Microstrip Interdigital Bandpass Filter
Above: This example shows an interdigital bandpass filter on er = 2.0 material with a thickness of 40 mils. Resonator conductors are 80 mils wide, and about 1465 mils long. Spacing between outer resonators is 140 mils, and spacing between inner resonators is 160 mils. Vias to ground tap opposite ends of adjacent resonators. Analysis also includes a shielded enclosure with metal lid 400 mils above the surface of the dielectric substrate.
View of the circuit in Sonnet Lite project editor. Triangles on resonators indicate locations of via connections to ground.
Surface current density (Jxy) on the microstrip filter at 1.48 GHz, at resonance. Red indicates high current density, blue is low. Current density shown is displayed by the current density viewer in Sonnet Lite.
Below: Simulated S-parameter response by Sonnet Lite. S11 (input return loss) is shown in the red graph, S21 (through parameter) is shown in the blue graph. Analysis results are for lossless metal inside a metal shielded enclosure (no radiation loss).
This analysis required 10 Mbytes at the highest frequency of 1.55 GHz. This simulation may be performed using the Registered version of Sonnet® Lite. All results and graphics shown were created using Sonnet Lite.
