| Summary: | The rapid development of wireless applications has created a demand for low-cost,
compact, low-power hardware solutions. This demand has driven efforts to realize fully
integrated, “single-chip” solution systems. While substantial progress had been made in the
integration of many RF and baseband processing elements through the development of new
technologies and refinements of existing technologies, progress in the area of fully integrated
filters has been limited due to the losses (low Q) associated with integrated passive elements
in standard IC process. The work in this report focuses on the design and analysis of CMOS
based RFIC bandpass filter for center frequency of 1.90Hz. The entire design and analysis of
the filter circuit have been carried out by ultilizing Cadence IC Design Tools (version 5.033).
This report present a methodology for designing a Q-enhanced bandpass filter with active
negative resistance generator circuitry to compensate for the filter losses due to the low
quality factor of monolithic spiral inductors. The first phase of this work focus on the design
and simulation of an ideal, fully integrated second order Butterworth bandpass filter (with
-3dB bandwidth of 200MHz centered at 1.9GHz, corrensponding to the CDMA2000
Standard) ultilizing Cadence IC Design Tools with Silterra 0.18um Design Kit. The ideal
bandpass filter which based on the paper work calculation is first constructed by using
Silterra SMCMOS ideal component and the simulation results are observed. The ideal circuit
is then simulated by using Silterra RF component (which include all parasitic effects) to
show the actual filter performance. In the second phase of this work, a FET-based active
negative resistance circuit is developed and being added into the bandpass filter circuitry to
compensate the filter loss. With features of Cadence IC Design Tools, the filter is analyzed
and optimized to obtain the best response. The best filter design achieves ≈ 0dB of passband
gain or insertion loss while consuming 8.8mA of current from a ± 1.8V source (31.69mW).
The filter provides more than 10dB of rejection at 1.5GHz and 2.5GHz. In the filter
passband, the noise figure is 5.25dB and input return loss is -20dB. The filter response only
suffered a minor frequency shift for a wide range of operating temperature. The bandpass
filter has potential application as RF filters in CMOS integrated transceiver designs.
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