Proximity coupled microstrip patch antenna design with reduced out of band harmonics device at 2.45 GHz

An efficient proximity coupled microstrip patch antenna has been designed at 2.45 GHz. The length of the feeding line penetration and a simple rectangular slot etched in radiation element are used to reject the 2
^nd
and the 3
^rd
harmonic frequencies. The proposed antenna is well suitable for microwave wireless transmission because no input low pass filter and no via-hole connections are required, resulting in simpler and compact structures. An electromagnetic simulation has been used to optimise the antenna. The antenna gain is 6.37 dB at 2.45 GHz operating frequency. The return losses at the 2
^nd
and 3
^rd
harmonic frequencies are -0.4 dB and -0.8 dB, respectively.