A Hepta-Band Antenna with Large Frequency Ratio for WLAN/LTE/5G Communications

A novel hepta-band antenna designed for WLAN/LTE/5G operation is investigated. In the millimeter-wave bands, two substrate integrated waveguide slot arrays (SIW-SAAs) coupled with a series of parasitic elements are integrated into the antenna, which operate in 28- and 38- GHz bands (from 27 to 29 GHz and from 36.9 to 39.6 GHz, respectively). In the microwave bands, as the substrate integrated waveguide (SIW) structure can be equivalent to a metallic strip at the frequency much lower than its cut-off frequency, the antenna composed of two SIW sections can work at two loop antenna modes and one PIFA antenna mode, which covering the LTE2300/2500/ WLAN2.4G/5G bands and 3.5-GHz band (3300-3600 MHz) for 5G mobile communications. In addition, the proposed antenna only occupies a space of 18 × 54.5 mm2 and has the advantages of large frequency ratio, simple structure and ease of integration, which makes it suitable for future mobile communication applications.