Wideband Tunable RF Filters for Channel Selection in Crowded Spectral Bands

It is very effective way to utilize a very wide tunable filter in co-existing multi-standards wireless communications environment. Especially, as the long term evolution (LTE) communication era has come, the multi-band coverage is one of the important features required for the RF components. In this paper, we present the frequency conversion technique, and so generate two types of RF filters which are specially designed for the superb tunable ability to support multiple wireless communication standards. With the help of a complex mixing structure, the inherent image signal is suppressed. The RF band-pass filter (BPF) and notch filter achieve 1.8dB and 1.6dB insertion losses and 18 dB and 17 dB attenuations, respectively. The quality factor show greater than 30.





References:
[1] W. D. Yan and R. R. Mansour, “Tunable dielectric resonator bandpass
filter with embedded MEMS tuning elements,” IEEE Trans. Microw.
Theory Tech., vol. 55, no. 1, pp. 154–160, Jan. 2007.
[2] I. Reines, A. Brown, M. El-Tanani, A. Grichener, and G. Rebeiz, “1.6–2.4
GHz RF MEMS tunable 3-pole suspended combline filter,” in Proc.IEEE
MTT-S International Microwave Symposium Digest, 15–20 June 2008,
pp. 133–136.
[3] N. Shigekawa, K. Nishimura, T. Suemitsu, H. Yokoyama, and K.
Hohkawa, “SAW filters composed of interdigital schottky and ohmic
contacts on AlGaN/GaN heterostructures,” IEEE Electron Device Lett.,
vol. 28, no. 2, pp. 90–92, Feb. 2007.
[4] F. Shiba, M. Yamazaki, O. Iijima, and H. Yatsuda, “GPS SAW filter
using a wafer level technique,” in Proc. IEEE Ultrasonics Symposium,
28–31 Oct. 2007, pp. 937–940.
[5] A. Yoshizawa and Y. Tsividis, “A channel-select filter with agile blocker
detection and adaptive power dissipation,” IEEE J. Solid-State Circuits,
vol. 42, no. 5, pp. 1090–1099, May 2007.
[6] Y. Palaskas and Y. Tsividis, “Power-area-DR-frequency-selectivity
tradeoffs in weakly nonlinear active filters,” in Proc. International
Symposium on Circuits and Systems ISCAS ’03, vol. 1, 25–28 May 2003,
pp. I–453–I–456.
[7] A. Yoshizawa and Y. Tsividis, “A channel-select filter with agile blocker
detection and adaptive power dissipation,” IEEE J. Solid-State Circuits,
vol. 42, no. 5, pp. 1090–1099, May 2007.
[8] Y. Palaskas and Y. Tsividis, “Power-area-DR-frequency-selectivity
tradeoffs in weakly nonlinear active filters,” in Proc. International
Symposium on Circuits and Systems ISCAS ’03, vol. 1, 25–28 May 2003,
pp. I–453–I–456.
[9] H. Khatri, L. Liu, T. Chang, P. S. Gudem, and L. E. Larson, “A SAW-less
CDMA receiver front-end with single-ended LNA and single-balanced
mixer with 25% duty-cycle LO in 65nm CMOS,” in Proc. IEEE Radio
Frequency Integrated Circuits Symposium RFIC 2009, 7–9 June 2009,
pp. 13–16. [10] J. Mitola III, “Cognitive radio for flexible mobile multimedia
communications," in Proc. IEEE International Workshop on Mobile
Multimedia Communications, 15-17 Nov. 1999, pp. 3-10.
[11] IEEE 802.22 Working Group, http://www.ieee802.org/ 22/.
[12] FCC, “In the matter of unlicensed operation in the TV broadcast bands:
second report and order and memorandum opinion and order,” Tech. Rep.
08-260, Nov. 14 2008.
[13] S. Haykin, “Cognitive radio: brain-empowered wireless communications,”
IEEE J. Sel. Areas Commun., vol. 23, no. 2, pp. 201–220, Feb
2005.
[14] E. Au, G. Chouinard, and Z. Lei, "IEEE P802.22 wireless RANs receiver
performance evaluation criteria," IEEE 802.22-08/0326r2,
http://www.ieee802. org/22/, Dec. 2008.