Array Antenna Design And Research Of Nonlinear Calibration Technology

Antenna usually is expected to be embedded in the body of aircraft for good aerodynamic configuration and radar stealth in radar system.In other words,antenna need to be conform with carrier.However,the radiation scope of antenna often covers the normal direction of aircraft's surface only,and little radiation in the tangential direction.What's more,front-back ratio of array antenna is also important for good anti-interference ability.According to design target,a conformal microstrip antenna which is applied to high speed aircraft is designed in the article.Microstrip yagi antenna is chosen as the element.Then,particle swarm optimization algorithm(PSO)is used to synthesize the pattern of array.In the end,the radiation leak of feed network is study emphatically.On the other hand,calibration is important for ensuring the performance of phased array antenna.On the basis of predecessor's work,some improvement for the rotating-element electric field vector method(REV)is presented in this paper,including calibration accuracy and test speed.1.The influence of excitation error for patternAs all we know,excitation error for pattern can affect array's pattern.Different errors(amplitude error,phase error,amplitude and phase error)are discussed.The discussed results show that excitation error has a strong impact on pattern.2.REV based on fast Fourier transform(FFT)Continuous curve can be obtain from discrete results by FFT.The error of phase shifter and noise can be reduced by introducing FFT into REV.The simulate result proves the effectiveness of this method.3.REV based on mutual coupling between elementsCalibration online is very important for array,because phased array can be calibrated after installed to carrier,instead of taking down the array from carrier to test.Mutual coupling calibration and REV is combined in this part,which makes test more convenient.4.Phase measurement method based on cosine lawElectromagnetic field in all phase status need to be measured in traditional REV method,which will spend too much time.In contrast,two phase status just needed in the new method,which will save some time.