Study On The Design Of Microstrip Reflectarray Antenna

With advantages of high directivity,high gain and low profile,microstrip reflectarray antenna are widely used in many fields such as high-performance radar,telematics and telemetry,which becomes a hotspot in related fields.In this paper,the miniaturized design of microstrip reflectarray antenna's feed is proposed by using a new substrate integrated coaxial line(SICL)technology.In this paper,the substrate integrated coaxial line used as the feeding network in microstrip patch array antenna design is firstly proposed and followed by the verification of SICL technique in feeding network design.Then,a microstrip reflectarray antenna with SICL technique is designed according to the background of Chinese high data rate millimeter wave wireless communication standard Q-LINKPAN-L(42.5 GHz)for long-range transmission.On basis of abovementioned work,an innovation of a SICL slot array antenna is put forward for the first time with convincing experimental testification.The corresponding research work mainly includes the following four aspects:(1)the research and design of planar miniaturized feed antennaA 2 × 2 microstrip patch array antenna operating in Q band is designed and implemented.The substrate integrated coaxial line structure is adopted to suppress the parasitic radiation caused by feeding network and reduce the radiation loss.The symmetrical and constant-amplitude improves the symmetry and stability of the antenna radiation patterns.Experimental results have validated the feasibility of the design scheme.(2)the research and design of Q-band microstrip reflectarray antennaWith the aforementioned 2 × 2 array antenna used as the feed,the reflectarray is excogitated with double-layer microstrip reflector unit used as the fundamental structure.The discrete patch unit with different phase-shifting characteristics approximates the traditional parabolic reflectarray.A compact planar reflectarray antenna with a feed of miniaturized microstrip reflectarray antenna is proposed.(Operating frequency is 42.5GHz,maximum gain is 29 dBi,maximum directivity is 30.5dBi,sidelobe level(SLL)of E-plane is-16.8dB,SLL of H-plane is-20.3,3 dB beam width is 4 ° × 4 °).(3)the research and design of a low SLL and low backlobe level patch array antennaWith the feasibility of the work verified in(1),the effective and reliable substrate integrated coaxial line is used as the elementary guided wave structure of the feeding network with Chebyshev distribution for sidelobe suppression.A Q-band 6× 6 patch antenna array is designed and implemented.(Operating frequency is 42.5GHz,SLL of E-plane is-25.5dB,SLL of H-plane is-23.7dB,the maximum gain of 19dBi).(4)the proposition of substrate integrated coaxial slot array antenna and the experimental verificationRadial resonant slot acts as the main radiating element by using substrate integrated coaxial line technique.The longitudinal radiating slot cut in the outer conductor of the substrate integrated coaxial line compose the resonant antenna array,which is more compact and the corresponding width of mode requirement is smaller than traditional waveguide slot antenna array as well as substrate integrated waveguide(SIW)slot array.A 5 × 10 substrate integrated coaxial slot array antenna is designed and measured in Ka-band.(operating frequency is 34.5GHz,E-plane SLL is-23.0dB,H-plane SLL is-32.6dB,the maximum gain is 17.9dBi).Good agreement between the experimental results and the designed values has validated the feasibility of SICL slot array antenna.