Dual-Band Bandpass Double Ground Plane Coaxial Resonators and Filters

This paper proposes a novel double ground plane coaxial resonator that allows to realize two independent coaxial cavity modes in reduced physical volume. This configuration of compact high performance filters is an enabler for multiband transmitter architectures using modern radio frequency data convertors. The proposed approach benefits from simple design and design flexibility. The benefit of the proposed approach is the ease of design and the design flexibility. The proposed filters provide the ability to control the frequency, the bandwidth, and the introduction of transmission zeros separately for each band. A number of designs are presented to demonstrate the operation principle and the performance characteristics of the proposed filters. A 2 \times 4 pole filter has been manufactured and tested with very good obtained results.