Tunable Q-enhanced LC dual-band filtering at microwave frequencies in 0.13 Am SiGe BiCMOS

Abstract

This paper presents an active Q-enhanced LC dual-band band-pass filtering approach using parallel synthesis techniques at X-and Ku-bands in 0.13 ?m SiGe BiCMOS technology. By employing two independently tunable parallel LC-tanks with either in-phase and out-of-phase addition, independently tunable dual-band filtering is achieved. For higher out-of-band (OOB) attenuation, subtraction of the two 2 nd -order bandpass filter is implemented. The two bands are independently tunable in terms of Q and center frequency. The dual-band filter at 9.7 GHz and 13.9 GHz achieves a normalized dynamic range of 165-154.5 dB.Hz with an OOB attenuation of >50 dB below 3 GHz. In between the two bands, the attenuation is 22 dB when the two passbands have 200 MHz bandwidth each. The total group delay is 0.8 ns and 1.9 ns for Q of 20 and 50, respectively. The filter achieves better OOB rejection with wider band channels at X-and Ku-bands compared with state of the art integrated filters. The filter consumes 115-130 mW of DC power. The core die area is 0.53 × 0.7 mm 2 .