本文利用第二类尖劈并矢格林函数对任意夹角的V形缝隙天线进行了矩量法计算。V形缝隙开在V形金属板上，并且由双线从中间馈电文中给出了缝隙口而场分布和天线H面方向目的理论计算结果和实验结果，两者基本吻合。文中最后给出了三种非V形弯曲缝隙的实验结果。

A new impedance boundary condition for impedance loaded dipole antennas was proposed. Therefore, one kind of new pulse antennas, such as reactance loaded antennas, can be dealt with in time domain directly by FDTD method. Some examples, such as capacitance loaded pulse antennas, were given.

When the transmit BJT power amplifier is connected to the receive BJT low-noise amplifier, a switch can be realized. Since the frequency-dependant quarter-wavelength transmission line normally used in low-cost PIN diode switches has been eliminated, the bandwidth is increased.

A new kind of leaky coaxial cable composed of an axially-slotted line covered with periodic metallic patches is proposed. The basic cable sets up a surface wave and does not radiate itself, but excites the patch apertures into radiation. The direction of the radiation field can be changed by adjusting the size and period of the patches according to the environmental application. A combined method that involves FDTD iteration and integration of the equivalent surface magnetic current is introduced in order to determine the radiation field accurately.

Frequency band and coupling loss are the two important parameters of leaky coaxial cables with periodic slots. Frequency band can be predicted by analyzing the arrangement of the slots on the outer shield of the cable, but the coupling loss is not so easy to determine by classical methods. In this paper, the finite-difference time-domain (FDTD) method is used to calculate the electric field distribution in the slot cut in the outer conductor of the coaxial cable. The dyadic Green's Function is then used to calculate the radiation field of the equivalent surface magnetic current densities. By these two methods, the coupling losses of the leaky coaxial cables with different periods, sizes and shapes of the slots can be accurately obtained. Some results in this paper were verified by the experimental results of the leaky coaxial cables designed for railway mobile communications with a frequency band of 100-500 MHz.