Novel compact diplexer using net-type resonators

In this paper, a microstrip diplexer with compact size and good output isolation is proposed. This diplexer consists of two types of folded net-type resonators which have the same size but different resonance frequencies for composing the diplexer. Good selectivity and stopband suppression properties are achieved. For validation, the diplexer operating at 2.45/3.55 GHz is implemented and the area of the circuit is only 13.2mm × 16.7mm or 0.17λg × 0.22λg.