A. Design of Long line-fed antenna
It is very well known that to improve the impedance
bandwidth of a Long line-fed antenna is by increasing the
thickness of the grounded substrate. However, this leads to
several undesirable consequences. The larger contribution to
surface waves which leads to decreased efficiency of the
antenna. Another consequence of incorporating electrically
thick substrate is the width of the microstrip line feeds
increases. Figure 1 shows the geometry of an long line-fed
patch microstrip antenna on a thick, low dielectric constant
material at 5 GHz. A 30Ω microstrip feed line with a width of
4.5mm and a square patch of 15mm x 15mm are fabricated on
a 3.175mm thick Alien higgs (εr = 2) substrate.