Dual-Band Antenna With Wideband Harmonic Suppression Based on Dual-Function Slot Structure

A dual-band antenna with wideband harmonic suppression based on dual-function slot structure is presented for the future microwave and millimeter-wave communication system in this letter. In the low-frequency band, the slot serves as the radiator, and both two parasitic patches and four slot-stubs are also introduced in the slot to increase the bandwidth. In the high-frequency band, this slot works as the feeding structure, which excites the 2 × 4 millimeter-wave patch array. Meanwhile, the wideband harmonic suppression between dual frequency bands is achieved by loading both four open-stubs on this slot and a T-stub in this slot. A prototype is fabricated and measured to validate the design, which covers a dual band of 5 and 27 GHz. Their measured -10 dB relatively impedance bandwidth is 21.9% and 13.7%, respectively. Moreover, the measured reflection coefficient is higher than -1 dB and the measured gain is lower than -10 dBi from 7 to 21.5 GHz, showing the characteristic of good harmonic suppression.