Design of the Printed Slot Antenna Using Wiggly Line With Harmonic Suppression

In this letter, a microstrip slot antenna using a wiggly line for suppressed harmonics is proposed. To eliminate unwanted radiation at harmonic frequencies, a wiggly-line band-stop filter structure applying the Bragg conditions is used. The size of the proposed slot antenna is 60 <; 40 mm². It is fabricated on a substrate with a dielectric constant of 2.5 and thickness of 0.508 mm. The center frequency of the proposed antenna is 2.4 GHz, WLAN bands. The measured return loss is near 0 dB, and the measured radiation pattern of the slot antenna with wiggly line shows -15 dB suppression at 7.3 GHz, the third harmonic frequency. From the results, the proposed antenna has novel suppression characteristics in the harmonic frequency band.