<Abstract>

In today''s mobile communication market, the telecommunication corporations have begun their competition due to the development and remarkable advancement of 5G technologies. Many smartphone users show much interest in these new technologies, but problems are emerging one by one to paint a different picture from the future of 5G that people dream of. The telecommunication corporations advertise that their 5G services are available around the nation, but they are locally limited only to Seoul and some parts of its metropolitan region. Some researches have reported that 5G was slower than LTE even in the areas where it was available based on performance measurements. Many telecommunication corporations have made efforts to solve this problem by building a lot of base stations to establish a nationwide 5G network service and supplementing the slower speed of 5G that users raised complaints about by one technology after another. This study chose the frequency range of 3.5GHz used to build a nationwide network service as a way to solve communication-related issues in restricted areas for 5G service. The study also proposed a solution to the slower speed of 5G even in areas where the service was available by adding the LTE frequency range of 1.8GHz based on a judgment that the LTE network should be available in areas where 5G communication was impossible with the LTE network but communication was definitely needed. The investigator designed and built an antenna with these two frequency ranges to solve the problems.
An antenna was first designed with the CST Microwave Studio 2014 program. The microstrip antenna type was chosen for its convenient design on the program and its advantages for broadband and miniaturization. Judgments were based on many different result values at the simulation stage to design a proper antenna, and they led to the completion of an antenna designed in the way that was intended by the investigator. A PCB manufacturer made the designed microstrip antenna, and it was measured in input return loss, VSWR, and Smith Chart with the S-Parameter Network Analyzer. The measurements were compared and analyzed with the result values at the simulation stage. The comparison and analysis results show that there were no big differences between its measurements and result values and that it met each of the design criteria. Finally, the study raised a need for additional research on the frequency range of 28GHz for low-latency super-fast 5G service. Follow-up study will design and make a 28GHz antenna and combine it with the antenna from the present study.