A novel CMOS G $$_{m}$$ m -C complex filter design for multi-mode multi band wireless receiver applications

CMOS Analog Filter Design for Very High Frequency Applications

“…Thus, the −17 dB accomplished by the two circuit topologies described here is more realistic; it is not uncommon to have RF jammer filters with a notch depth barely larger than −10 dB. In terms of tunability, the filter in [29] is comparable to the SFG biquad and the FDNR; however, these work at a higher frequency. Unfortunately, none of the filters in Table 1 reported somewhere else present distortion measures (THD, I M 3 , I IP 3 ); on the contrary, the SFG biquad and the FDNR reported herein exhibits a good linearity with +15 dBm and +12 dBm IIP3, respectively.…”

“…The attained results are summarized in Table 1 along with some other state-of-the-art band-stop filters. From those, the proposals [28][29][30] report simulation results based on CMOS circuits, whereas approach [31] accounts for experimental results based on lumped resonators. The latter is the filter whose center frequency, f 0 , is the larger, closely followed by the biquad and FDNR filters presented in this work.…”

“…In addition, since acoustic-wave-lumped resonators are employed in [31], this is the proposal with the larger Q of all the filters in Table 1, at the expense of a null tunability. The applications for which the filters reported somewhere else are referred only in [29] (Bluetooth), the rest do not specify where the design efforts were directed to. On the other hand, both the SFG based and the FNDR filters reported herein are intended for the Medical Implant Communication Service (MICS), whose frequency band lies within the (402-405) MHz [25].…”

“…This was expected since a higher filter order with ripple in the bandpass renders a higher selectivity; however, the reached selectivity (Q = 20) of the proposed architecture is a good quality factor for a biquad, even though the NAM based biquad in [28] reports a Q of 50 for a rather low frequency of operation f 0 = 2 KHz. A Q = 20 was also achieved in [29]; nevertheless, a third order approach was used and hence the circuit possesses a steeper slope (20 dB/Dec sharper). Otherwise, the notch depth reported in [28][29][30] is optimistic; even with a very narrowband like those in [31], the achieved rejection barely surpasses the −20 dB.…”

“…A Q = 20 was also achieved in [29]; nevertheless, a third order approach was used and hence the circuit possesses a steeper slope (20 dB/Dec sharper). Otherwise, the notch depth reported in [28][29][30] is optimistic; even with a very narrowband like those in [31], the achieved rejection barely surpasses the −20 dB. Thus, the −17 dB accomplished by the two circuit topologies described here is more realistic; it is not uncommon to have RF jammer filters with a notch depth barely larger than −10 dB.…”