SPPs-Shared Dual-Band Antenna With Large Frequency Ratio

The operating frequency of future communication systems will cover both microwave and millimeter-wave (MMW) bands simultaneously. This paper presents a novel design of spoof surface plasmon polaritons (SPPs) structure-shared dual-band antenna with large frequency ratio, which consists of a planar open sleeve monopole antenna operating at S-band and a taper slot antenna (TSA) at K/Ka-band. In this design, the SPPs structure takes important roles in two aspects: it serves as an equivalent-lens to enhance the gain of TSA and a monopole of the planar open sleeve antenna to keep a low profile. To realize high isolation between the two antennas, a substrate integrated waveguide (SIW) and an integrated coaxial line are designed to feed the TSA and the planar open sleeve monopole antenna respectively. The SPPs-shared antenna shows an enhanced endfire gain of 13.09 dBi in the frequency range of 19.32-32.90 GHz and an omnidirectional gain of 1.06-2.92 dBi over the range of 2.23-3.69 GHz, keeping a compact size. The large frequency ratio of 10.8, low profile and the wide operating bands in both lower and upper frequency ranges can meet many wireless communication applications. Reasonable agreement between the measured and simulated results is observed.