Compact LTCC in-phase filtering power divider

In this paper, a compact in-phase power divider integrated with bandpass responses in low temperature co-fired ceramic (LTCC) technology is presented. The proposed device is composed of three coupled half-wavelength resonators and an isolation resistor. Among them, one resonator acts as the common resonator and is symmetrically coupled to the other two using multiple broadside coupling. In this way, both filtering and power dividing responses are realized. For validation, an in-phase filtering power divider centered at 5.45 GHz is designed. The size of the circuit is only 3.3 × 3.2 × 1.6 mm3.