Two- and three-loop superdirective receiving antennas

Abstract

The characteristics of twoand three-loop superdirect ive a nte nn a arrays arc presen led . At VLF, t his type of array appears to h ave m any d esirab le qua li t ies, an d the usua l dctr'i me ntal ch a racteristics associated wi th superdirectivity are less in evid e nce. It is shown that the beamwid th is n arrowest, the front-to-back voltage and power ratios m'e g reat est, a nd the posit ion of t he back lobes and nulls are most invari a nt whf'n closel.v spaeed loops are used . Inequaliti es in s ignals from the individua l loops tend to obscure t he front a nd back lobe' and limit t he proxim ity of th e loops.