强耦合干扰对消系统接收通道噪声系数分析北大核心CSCD

在一般无源干扰对消方法的基础上,提出了用于抑制强耦合干扰的改进无源对消方法。该方法通过改变接收通道对消耦合器接法实现。推导了对消系统接收通道的噪声系数公式,计算了典型通道数下改进无源方法和有源方法的对消系统接收通道噪声系数;建立了单通道对消系统实验平台,测试了改进无源方法和有源方法的对消系统接收通道噪声系数。结果表明:不同对消通道增益裕量时,最优的改进无源方法相对有源方法的噪声系数均有较大改善,改善量接近放大器的噪声系数;在固定耦合器耦合度情况下,改进无源方法的噪声系数改善量降低,但在实际工程条件下仍优于有源对消方法的噪声系数。

Analysis of Noise Figure of Strong Coupling Interference Cancellation System Receiving Channel

Based on the general passive interference cancellation method, an improved passive cancellation method is proposed to suppress the strong coupling interference. The method is realized by changing the receiving channel cancellation coupler connection method. The noise figure(NF) formulas of the receiving channel of the interference cancellation system (ICS) are derived, and noise figures of the receiving channel of ICS with improved passive method and active method under typical channel number are calculated. The experimental platform of a single channel cancellation system is established. Noise figures of improved passive method and active method to the receiving channel are tested. The results show that the NF of the optimal improved passive method is much better than that of the active method when the gain margin of the cancelling channel is different, and the improvement is close to the NF of the amplifier. Under the fixed coupler coupling degree, the NF improvement of the improved passive method is reduced, but it is still better than the NF of the active cancellation method in practical engineering conditions.