| Recently,the data volume of new interconnection services has exploded,and the data interaction needs to be comparable to the data rate of optical fiber.The millimeter wave wireless communication system with wider bandwidth and highr transmission rate has a wide application prospect in the 5th generation(5G) and post 5G era.This thesis presents three kinds of coplanar-to-rectangular waveguide transitions to achieve the connection efficiently between millimeter wave devices based on different transmission lines and the waveguide output of the millimeter wave devices,designs multi-beam and beam-steering antennas to increase the coverage of millimeter-wave wireless communication system,and builds two high-speed millimeter-wave wireless communication system based on photoelectric combination technology and Resonant tunnel diode(RTD),respectively,The main research works of this thesis are as follows:1.Three kinds of coplanar-to-rectangular waveguide transitions and the package cavities of-UTC-PD using three different processes are presented.Firstly,we proposes two broadband coplanar-to rectangular waveguide transitions using E-plane stepped probes for D/W band applications.A window connecting to the air cavity is opened in parallel with the H plane of the waveguide,and the E plane probe is used to propagate the wave of the CPW into the waveguide.The simulated and measured results show that the transtions can cover D/W-band,and have wider impedance bandwidths of 43%and 37.8%and the insertion losses of 0.5 dB and 0.15 dB without consisering the metal and substrate losses,respectively.Secondly,a W-band broadband CPW-substrate integrated waveguide(SIW)-rectangular waveguide transition is designed.The waveguide is directly mounted on the bottom surface of the SIW.The structure is simple and easy to assemble,and the processing cost is lower using the PCB processing technology.The measured frequency range of|S11}<-10 dB ranges from 80 GHz to 105 GHz,and the relative bandwidth is 27%.Then,two configurations of the CPW-ridge-rectangular waveguide transitions for D/W band applications are proposed,which empoly chebyshev ridge waveguide impedance transformer to widen the impedance bandwidths.Among them,the D band transition can achieve 43%of impedance bandwidth,and the insertion loss is less than 0.6 dB considering the metal and dielectric losses.However,this structure needs to ensure good contact between the CPW and the ridge,which increases the difficulty of assembly.While the W band wideband contactless CPW to rectangular waveguide transition adds a matching stub over the quartz CPW to ensure the wider impedance matching and maintain a good energy transmission.The measured results demonstrate that the insertion loss is on average 1.2 dB in the 80-109 GHz frequency range.Finally,the three kinds of transitions are applied to the package cavities of UTC-PD with wire bonding,flip chip and ridge waveguide coupling,respectively.2.A W band high efficiency multi-beam circularly polarized(CP)antenna array with the groove gap waveguide(GGW)Butler matrix is proposed.First,a 4 × 4 GGW Butler matrix is designed.By composing two couplers,the improved crossover with higher port isolation is realized.Secondly,a wideband CP septum antenna element based on GGW structure is designed.Double ridge waveguide is used to achieve more compact antenna aperture.Two symmetrical septum blades filled in the widened rectangular waveguide is employed to achieve the circular polarization characteristics,and two ridges are added on the upper and lower metal plates to improve the polarization purity.Finally,a four-beam CP end-fire antenna array is achieved by combining the 4 × 4 GGW Butler matrix and 1 × 4 CP antenna array.Simulated and measured results verify that the antenna has a wider impedance bandwidth of 17.6%from 77.5 to 92.5 GHz for |S11|<-10 dB,and the coverage of the four beams is(-28°,28°),the maximum gain is 15.29 dBic,and the maximum radiation efficiency is higher than 89%.3.A novel 3D beam-steering THz antenna with the switchable graphene-based high impedance surface(HIS)is designed.The antenna consists of a switchable graphene-based HIS and a loop antenna loaded above it.By loading the graphene units under the circular patch of the HIS,the operative modes of the proposed graphene-based HIS units are expected to be controlled due to the alterable surface conductivity of the graphene.The beam direction of the antenna can be adjusted to achieve beam scanning by changing the number of high impedance state units.Due to the symmetry of the antenna,the antenna can achieve beam scanning in multiple horizontal planes,and the simulation results show that twenty-five steerable beam directions in the semi-sphere space(??0°,±5°,± 10°};?? {0°,30°,60°,90°,120°,150°})are achieved.4.Two millimeter-wave wireless communication systems are proposed.Firstly,a millimeter-wave wireless communication system based on photo-electric combination technology is builded.The OOK modulation is used.The baseband signal is carried to the optical carrier and the optical signal is converted to the electrical signal through the UTC-PD.The transmitting and receiving antennas are high-gain cassegrain antennas,and the signal received by the cassegrain antenna is directly demodulated using the detector.The experiment proofs that this system achieves a transmission rate of up to 10 Gbps and a wireless transmission distance of 1.2 kilometers.Secondly,A highly integrated wireless communication with packaged resonant tunneling diode(RTD)with rectangular waveguide output is builded.The packaged RTD exhibits an oscillation frequency of 92 GHz,while the maximum radio frequency(RF)output power is-7 dBm.Then,a miniaturized and high data rate wireless communication system with a 7 Gbps on-off keying(OOK)module using the RTD is demonstrated,and the bit error rate(BER)of the 7 Gbps is below 3.8 × 10-3. |
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