Wide upper stopband and nonorthogonal I/O feed dual-mode LTCC filter

A wide upper stopband and nonorthogonal input/output (I/O) feed dual-mode bandpass filter (BPF) is proposed. The BPF is implemented in a 2-layer low temperature co-fired ceramic (LTCC) substrate and the wide upper stopband is achieved using broadside parallel-coupled lines with stepped impedance feed lines. 40 dB suppression of a 2 ^nd harmonic (2f 0 ) and a prediction of 20 dB suppression up to 2.4f 0 are achieved. Furthermore, yield analysis, performance comparisons and discussions are also implemented.