摘要
We designed and constructed a novel,compact tri-band monopole antenna for intelligent devices.Multiband behavior was achieved by placing inverted-L shaped stubs of various lengths in a triangular monopole antenna fed by a coplanar waveguide.The resonance frequency of each band can be controlled by varying the length of the corresponding stub.Three bands,at 2.4(2.37-2.51),3.5(3.34-3.71),and 5.5(4.6-6.4)GHz,were easily obtained using three stubs of different lengths.For miniaturization,a portion of the longest stub(at 2.4 GHz)was printed on the opposite side of the substrate,and connected to the main stub via a shorting pin.To validate the concept,the antenna was fabricated on a low-cost 1.6-mm-thick FR-4 substrate with dimensions of 20×15×1.6 mm^(3).The antenna exhibited a moderate average gain of 2.9 dBi with an omnidirectional radiations over the bandwidths required for RFID,Bluetooth,ISM,WiMAX,andWLAN-band applications.These features make the antenna suitable for compact smart devices.
基金
This work was supported by the ICT R&D program of MSIT/IITP,[2019-0-00102,A Study on Public Health and Safety in a Complex EMF Environment].This work was also supported by the National Radio ResearchAgency,[Rapid measurement system for new technologyantenna].