Research On Phase-magnitude Consistency Of Feeding Transmitter Array In S Band Multiple-beam

Multi-beam TT&C system is a system relying on phased-array technique, whichrealizes tracking, ranging, TT&C of objects and data transfer. The research ofmulti-object TT&C with active array antenna and multi-beam TT&C with phased-arrayhas an important meaning and nice application foreground. Transmitter array module isthe core of a multi-beam TT&C system, whose performances of multi-beam forminginfluence the ability of multi-object TT&C directly.It has a strong relationship between amplitude-phase consistency of transmitterarray module and beam direction accuracy, level of side lobe, gain of the beam forming,size of the array. Recur to high beam direction accuracy, low side lobe of beam and highgain of beam forming, it will improve system’s EIRP, swell the distance of the spaceTT&C and enhance the ability of anti-interference. It also will reduce the size of array,cut down the cost of equipment and improve the reliability in the same EIRP byapplying good amplitude-phase consistency modules.Through the deep research of phase-magnitude inconsistency and theunderstanding of the theory on transmitter array, this paper introduces a phase shifterbased on vector synthesis which improves the accuracy of phase controlling. Themagnitude-phase inconsistency of the solid state power amplifier influences theconsistency of transmitter array mainly. This paper analyses the main factors whichinfluence the magnitude-phase inconsistency of the solid state power amplifier througha lot of tests and then shows some methods which can decrease the inconsistency:insure the same batch of power device, the consistency of grid voltage and drain voltage,the consistency of input and output match network, compensation technology and so on.According to the needs of project, we designed a phase shifter with the method ofcombining vector synthesis of wideband device and adjusting digital circuit. This shiftercovers a100MHz bandwidth of the S band and retains the precision which is less than±1.5in a wide angle between0o～360o. We also designed a continuous solid state poweramplifier whose output power is10W, magnitude inconsistency is less than±0.5dB andphase inconsistency is less than≤±5o.