Frequency Reconfigurable SRR Filter Based on Nematic Liquid Crystal for Microwave Applications

A microwave frequency continuously electrically tunable split ring resonator (SRR) band-pass filter using nematic liquid crystal (LC) is proposed in this paper. The nematic liquid crystal is used to obtain the frequency shift of microwave band by changing its permittivity at room temperature (20°C-2S
^∘
C). The permittivity is controlled by the bias voltage. The simulation results show that 890 MHz offset is achieved. The proposed filter has many advantages, such as continuously electrically tunability, miniaturization, low tuning voltage, etc. Therefore, a great potential of such a filter has been shown for use in modern microwave communication applications.