Research On Phase Array Antenna In Mid-field At Ka-band

Phased array antenna is evolved by array antenna, constituted by many of the sameradiating elements arranged according to certain rules, the amplitude and phase of each unitencourage relationships can be controlled to change the surface of the electromagnetic fielddistribution of antenna port, to obtain the desired directional radiation or reception. Activephased array antenna calibration techniques is a comprehensive technology, progressivewith the development of active phased array antenna technology and its main task is toensure that the antenna performance characteristics over the entire life cycle reliability andmaintainability of the active phased array antenna fault diagnosis, localization, performanceevaluation, calibration, complete security and maintenance.With the development of phased array radar technology, different forms bands andvarious scale phased array antenna continuously developed and applied. Accordinglyvarious calibration and measurement methods adapted also in constant development. Thispaper carried out on ka-band phased array antenna calibration method in mid-field, themain content include: research and comparison calibration method, According to amplitudeand phase errors on the antenna pattern, put forward accuracy requirements, analytical errorsources, design calibration method, Simulate the calibration process. Put forward thecontrol requirements of various error sources by analyzing the amplitude and phase errorsources to make sure that the phase array calibration process can be quickly and accuratelycarried out. Ka-band phased array owing to the higher frequency, the wavelength is only afew millimeters, so that the presence difficulties of the calibration are:(1) the spacingbetween antenna elements is very small leading to strong mutual coupling between theunits, for high requirements of the probe;(2) Calibration systems require high mechanicalerror;(3) Testing environment have a greater impact on the test results.In this Paper we introduce the research background of array antenna calibrationtechniques and its significance and technologic advances, explain the principles advantages and disadvantages of various existing phased array calibration method. Secondly, by analyzing the impact of amplitude and phase errors on antenna pattern,calculate the allowable error and propose the required precision.Then, introduce the principle of phased array midfield calibration, design ka-bandphased array calibration scheme in mid-field, design midfield calibration distance, the testprobe and various design solutions for control error, the system error control within anacceptable range by controlling error redundancy. Then design appropriate small mobileanechoic chamber for antenna mount design gives high theoretical design parameters;scanning solution designed and elaborated system software composition.Finally, electromagnetic simulation verify the calibration method, take more simplehalf-wave dipole antenna for example, the use of simulation software FEKO in mid-fieldcalibration method to simulate the case were fixed simulation midfielder single probecalibration, point by point midfielder probe mobile calibration prove Ka-band midfieldercalibration method can be implemented. And the current rotation vector (REV) simulationreduction compared with the quantitative characterization midfielder calibration method.