||This thesis investigates antenna design of a compact Dual-band MIMO antenna for LTE 700/1800 and using in USB Dongle applications. Because of antenna can only occupy a quite small space in the traditional USB Dongle antenna design of the reference. So, placing multiple antenna in a compact wirless communication device, miniaturizing of antenna area becomes very important. Because of using MIMO antenna system, the distance between the two antennas must be very close to the antenna and isolation will be difficult to improve. Therefore we design a isolator to improve isolation of this antenna.|
To achieve the requirement mentioned above, we design a PIFA antenna by coupling feed. Then, two resonant frequencice of 700 and 1800 MHz were obtained by a coupling shorting strip. To make the MIMO antenna can be used to achieve the S21 standard, we design a protruded ground plane in central of two antennas. Then, by adding Ω-shaped slot design to enhance its isolation. In the case, the S21 achieves near -15 dB in frequencice of 700 and 1800 MHz for the LTE applications. The antenna portion of 16×26.5×0.8 〖mm〗^3 and overall dimension of 90×26.5×0.8 〖mm〗^3
can be easily applied in USB Dongle.
In order to meet the needs of modern bands applications, we use a structure similar to the previous chapter, and in a prominent part of the ground add a monopole slot antenna to resonant frequencice of 900 MHz, and increase the isolation by the slot design, it can be used to achieve the standard of S21. The antenna portion of 16×34.5×0.8 〖mm〗^3 and overall dimension of 90×34.5×0.8 〖mm〗^3 can be implemented using LTE 700/900/1800 tri-band antenna in the printed circuit board.