High-Pass Filters with Round Spiral Resonators and Interdigitated Capacitors

The article deals with a microstrip high-pass filter with two identical spiral resonators and two interdigitated capacitors located on the side of the substrate that is opposite to resonators. The filter is installed on the substrate with dielectric conductivity epsilon=4.4 and thickness h=1.5 mm. The filter has cutoff frequency 1 GHz and compact sizes 60 x 40 = 2400 mm2. The structure was created with the help of 3D electrodynamic simulation program. The prototype was created with the use of a standard technique of etching printed circuit boards. Vector circuit analysis helped to achieve an experimental amplitude response curve that only slightly differs from the simulation results.