Design and simulation of tunable bandstop filters by integrating RF MEMS shunt switch for K-band applications

This paper represents the design and simulation of tunable bandstop filters by integrated with an RF MEMS shunt switch. The transformation of the bandpass filter to the bandstop filter is also done in this paper. The bandpass and bandstop filters are designed utilizing ECE-shaped DGS resonators within the coplanar waveguide (CPW) structure. Three different types of RF MEMS switches are proposed and investigated. The switch with low pull in voltage and better RF characteristics is considered for integration with filters The BPF exhibits an insertion loss of under 1.6 dB. It offers a relative 3-dB bandwidth of 60% and a 30-dB bandwidth of 77%. In the case of the BSF, it effectively achieves a 20 dB stop band at 20.5 GHz, maintaining a return loss of only 0.3 dB. The tunability of the filter is observed by integrating a MEMS capacitive shunt switch onto the transmission line. A pull in voltage of 4 V is achieved with a high capacitance ratio of 63.9.The simulation and parametric analysis of the RF MEMS switch is carried out by COMSOL and the RF performance of the switch, tunability of the filters are studied with the help of the HFSS FEM tools. The mechanical resonance frequency, other RF performance and tunability of the filters attained a frequency range (18–27 GHz). So the proposed switch and filters are suitable for K band applications, especially for satellite communications applications.