Research And Design Of Ku Band Active Phased Array Antenna

With the development of communication technology,the research of phased array antenna has not only been confined to the military field,but also has been widely used in the fields of civil aviation early warning,public security and so on.Phased array is one of the core technologies of 5G.With the development of 5G technology,the phased array technology has been pushed to a new level of widespread application,which is the focus of research and development in various countries.Phased array technology is bound to produce more and more important impact on people's lives.Therefore,the research on phased array antenna is of great significance.In this paper,an active phased array antenna with low mutual coupling performance at large scanning angles is studied.Firstly,according to the analysis of the design requirements,the scheme of the phased array system is determined.The design process includes the design of 16×16 antenna radiation array,coupler and Wilkinson power divider.In order to realize plus-minus 60 degrees the scanning of elevation and azimuth planes without appearing the grating lobe.The problem is that the array antenna elements have small spacing and poor mutual coupling,which may cause scanning blindness spots and affect the scanning range in phased array.It can bring great difficulty to design.In order to provide more diversified choices,two schemes of dielectric horn array and printed oscillator array are adopted in this paper.By introducing non-resonant lead patch and isolation strip into printed oscillator antenna,the problem of mutual coupling and isolation between printed oscillator units of phased array antenna at large scanning angle are solved.The unit return loss of phased array antenna is less than-20dB,and the mutual coupling between antenna is less than-18.6dB.It lays a good foundation for the design of large scanning angle phased array antenna.Secondly,the sidelobe is weighted by Taylor synthesis method,the sidelode lever of the array antenna is reduced and the anti-interference capability of the phased array antenna system is improved.In the system,the internal monitoring method is used to monitor the coupling degree between measurement units.The output of sixteen antennas are fed through slot coupling series,and the power divider synthesizes the signals of sixteen calibration coupling channels in the phased array antenna radiation array.The switch controls a certain line to turn on.The output of Wilkinson power divider is the coupling signal in a certain row of a certain column.It is used to monitor the amplitude and phase of each antenna channel.It can be judged whether the antenna is working properly at the operative mode.Finally,the whole phased array antenna system is simulated and designed.The gain of the array antenna is about 29dB,and the normal beam width of the antenna is about 6.2 degrees.The coupling degree of the calibration network in the phased array antenna is between 35±2dB,and the coupling degree from total port of the monitoring network to the antenna unit is between 48±2dB after the one-divided-to-sixteen Wilkinson power divider is connected.The elevation and azimuth planes are scanned to ±60 degrees,and the gain decreases within 5dB,which satisfies the requirements of the index very well.It lays a good foundation for the future design of phased array antenna is integrated by the monitoring network.