Compact mm-Wave Bandpass Filters Using Silicon Integrated Passive Device Technology

In this letter, a compact bandpass filter (BPF) using integrated passive device (IPD) technology is presented, which is based on a pair of coupled-line inductors. To analyze the principle of this design, a simple but effective equivalent circuit model is provided. Using this model, it is easy to increase the number of resonators order. This structure is implemented by using a Si-based IPD process in which line inductors are located on a thick laminated organic ( $H = 40\,\,\mu \text{m}$ ) with a ground metal for shielding of lossy silicon. The minimum insertion loss of two-resonator BPF is 1.1 dB, and cascaded two-resonator structure is 2.3 dB. The size of two-resonator and cascaded two-resonator BPFs, excluding the pads, are only 0.246 $\text {mm} \times 0.44$ mm and 0.492 $\text {mm} \times 0.88$ mm, respectively.