Enhancement of Antenna Gain and a Bandwidth using Frequency Selective Reflectors

We propose a new method of enhancing antenna gain and an impedance matching bandwidth at the same time using simple frequency selective side reflectors. The proposed reflectors are installed on both sides of a feeding dipole antenna, which are located at a similar height of the dipole from a ground plane. In order to accomplish our goal, we use a new anti-Fabry-Perot ( AFP) resonance mode created from an appropriate arrangement of FSRs. The anti-resonance condition is very similar to the well-known Fabry-Perot ( FP) resonance one except an additional phase delay ( or advance) of pi, which means our antenna operates in a totally different manner from conventional FP cavity antennas. Conceptually, the reflectors block waves leaking in lateral directions and send them to a boresight direction, which is helpful to increase the gain and the bandwidth at the same time. In addition, we can also enlarge a frequency bandwidth, in which the main lobe heads for the boresight direction (theta = 0 degrees).