Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Proposte di Antenne generatrici di Fasci Non-diffrattivi per micro-onde
  (Proposal of apertures generating Nondiffracting Beams of microwaves)   We propose in detail Antennas for generating Nondiffracting Beams of
Microwaves, for instance with frequencies of the order of few GHz, obtaining
fair results even when having recourse to realistic apertures, with a quite
reasonable diameter. The present proposal refers to sets of suitable annular
slits. The possible applications are various, including remote sensing. The
paper is in Italian. [Si propongono in dettaglio Antenne per la generazione di
fasci non-diffrattivi di microonde, per frequenze ad esempio dell'ordine della
decina di GHz, ottenendo discreti risultati pur ricorrendo ad antenne
realistiche di diametro ridotto. La proposta e' quella di usare un set di
opportuni Annular Slits. Le applicazioni possibili sono varie, includendo il
remore sensing.]

36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
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The categories of this paper are: eess
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
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The categories of this paper are: q-fin