Design of triangular slot
The basic structure of the proposed microstrap artificial model
transmission lines (ATL) with triangular slot is illustrated in Fig.
1(a). The equivalent circuit model of designed triangular slot patch
BLC as illustrate in Fig. 1(b). The circuit model consists of
combination inductors and capacitors both in series and parallel. We
included an inductor and capacitors for the splits for the metal
strip. The overall area of the
triangular slot patch was
approximated to that of the low impedance line in this case. The
related parameters can be expressed as follows[30]:
TATL = \(\left(\frac{L}{2}\right)^{2}\) (1)\(\frac{L}{2}\) =\(\sqrt{{2W}_{\text{TL}}L_{\text{TL}}}\ \) (2)
Where TATL, L, WTL, and LTL, the width and length of the base line were
ATL and TTL, respectively. In order to miniaturise the common 3-dB BLC,
we proposed a triangular slot -type artificial model transmission lines
with modified slots. This ATL was an isosceles triangular slot formed by
folding a stepped impedance line (SIL) into a right angle, as shown in
Fig.2 (a) Sex triangular slot BLC.