁and ▁mic row ave ▁bands . ▁He ▁developed ▁a ▁new ▁type ▁of ▁anten na ▁- ▁diff raction ▁anten na ▁( one ▁of ▁its ▁species ▁is ▁slot ▁anten na ). ▁Also ▁proposed ▁the ▁theory ▁and ▁method ▁of ▁prepar ation ▁of ▁the ▁travel ing ▁wave