III. Gm-C Filtering - Epublications - Université de Limoges
III. Gm-C Filtering - Epublications - Université de Limoges
III. Gm-C Filtering - Epublications - Université de Limoges
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It is worth highlighting that FOM1 is the highest for the Rauch filter. Compared to the<br />
literature, the <strong>Gm</strong>-C filter <strong>de</strong>signed with the MGTR technique also shows a high FOM1.<br />
Hence, this means that the Rauch filter exhibits the best RF performances versus selectivity<br />
tra<strong>de</strong>-off all over the frequency tuning range.<br />
When taking into account the power consumption, the proposed <strong>Gm</strong>-C filters shows<br />
the best figure. However, process issues when implementing this solution on silicon may<br />
strongly <strong>de</strong>gra<strong>de</strong> the measured results. Reference [VI.1] and the Rauch filter then present<br />
comparable FOM2 results. The Rauch filter is optimized in terms of noise and linearity<br />
whereas the filter in [VI.1] is optimized for low power consumption. Besi<strong>de</strong>s, it has been<br />
chosen a 3.3V supply for the Rauch to enhance the input power of the filter while keeping the<br />
specified performances. With a 1.2V supply, this input power is then reduced.<br />
Future improvements of the <strong>Gm</strong>-C would consist in working on the <strong>Gm</strong>-cell linearity<br />
versus noise tra<strong>de</strong>-off. Perspectives on the Rauch filter mainly concern the improvement of<br />
the operational amplifier <strong>de</strong>sign in or<strong>de</strong>r to increase the bandwidth above 30dB voltage gain.<br />
Conclusion and Perspectives<br />
Two fully active frequency tunable bandpass filters have been simulated, and one of<br />
them measured. The results presented all along this PhD thesis open the perspective of the full<br />
integration of the silicon TV tuner over at least the first two octaves of the VHF band, leading<br />
to the emergence of the first fully-integrated silicon TV tuner.<br />
An encouraging perspective for future <strong>de</strong>velopments is the study of N-path filters<br />
which exhibit a wi<strong>de</strong> tuning range for high RF performances and high selectivity. However,<br />
these topologies may require the modification of the front-end architecture of the tuner to be<br />
used. This may involve important changes on the specifications of each block constituting the<br />
front-end architecture to finally allow reaching targeted tuner NF and harmonic rejection for<br />
instance.<br />
Reference<br />
[VI.1] Y. Sun, C. J. Jeong, I. Y. Lee, J. S. Lee, and S. G. Lee, “A 50-300-MHz low power<br />
and high linear active RF tracking filter for digital TV tuner ICs,” presented at the<br />
Custom Integrated Circuits Conference (CICC), 2010 IEEE, 2010, pp. 1-4.<br />
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