Cognitive and encrypted communications: state of the art and a new approach for frequency-agile filters

Several communication techniques are investigated in the first part of this paper: software radio, cognitive radio and encrypted communications. State of the art of research on agile and reconfigurable filters, passive as well as active, necessary for transceivers is then made and various tables for comparison are given. In the third part, a new theory for a 2nd-order frequency-agile filter is introduced. The center frequency of the filter is proportional to the gain of a feedback amplifier and thus can be tuned over a wide frequency range. This new theory is thereafter generalized to the nth-class leading to a center frequency proportional to (A)n/2. Simulation results of band pass agile filters in current mode and made from second-generation current controlled conveyors (CCCII+) in 0.25 m m SiGe BiCMOS technology are given for n = 1 and n = 2. These simulation results along with results of measurements carried out on the fabricated filters entirely confirm the new approach. They also highlight the improvements to be expected for cognitive and encrypted communications.

Cognitive and encrypted communications: state of the art and a new approach for frequency-agile filters

Several communication techniques are investigated in the first part of this paper: software radio, cognitive radio and encrypted communications. State of the art of research on agile and reconfigurable filters, passive as well as active, necessary for transceivers is then made and various tables for comparison are given. In the third part, a new theory for a 2nd-order frequency-agile filter is introduced. The center frequency of the filter is proportional to the gain of a feedback amplifier and thus can be tuned over a wide frequency range. This new theory is thereafter generalized to the nth-class leading to a center frequency proportional to (A)n/2. Simulation results of band pass agile filters in current mode and made from second-generation current controlled conveyors (CCCII+) in 0.25 m m SiGe BiCMOS technology are given for n = 1 and n = 2. These simulation results along with results of measurements carried out on the fabricated filters entirely confirm the new approach. They also highlight the improvements to be expected for cognitive and encrypted communications.

___

  • M., “Overview: Trends and Implementation Challenges for Multi- Band/Wideband Communication,” Rensselaer Polytechnic Institute, April 2007,
  • http://www.ecse.rpi.edu/Homepages/shivkuma/teaching/sp2007/wbn2007/wbn2007-hella-talk.ppt.
  • http://en.wikipedia.org/wiki/Advanced Encryption Standard.
  • http://en.wikipedia.org/wiki/RSA
  • Andren, C., “A Comparison of Frequency Hopping and Direct Sequence Spread Spectrum Modulation for IEEE 802.11 Applications at 2.4 GHz,” 1997, http://www.intersil.com/design/prism/papers/ds-v-fh.pdf.
  • http://www.reachinformation.com/deŞne/Frequency-hopping spread spectrum.aspx.
  • Robert K. Acherman “Software Enables Radio Family Ties,” Signal Magazine September 2002, p. 31.
  • Koochakzadeh, M., Tamijani, A., “Multi-scale tunable Şlter covering a frequency range of 6.5:1,” Microwave Symposium Digest, 2008 IEEE MTT-S International, 15–20 June 2008, pp. 1023–1026.
  • J. Brank, Z. J. Yao, M. Eberly, A. Malczewski, K. Varian, and C. L. Goldsmith, “RF MEMS-Based Tunable Filters,” Int. J. of RF and Microwave CAE, vol. 11, no. 5, Sept. 2001, pp. 276–284.
  • Arnaud Pothier, “Conception, Realisation Et Test De Microcommutateurs Micro-Electromecaniques Et Application Aux Circuits Hyperfrequences ReconŞgurables,” Doctoral Thesis, Xlim Lab., Limoges, France, December 2003.
  • Ramachandran, D. Oz, A. Saraf, V.K. Fedder, G.K. Mukherjee, T., “MEMS-enabled reconŞgurable VCO and RF Şlter,” IEEE RFIC Symposium, 6–8 June 2004, pp. 251–254.
  • El Hassan, M., Kerherve, E., Deval, Y., Belot, D., “A New Method to ReconŞgure BAW-SMR Filters Using CMOS Transistors,” IEEE/MTT-S International Microwave Symposium, 3–8 June 2007, pp. 1603–1606.
  • Alexandre Augusto Shirakawa, “´Etude, Synth`ese Et R´ealisations De Filtres Baw Pour Applications Mobiles,” Doctoral Thesis, IMS Lab., Bordeaux, France, November 2006.
  • RazaŞmandimby S., Tilhac C., Cathelin A., Kaiser A., Belot D., “A novel architecture of a tunable bandpass BAW- Şlter for a WCDMA transceiver,” Analog Integrated Circuits and Signal Processing, Vol. 49, Issue 3, December 2006, pp. 237–247.
  • Al-Ahmad, M., Matz, R., Russer, P., “0.8 GHz to 2.4 GHz Tunable Ceramic Microwave Bandpass Filters,” IEEE MTT-S, 2007, pp. 1615–1618.
  • Kim, Hyun-Suk; Hyun, Tae-Seon; Kim, Ho-Gi; Kim, Il-Doo; Yun, Tae-Soon; Lee, Jong-Chu, “Orientation effect on microwave dielectric properties of Si-integrated Ba0.6Sr0.4TiO3thin Şlms for frequency agile devices,” Applied Physics Letters, No. 89, 2006.
  • Nosrati, M., Atlasbaf, Z., “A New Miniaturized Electronically Tunable Bandpass Filter, Antennas,” 7th Interna- tional Symposium on Propagation & EM Theory, ISAPE APOS’06, 26–29 October 2006, pp. 1–5.
  • Karim, MF., Ai-Qun Liu, Alphones, A., Aibin Yu, “A ReconŞgurable Micromachined Switching Filter Using Periodic Structures,” IEEE Transactions on Microwave Theory and Techniques, Vol. 55, Issue 6, June 2007, pp. 1154–1162.
  • Nath, J., Fathelbab, W., Franzon, P.D., Kingon, A.I., Ghosh, D., Maria, J.-P., Steer, M.B., “A tunable combline bandpass Şlter using barium strontium titanate interdigital varactors on an alumina substrate,” IEEE MTT-S International Microwave Symposium, 2005, 12–17 June 2005, pp. 595–598.
  • Carey-Smith, BE., Warr, PA., Beach, MA., “MEMS-driven flexible Şlters for cognitive radio,” IST Mobile and Wireless Communications Summit, Dresden, Germany, June 2005, http://rose.bris.ac.uk/dspace/handle/1983/874.
  • D¨ulger, F., S´anchez-Sinencio, E., Silva-Martinez, J., “A 1.3 V 5 mW fully integrated tunable bandpass Şlter at 2.1 GHz in 0.35- μ m CMOS,” IEEE journal of Solid-State Circuits, vol. 38, No 6, 2003, pp. 918–928.
  • Pipilos, S., Tsividis, Y.P., Fenk, J., Papananos, Y., “A Si 1.8 GHz RLC Şlter with tunable center frequency and quality Factor,” IEEE journal of Solid-State Circuits, vol. 31, No 10, 1996, pp. 1517-1525.
  • Biolek, D., Biolkova, V., Kolka, Z., “Universal Current-Mode OTA-C KHN Biquad,” International journal of Electronics, Circuits and Systems Vol. 1, No 4, pp. 214–217.
  • Biolek, D., Biolkova, V., Kolka, Z. “Universal current-mode Gm-C biquad,” 18th International Conference Ra- dioelektronika, Prague, Czech Republic, 24–25 April 2008, pp. 1–3.
  • Lin, P.M., “Signal Flow Graph In Filter Analysis And Synthesis,” Circuits and Filters Handbook, Chap. 18, IEEE Press 1995, pp. 619–638.
  • Ngamkham, W. Pawarangkoon, P. Kiranon, W “A novel noninteracting Electronically Tunable Universal Filter,” International Symposium on Communications and Information Technologies, ISCIT ’06. Oct. 2006, pp. 843–846.
  • Chunhua Wang , Haiguang Liu, Yan Zhao, “A New Current-Mode Current-Controlled Universal Filter Based on CCCII(±),” Circuits, Systems, and Signal Processing, Birkh¨auser Boston, Vol. 27, No. 5, October 2008, pp. 673– 682.
  • El Oualkadi, A.E., El Kaamouchi, M., Paillot, J.-M., Vanhoenacker-Janvier, D., Flandre, D., “Fully Integrated High-Q Switched Capacitor Bandpass Filter with Center Frequency and Bandwidth Tuning,” IEEE Radio Frequency Integrated Circuits (RFIC) Symposium, 3–5 June 2007, pp. 681–684.
  • Cheung, Vincent S.L., Luong, Howard Cam H., “Design of Low-Voltage CMOS Switched-Opamp Switched- Capacitor Systems,” The Springer International Series in Engineering and Computer Science, Vol. 737, 2003, ISBN: 978-1-4020-7466-0.
  • Seng-Pan U, Rui Paulo Martins, Jos´e Epifˆanio da Franca. “Design of Very High-frequency Multirate Switched- capacitor Circuits: 0387261214, 9780387261218.
  • Mariano A., Goumballa B., Dallet D., Deval Y., Begueret, J-B., “Design of a high-speed CMOS multi-bit quantizer for continuous-time Delta-Sigma Modulator applications,” Analog Integrated Circuits and Signal Processing, vol. 57, No. 1-2, November 2008, pp. 79–87.
  • Yue Wu, Chunlei Shi, Xiaohui Ding, Ismail, M., Olsson, H., “Design of CMOS VHF/RF Biquadratic Filters,” Analog Integrated Circuits and Signal Processing, Vol. 33, Issue 3, December 2002, pp. 239–248.
  • Zhiqiang Gao, Mingyan Yu, Yizheng Ye, Jianguo M “A CMOS bandpass Şlter with wide-tuning range for wireless applications,” Proceedings ISCAS 2006, pp. 867–870.
  • Stornelli, V., Ferri, G., Leuzzi, G., De Marcellis, A., “A Tunable 0.5–1.3 GHz CMOS 2nd order Bandpass Filter with50 Ω Input-output Matching Impedance,” Proceedings ISCAS 2006, pp. 863-866.
  • Multi-Projets website : http://cmp.imag.fr.
  • Fabre, A., Saaid, O., Wiest, F., Boucheron, C., “High frequency applications based on a new current controlled conveyer,” IEEE Transaction on Circuits and Systems, vol. 43, February 1996, pp. 82–91.
  • Fabre, A., Saaid, O., Wiest, F., Boucheron, C., “Low Power Current-Mode Second-Order Bandpass IF Filter,” IEEE Transactions On Circuits And Systems—II: Analog And Digital Signal Processing, Vol. 44, No. 6, June 1997, pp. 436–446.
  • Salem, S., Fakhfakh, M., Masmoudi, D, Loulou, M., Loumeau, P., Masmoudi, N., “A high performances CMOS CCII and high frequency applications,” Analog Integrated Circuits and Signal Processing, Vol. 49, Number 1, October 2006, pp. 71–78.
  • Fabre, A, Saaid, O., Wiest, F., Boucheron, C., “High Frequency High-Q BiCMOS Current-Mode Bandpass Filter and Mobile Communication Application,” IEEE Journal Of Solid-State Circuits, Vol. 33, No. 4, April 1998, pp. 614–625.