Modified Planar Inverted-L Antenna

A hybrid inverted-L antenna (HIL) has been shown to reduce the physical height of a square planar monopole antenna, while retaining a relatively wide impedance bandwidth and good radiation pattern characteristics. The introduction of horizontal slots in the vertical edges of the antenna cause the surface current to meander, resulting in a decrease in the lower edge frequency of the impedance bandwidth. The impact of different sizes and arrangements of slots on impedance and radiation pattern bandwidth, gain and surface current distribution is simulated using transmission line modelling (TLM). Simulated results for impedance bandwidth are verified with measurements. With other modifications these antennas are proposed for wireless and mobile applications in the 2.45 GHz and 5.8 GHz ISM bands.