The Study Of Substrate Integrated Gap Waveguide Technology

With the development of wireless communication technology,the applications of microwave and millimeter wave in high-frequency communication systems is more extensive.The operating frequency,however,is above Ku band.The traditional microstrip line has the problem of radiation loss and surface wave,which is easy to cause large transmission loss.In order to realize the microwave and millimeter wave circuits at high-frequency,a planar substrate integrated waveguide（SIW）with printed circuit board（PCB）printing technology is proposed.SIW is able to design the devices working at high-frequency microwave.SIW is transmitted the transverse electric（TE）modes,The SIW,however,will induce the loss when integrated with the circuits of transverse electromagnetic（TEM）mode.A planar gap waveguide（GW）technology for transmitting quasi-TEM mode is proposed,which is easy integrated with the circuits for transmitting TEM modes.But the GW technology has some weakness,such as large size,heavily and highly fabricated cost,etc.To solve the aforementioned problems,a fully printed substrate integrated gap waveguide（SIGW）technology is proposed.The technology of SIGW is developed from GW technology.The gap layer of the GW is air,and the SIGW is made of stable substrates plate as the gap layer.Also,the electromagnetic band gap（EBG）of the SIGW is formed by a periodic metal vias in the substrates,and a metal layer is plated on one side of the substrates.The substrates forms a perfect magnetic conductor（PMC）structure,which can effectively prevent internal electromagnetic leakage and external electromagnetic interference.Last,fully substrate integrated packaging technology is proposed based on SIGW,and a packaged lowpass filter and a SIW bandpass filter are designed to verify the practicability of the technology.The microwave devices using SIGW technology and fully subatrate integrated technology are presented as follows:（1）The SIGW packaged microstrip line is operated at C/X/Ku band.Also,the packaged straight and bending microstrip lines are discussed,respectively.The experiment test shows that the packaged straight microstrip line is operated at 6.5-24GHz,and the packaged bending microstrip line is operated at 8-22 GHz.（2）The 7^th-order dual-band self-packaged SIGW filter is designed for operating at Ku and K bands.The experiment tests shows that the filter has a bandwidth of 1.4GHz at a center frequency of 15.3 GHz,and also a second passband with bandwidth of 0.5 GHz occurs at a center frequency of 25.6 GHz.（3）Based on the SIW and SIGW technology,the 5^th-order self-packaged broadband bandpass filter,is designed by enhancing the SIW electrical coupling.The filter is operated at Ku and K bands.The experiment tests shows that the filter has a bandwidth of 8 GHz at a center frequency of 18.9 GHz with two transmission zeros（TZs）at 13.7 GHz and 18.9 GH.（4）By studying the effcts of SIGW-PMC structure on the SIGW circuit,a high selective and wide stopband 7^th-order passband self-packaged filter is designed.The filter has fabricated with 1 mm and 1.2 mm top layers respectively.The measured results for the 1.0 mm top layer show that the filter has a 3.1 GHz bandwidth centered at 17 GHz,and two TZs at 15 and 20.2 GHz.As for the 1.2 mm top layer,the filter has 2.8 GHz bandwidth centered at 16.8 GHz,and two TZs at 14.9 and 19.4 GHz.（5）Based on the study of SIGW,the fully substrate integrated packaging technology is proposed.The technology can effectively package microwave circuits below Ku band.The feasibility of the technology is verified by designing a lowpass filter operated below C band and a SIW filter operated at Ku band.