J.Semicond.30(11) Zou Liang et al. Table 3.Summary of the measurement results Parameter Value Technology 0.18 um CMOS process Supply voltage 1.8V Power consumption 4mA×1.8V=7.2mW Area (for both I &O channels) 1.03 x 0.93 mm2 (Filter core) 0.3 x 0.25 mm2 (Tuning circuit) _3 dB frequency 2.5,3.3.5.4MHz 5,6,7,8MHz Pass-band ripple @2.5,3.3.5,4 MHz <1dB @5,6.7.8MHz <2dB Attenuation 20 MHz >60dB Stop-band >80dB In-band group delay variation with different cut-off frequencies 120-300ns In-band IM3 Input power-11 dBm (f-3dB=8 MHz,fsignal =2 MHz 1.5 MHz) -52dB (In-band IIP3 +15 dBm) Out-band IM3 Input power-11 dBm (f-3dB =8 MHz,fsignal =16 MHz 28 -55dB MHz) (Out-band IIP3 +16.5 dBm) Noise figure 41 dB Tuning error f_3B 4 MHz ±3% The other f-3dB ±5% Tuning time 7.68μs Table 4.Performance comparison. Reference Ref.[6] Ref.[7] Ref.[8] This work Technology 0.18 um CMOS 0.35 um SiGe BiCMOS 0.18 um BiCMOS 0.18 um CMOS Application DAB/T-DMB tuner DBS-tuner DVB-T/H tuner Supply(V) 1.8 2.7 1.8 Power consumption(mA) 4.5 13 4.3 Area(mm2) 1.395 0.5 2.86 1.03 Filter orders 8 7 5 8 Cut-off frequency (MHz) 1.58 4-40 1.92 1.6-15 Stop-band attenuation (dB) 65 43 64 80 In-band IIP3 (dBm) +4.6 +10 +11 +15 Hikr4 12.80 MHz Ref -58 dBa Atten 10 dB -77.498c®a 5.Conclusion 4MHz An eighth order active-RC filter with automatic fre- quency tuning for DVB tuner applications is proposed in this paper.The programmable cut-off frequency is tuned using switched-resistor arrays and switched-capacitor arrays,thus it A12MH他3 can cover all the DVB-T/H protocols and is suitable for both 孕MH些8 low-IF and zero-IF architectures.Frequency response mea- surements show +5%tuning precision and 60 dB frequency attenuation at 20 MHz.This will be useful to alleviate the re- quirements of the following VGA and ADC and reduce the ef- Center 15.50 MHz Span 29 MHz R5B酬51h VBH 51 kHz Sweep 42.52 ms (601 pts) fect of out-band blockers.The results of two-tone testing show Fig.16.Measured out-band IM3. -52 dB in-band IM3 and-55 dB out-band IM3 with-11 dBm input power.The proposed filter circuit,fabricated in a SMIC performance of the proposed filter is summarized in Table 3, 0.18 um CMOS process,consumes only 4 mA current with and a performance comparison is given in Table 4. 1.8 V power supply. 115002-8J. Semicond. 30(11) Zou Liang et al. Table 3. Summary of the measurement results. Parameter Value Technology 0.18 µm CMOS process Supply voltage 1.8 V Power consumption 4 mA × 1.8 V = 7.2 mW Area (for both I & Q channels) 1.03 × 0.93 mm2 (Filter core) 0.3 × 0.25 mm2 (Tuning circuit) –3 dB frequency 2.5, 3, 3.5, 4 MHz, 5, 6, 7, 8 MHz Pass-band ripple @ 2.5, 3, 3.5, 4 MHz @ 5, 6, 7, 8 MHz < 1 dB < 2 dB Attenuation @ 20 MHz @ Stop-band > 60 dB > 80 dB In-band group delay variation with different cut-off frequencies 120–300 ns In-band IM3 @ Input power –11 dBm (f−3dB = 8 MHz, fsignal = 2 MHz & 1.5 MHz) –52 dB (In-band IIP3 +15 dBm) Out-band IM3 @ Input power –11 dBm (f−3dB = 8 MHz, fsignal =16 MHz & 28 MHz) –55 dB (Out-band IIP3 +16.5 dBm) Noise figure 41 dB Tuning error @ f−3dB 4 MHz @ The other f−3dB ±3% ±5% Tuning time 7.68 µs Table 4. Performance comparison. Reference Ref. [6] Ref. [7] Ref. [8] This work Technology 0.18 µm CMOS 0.35 µm SiGe BiCMOS 0.18 µm BiCMOS 0.18 µm CMOS Application DAB/T-DMB tuner DBS-tuner — DVB-T/H tuner Supply (V) 1.8 5 2.7 1.8 Power consumption (mA) 4.5 13 4.3 4 Area (mm2 ) 1.395 0.5 2.86 1.03 Filter orders 8 7 5 8 Cut-off frequency (MHz) 1.58 4–40 1.92 1.6–15 Stop-band attenuation (dB) 65 43 64 80 In-band IIP3 (dBm) +4.6 +10 +11 +15 Fig. 16. Measured out-band IM3. performance of the proposed filter is summarized in Table 3, and a performance comparison is given in Table 4. 5. Conclusion An eighth order active-RC filter with automatic fre￾quency tuning for DVB tuner applications is proposed in this paper. The programmable cut-off frequency is tuned using switched-resistor arrays and switched-capacitor arrays, thus it can cover all the DVB-T/H protocols and is suitable for both low-IF and zero-IF architectures. Frequency response mea￾surements show ±5% tuning precision and 60 dB frequency attenuation at 20 MHz. This will be useful to alleviate the re￾quirements of the following VGA and ADC and reduce the ef￾fect of out-band blockers. The results of two-tone testing show –52 dB in-band IM3 and –55 dB out-band IM3 with –11 dBm input power. The proposed filter circuit, fabricated in a SMIC 0.18 µm CMOS process, consumes only 4 mA current with 1.8 V power supply. 115002-8