Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modelling of Inhomogeneous Disk-Loaded Waveguides: Matrix Difference
  Equations and WKB Approximation   A new approach to the description of inhomogeneous disk-loaded waveguides
(chains of coupled resonators) is proposed. New matrix difference equations
based on the technique of coupled integral equations and the decomposition
method are obtained. Various approximate approaches have been developed,
including the WKB approximation.

19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga