Quad-Band Microwave Antenna Integrated with the mm-Wave band for Internet-of-Thing Applications

This paper presents the design and analysis of an integrated microwave and millimeter-wave antenna. The antenna offers four distinct brands in the microwave band spectrum while an additional band in the mm-wave band is also achieved. The antenna structure is inspired by a triangular quarter-wave monopole antenna which is then loaded by five stubs of different lengths to achieve the resonating bands of 2.45 GHz, 3.5 GHz, 5.5 GHz, and 7.5 GHz, and 28 GHz, respectively. Two additional stubs are also placed on the back side of the antenna and shorted using vias with stubs on the topside to overcome the narrow band at lower resonance. The optimized antenna covers the band spectrum of 2.37 – 2.65 GHz, 3.25 – 3.85 GHz, 5.0 – 6.1 GHz, and 7.15 – 8.5 GHz, 23 – 31 GHz having a peak gain of > 2.5 dBi, and > 6.5 dBi in the microwave and mm-wave bands, respectively. The compactness of size, pentaband operation along with high gain makes the proposed work a potential candidate for Internet-of- Things applications, especially for an indoor scenario for smart houses.