液晶的介电各向异性分布对液晶微带线特性的影响

Influences of distribution of LC dielectric anisotropy on properties of LC microstrip line

基于向列液晶的微带传输线模型，研究了其模场解和1～100 GHz频段内传输特性，采用有限元法较为精确和全面地分析了各向异性非均匀分布的液晶介质对微带传输线模场解和S参量的影响，并且分析了微带电极上施加偏置电压对该传输线S参数的影响。仿真结果表明：该微波传输线模型的回波损耗在考虑液晶的介电各向异性非均匀分布时比传统仿真方法所得结果更低，随着偏置电压在一定范围内连续增大其S参数连续变化，同时谐振频率连续移动，并且这种精确的分析方法计算得到的谐振频率点的偏移量相比传统分析方法修正误差2.4 GHz，这为液晶微波可调器件的进一步研究奠定了理论基础。

The transverse mode and transmission properties in frequency region of 1-100 GHz of a microstrip transmission line model based on nematic liquid crystal （LC） were studied. The influences brought by the distribution of dielectric anisotropy of liquid crystal on the solution and S-parameter of microstrip line were researched through the finite element method accurately and comprehensively, as well as the influences of the bias voltage. Simulation results indicate that the distribution property reduce the echo loss of microstrip line, which is obtained in consideration of the distribution of dielectric anisotropy of liquid. Besides, the S-parameter changes continuously since the voltage between the strip and the gound gradually increases while the resonant frequency moves the same way. Moreover, this accurate method can amend the motion of resonant frequency by 2.4 GHz, compared with the results obtained by those methods in the past. This paper provides a theory basis for researches in the field of LC microwave devices.