A Low-Loss, Low-Cost, All-Metal Integrated Filtering Crossover Using Hybrid Mode Resonators

In this letter, a novel filtering crossover based on metal integrated suspended lines (MISLs) technology is proposed. This design features an all-metal structure, achieving low loss characteristic. Rectangular metal patch resonators working at hybrid TEM mode and TE102/TE201mode are used for the design of filtering crossover. Slots as coupling windows between TEM and TE102are exploited, then bandwidth and isolation can be controlled flexibly. By adjusting the frequency ratio of TEM mode against harmonics, wide stopband can be achieved successfully. To validate the proposed filtering crossover, a two-channel prototype operating at 7.85 GHz is designed and fabricated with the minimum insertion loss (IL) of only 0.7 dB, and the measured results are in good agreement with simulated data.