Miniaturized UWB bandpass filters integrated with notch filters using a silicon-based integrated passive device technology

This paper reports on the implementation of miniaturized UWB filters with low loss, steep rejection, and spurious-free response on a silicon substrate. A UWB filter is demonstrated with an insertion loss of less than 1 dB, 3 dB bandwidth of 7.25 GHz, attenuation of more than 30 dB in both the lower (10 MHz-2.6 GHz) and the upper (12 GHz-20 GHz) stop-bands, occupying only 2.9 mm × 2.4 mm of die area. In addition, a novel design is proposed for the implementation of a narrowband notch filter, which can be integrated with UWB bandpass filters for rejecting strong in-band interferences. A UWB filter integrated with a notch filter is presented having a total footprint of 4.6 mm × 2.9 mm. The notch filter centered at 5.285 GHz provides a maximum attenuation of 23 dB with 10 dB fractional bandwidth of 7% to reject WLAN/WiMAX interferences. The temperature stability of the notch filter is better than 0.4 % in the temperature range of -30 °C to 70 °C.