Design On Planar Dual-band And Broadband Coupler

Since the beginning of the twenty-first century, with the rapid development of mobile communications especially mobile personal communications,an increasing number of wireless communication technology and communications products had came into our lives.IEEE802.11wireless local area network (WLAN) technology is greatly changed our lives.The circuit of wide variety of mobile communication technology can not be separated from power distribution and aggregation functions.The directional coupler plays an important role in those circuits.The planar structure of the directional coupler was studied in this thesis.Two kinds of models was proposed for both dual-band coupler and broad-band coupler.Each of them was designed,simulated and manufactured.The main contents in this thesis are as follows:1.A dual-band coupled-line coupler was designed in this thesis.It can work at two point of working frequency in the same time.Then the duan-band coupler was designed for two WLAN working frequency,2.4GHz and5.8GHz and the coupling coefficient is-10dB.Then it was manufactured in two structures-the broadside-coupled strip-line and the parallel coupled strip-line.The measured results were matched with simulated results.2.Two kind of broad-band coupler were designed using slotted micro-strip line,one of them had a square slot and the other one had a ellipse slot.The first one was designed for working at the band of4GHz-7GHz with-3dB coupling coefficient. The second one was designed for working at the band of4.2GHz-8.2GHz with-3dB coupling coefficient. Both of them were simulated and manufactured.In summary, the paper mainly studies the analysis and design of the dual-band directional coupler and the broadband directional coupler.Then both the dual-band directional coupler operated at WLAN band and the broadband directional coupler have been manufactured and tested.