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Implementation of Tunable Gm-C High-pass Filter using Linearized Transconductor

Affiliations

  • School of Electronics Engineering, VIT University, Vellore - 632014, Tamil Nadu, India

Abstract


Objective: Now a day there is an increase demand for higher linear circuits in a wireless communication system. The linear circuit provides better support for wireless communication. To process the signals and remove unwanted block or interferers, the transmitting end and receiving end must consist of highly linearity circuit. Methods/Statistical Analysis: A tunable Gm-C high-pass filter implemented using linearized transconductor circuitry, is proposed in this paper. By employing a dual path feed forward technique, the transconductor circuitry cancels the term Gm3 thus acting a good linear Voltage-to-Current conversion. This design consists of a voltage buffer which uses only inverters, which can drive transconductor with differential inputs. A higher order admittance method is utilized to synthesize the filter. The high pass filter is implemented in 180nm UMC CMOS technology. Findings: A linearization transconductor circuit system is proposed. Using voltage buffer which incorporates inverters and copied unique transconductors, better linearization is achieved. A wider tuning range of the filter cutoff frequency varying from 0.17 MHz to 0.85 MHz is obtained. A low current consumption of 10 mA to 30 mA over the tuning range is observed. Further, the harmonic distortion analysis revealed that the input-referred third-order intercept point (IIP3) is +25.84 dBm with a 1-dB compression point being +9.35 dBm. A filter linearity of less than one percent (<1%) shows that the proposed design has better linearity. Application/Improvements: The simulation results validates that the filter design is highly linear, thus an efficient line arization technique is proposed. Further, this design methodology can be adapted for transconductors having varied differential inputs, and also provides design feasibility for multiple processes.

Keywords

Gm-C Filter, High Pass Filter, Linearization Technique, Transconductance.

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References


  • Razavi B. RF Microelectronics. 2nd ed., NJ: Pearson; 2012.
  • Aparin V, Larson LE. Modified derivative superposition method for linearizing FET low-noise amplifiers. IEEE Transactions on Microwave Theory and Techniques. 2005 Feb; 53(2):571–81.
  • Kwon K, Lee K. A 23.4 mW 68 dB dynamic range low band CMOS hybrid tracking filter for ATSC digital TV tuner adopting RC and Gm-C topology. IEEE Transactions on Circuits and Systems I: Regular Papers. 2011 Oct; 58(10):2346–54.
  • Ding Y, Harjani R. A +18 dBm IIP3 LNA in 0.35 μm CMOS. IEEE International Solid-State Circuits Conference; 2001 Feb. p. 162–3.
  • Mobarak M, Onabajo M, Silva-Martinez J, Sanchez-Sinencio E. Attenuation-predistortion linearization of CMOS OTAs with digital correction of process variations in OTA-C filter applications. IEEE Journal of Solid-State Circuits. 2010 Feb; 45(2):351–67.
  • De Matteis M, D'Amico S, Baschirotto A. A 0.55 V 60 dB-DR fourth-order analog baseband filter. IEEE Journal of Solid-State Circuits. 2009 Sep; 44(9):2525–34.
  • Khorramabadi H, Gray PR. High-frequency CMOS continuous-time filters. IEEE Journal of Solid-State Circuits. 1984 Dec; 19(6):939–48.
  • Ru Z, Klumperink EAM, Saavedra CE, Nauta B. A 300–800 MHz tunable filter and linearized LNA applied in a low-noise harmonic-rejection RF-sampling receiver. IEEE Journal of Solid-State Circuits. 2010 May 2010; 45(5):967–78.
  • Sunitha, Amrithapriyam. Mobile user position system for indoor technologies using application of RADAR. Indian Journal of Science and Technology. 2016 Aug; 9(32):1–6.
  • Lim Y, Nam S. Target-to-clutter ratio enhancement of images in through-the-wall radar using a radiation pattern-based delayed-sum algorithm. Journal of Electromagnetic Engineering and Science. 2014 Dec; 14(4):405–10.
  • Devapal D, Kumar SS, Christy Jojy. Comprehensive Survey on SAR image Despeckling Technique, Indian Journal of Science and Technology. 2015 Sep; 8(24):1–5.
  • Olsak M, Matejicek L, Vrba K, Smekal Z. Realization of Nth-order electronically tunable highpass filter employing only N OTAs. 10th International Conference on Telecommunications, 2003 Feb 23 – Mar 1; 2003. p. 671–6.

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