Self and mutual admittances of waveguides radiating into plasma layers

Th e self a nd mu t ual a dm ittance of waveg uide backed slots r ad iatin g in to a plas ma (o r di electri c) laye r has been formu lated in a late ra lly unbounded geo metry. Th e admi ttance ex pression in vol ves integ rals t hat may be a pproximated by s umrnations for numeri cal calculation s. For a constant mesh size a pproximation to t he in teg rals t he s umm ations a re t he sa me as obtain ed in earli er wor k, where thc plas ma layc rs arc co nsidered to be within a wide waveg uid e. Thc acc uracy of t he solu tion is improvcd by d ec reasin g t he mesh s ize used for t hc nLln~erical in tegration , wh ich is cqu ivalent to in creasing t he size of t hc large g uide in the wa veg Llldc model.