Design And Production Of X Band Microstrip Array Antenna On Airborne Radar

Nowadays the airborne radars are mostly phased array radars, which use phasedarray antennas. Phased array radar has the characteristics of forming a multiple transmitand receive beam and rapidly changing shape and direction of the antenna beam, it has aparticular advantage in observing, following, marking and determining the targets. So ithas the potential to increase radar range. Phased array antenna that largely determinedthe performance of radar systems and even aircraft avionics system has developed intoan important direction in phased array radar. Thus, it is necessary to develop phasedarray radar antenna which has a smaller size, higher reliability and easier integration.Based on the above-mentioned background, on the base of microstrip antennatheory, antenna array theory, and phased array theory, combined with theelectromagnetic simulation software, design of the single-layer X-band antenna arrayand double-layer parasitic microstrip array antenna was presented in this thesis. Firstly,according to the indicators a4×4array antenna were designed on the substrate of2.2.the array antenna used double-layer dielectric substrate to increase the bandwidth,achieved circular polarization by square patch with notching, realized equal amplitudeand same phase feed by microstrip feed network, the array antenna samples wereprocessed by lithography. The array antenna samples was tested, the bandwidth of4×4array antenna sample was500MHz, and the gain was16dB,thus the research is correctand reliable. Then on the substrate of6.15the single-layer microstrip4×4and8×8array antenna was designed, the measured bandwidth were300MHz and the measuredgain were14dB and18dB. We find that the array antenna doesn’t has a good effect onthe bandwidth. Then we designed double-layer2×2and4×4array antenna based onthe single-layer above, the2×2array got a bandwidth of1.2GHz, and the gain was11dB. Compared double-layer parasitic microstrip array antenna to the single-layerantenna array we can find that although multi-layer parasitic microstrip array antennahas a good effect on broadening the bandwidth, it still need further optimization toincrease the gain and improve the axial ratio, far-field radiation pattern and otheraspects. And then the LTCC technology was introduced following, at the same tine we designed a single-layer2×2array antenna on LTCC, which has great prospect in future.At last, combined with the theory of phased array antenna and the thought ofsampling the antenna model, we come up with the new structure of the method ofcombining of series and parallel feeding, which will greatly decrease the cost. We putout this design and find its electromagnetic performance is very good, and it has smallerarea, which meets the miniaturization of antennas.