相控阵T/R组件中功放自激检测电路设计与实践

Design and Practice of Self-excitation Detection Circuit for Power Amplifier in Phased T/R Components

固态相控阵雷达由于其阵面上组件弱故障率的特点,在现代雷达中大量应用。随着新型功率器件横向扩散金属氧化物半导体(LDMOS)场效应管和氮化镓(GaN)的广泛应用,其相对于硅(Si)双极器件容易自激的问题也日益突出,使得阵面存在极大的隐患。文中从自激产生的原理和危害入手,介绍了两种适合于阵面应用的自激检测电路。第一种为电流检测法,根据发射通道工作电流的变化判断,该方法只能检测出静态时出现自激故障的通道;第二种为脉宽检测法,根据开关控制信号和功率检波的时序关系进行判断,可以实现实时检测。在实际工程中可针对不同使用要求进行应用。

Solid phased array radars are widely used for the advantage of allowing a few components don＇t work. Laterally diffused metal oxide semiconductor （LDMOS） and gallium nitride （GaN） power devices are widely used in solid phased array radar re- cently, but compared with Si power devices they are easy to be self-excited. The solid phased array will work at risk because of self-excitation. For the principle and risk of self-excitation, tow methods of self-excitation detection are introduced in this paper. The first method is current detection, which is based on the change of the working current of the transmission channel. This method can only detect the self-excitation channel at static state. The second method is pulse width detection method, which is judged ac- cording to the timing relatioship between the switch control signal and power detection. This method can achieve real time detec- tion. So the suitable method can be chosen based on the actual requirement of radar.