zero mask

The result shows that the groove depth and duty cycle error of phase mask must be controlled within the range of| Δ h| < 38nm and| Δ f| < 0.11 respectively in order to make the zero order diffraction efficiency less than 5%.

分析表明，为使零级衍射效率小于5%，相位掩模的刻槽深度和占空比制作误差必须控制在｜Δh｜＜38nm和｜Δf｜＜0.11的范围内。

The Binary phase shift keying ( BPSK) and Mary amplitude shift keying ( MASK) are widely used in radar systems, their elliptic covariance do not equal zero, are noncircular signals.

二进制相移键控（BPSK）和幅度调制（MASK）等信号是雷达系统中常用的信号，这种调制信号的椭圆协方差矩阵不为零，被称为非圆信号。