High rejection BPF for WiMAX applications from Silicon Integrated Passive Device technology

We have developed a balanced band-pass filter using Silicon Integrated Passive Device (IPD) technology. The size of the filter is 2.0 × 1.3 × 0.4 mm³, which is by far the smallest filter achieving similar characteristics, to the best of our knowledge. A hybrid EM-circuit optimization scheme has been adopted for the design. Prototypes are made and measured. Good agreement has been achieved between simulated results and probed data. The measured insertion loss is 2.3 dB, the attenuation at 2.1 GHz is 24 dB minimum, and the attenuations at 2nd and 3rd harmonics are better than 35 dB. This small form-factor WiMAX filter is well suited for SiP applications to replace discrete filters, or to save large areas used to implement such filtering functions on boards.