A miniaturized high isolation printed diplexer model based on band pass filter technique for 4G-LTE/5G-Sub 6 GHz applications

Abstract

Abstract This paper presents the design of a high isolation miniaturized compact diplexer model based on Band-Pass Filter technique, which is intended especially for a lower band [1.7 GHz to 1.9 GHz] fixed for 4G-LTE and a higher band [3.4 GHz to 3.8 GHz] fixed for 5G Sub-6 GHz. The designed diplexer is very compact with an overall size of 11× 36.49 mm2. The proposed design method is implemented by directly combining two band pass filters (BPFs) with separated electric and magnetic coupling distribution and designed with planar structures on a Rogers RT/duroid 6010LM substrate with a relative dielectric constant of 10.2, which simplifies significantly the design process of diplexer. The performance of this structure is presented and discussed in terms of its important characteristics: Impedance matching, Transmission losses and Isolation. Good agreements between simulated and measured results are achieved, which successfully verifies the proposed design method.