抑制共模噪声的SIW 平衡馈电差分缝隙天线阵*

提出一种利用差分天线在共模激励和差模激励下方向图不同来抑制共模噪声的方法,并基于该理论 设计了6×6 平衡馈电差分SIW 缝隙天线阵进行验证。该天线由6个宽边纵向SIW 缝隙天线子阵列组成。辐射缝隙 被设计为只在差模激励下辐射,达到抑制共模信号的目的。每个天线子阵采用平衡差分馈电方式,使用两个1分6 梳状功分器将6个子阵同时激励。整个天线使用标准PCB 工艺加工,为了测试共模和差模激励,分别设计了带有 180°相移的功分器和T型功分器用来生成差模和共模信号。在差模激励下,天线的最大增益为20.2dBi,S11幅值小 于-10dB 带宽为7.2%(39.6 ~43.8GHz),在共模激励下天线的最大增益为10.1dBi,在整个工作频段内S11幅值大于 -7dB。仿真和实验结果验证了该结构的SIW 缝隙天线对差模信号能够有效地辐射而对共模信号进行抑制。

Balanced Fed Differential SIW Slot Antenna Array for Common-Mode Noise Suppression

A theory of common-mode noise suppression through the radiation pattern distinction of differential antenna excited in common-mode and differential-mode is proposed. A 6×6 balanced fed differential slot antenna array based on this theory is designed and fabricated for verification. The proposed antenna array consists of 6 longitudinal slot sub-arrays, and each sub-array has 6 radiating slots. The slots are set to radiate effectively only in differential-mode to suppress common- mode noise. Balanced differential feeding scheme is introduced to excite each sub-array from its both terminals with equal amplitude but out of phase. Two 6-way power dividers are used to unit sub-arrays in a shunt form and ensure the balanced feeding simultaneously. The antenna array is fabricated on standard PCB process. A divider with 180°phase shift and a T- shaped power divider are designed and fabricated for the measurement. The maximum gain of the antenna array is 20.2dBi in the differential-mode, and 10.1dBi in the common-mode. And the measured bandwidth of amplitude of S11 less than -10dB for differential-mode is 7.2%, from 39.6 ~ 43.8GHz. And amplitude of S11 is larger than -10dB in common-mode. The simulation and the measurement are in good agreement. The proposed antenna has the feature that it radiates efficiently in differential-mode, while suppresses common-mode signal.