Insulated loop antenna immersed in a conducting medium

Abstract

A so lu t io n is given for t he fi elds of a circul a r loop in a co ndu ctin g m edium . Th e loop is ass umed to ha \'e a uniform current, a nd it is enclosed by a spherical insul ati ng cavity. The imped a nce of t h e loop is a lso co nsidered . It is shown t hat t he p ower radi ated fr o m t he loop va ri es approxim ately as the r eciprocal of t he radius of t he cavity for it sp ecifi ed loop curren t. Furthermore, if t h e cav ity is electri call y sm all , r elative to t h e ex terna l m edium, t he radiation fi eld is not sign ifi cantly a ffected by t he presen ce of the cay ity.