||Since the Internet of Things (IoT) and Internet of Vehicle (IoV) markets are increasing rapidly, the wireless communication system with farther transmission distance, higher data rate and information accuracy are developed for matching the requirements of the multi-input multi-output (MIMO) techniques. However, there are similar passive and active devices with the same functions consume extra area in the MIMO receiver system. In order to improve the above drawback, this thesis designed and developed a multiplex power divider replaced two traditional power dividers utilizing the surface micromachining process, and diminish the dimensions of divider for the needs of wireless communications network products.|
To optimum the performances of power divider, this thesis uses the commercial software ANSYS HFSS and Agilent ADS to analyze and extract high-frequency characteristics. The main structures in this thesis including: (i) Employ two central tapped power divider to reduce the area; (ii) Utilize suspended structure to reduce the insertion loss caused by parasitic capacitance between device and substrate; (iii) Use epoxy negative resist (SU-8 5) as a MIM capacitor dielectric layer to enhance the returns. This power divider constructed of bottom electrode, supporting posts and top electrode. The main fabrication processes including six thin-film depositions, five graphic definitions of photolithography, three copper electroplating and four etching processes.
The multiplex power divider with 2.4 GHz operating frequency and measured from 10 MHz to 5.0 GHz by network analyzer. There were two generations of the power divider in this thesis. Compare with the standard phase difference (180°), the first-generation exhibited 23.89° and -47.63°, whereas -3.14° and -4.14° in second-generation, which present well balanced output phase difference characteristics. The input return losses enhanced from -7.53 and -9.8 dB to -9.45 and -14.38 dB, which improved 46% with early. The initial generation showed the output return losses of -3.42、-5.28、-2.58 and -5.12 dB, and -10.29、-11.22、-9.62 and -11.21 dB in subsequent generation, all the output return loss characteristics improved above than 118%. Moreover, the insertion losses demonstrate -19.67 -17.58、-16.89 and -14.25 dB in previous generation, and -12.98、-9.39、-10.67 and -9.17 dB in the later generation, which enhanced more than 34%.