The Role of the Activating Structure of Resonators on the Oscillator Phase Noise Correction

Document Type : Original Article

Authors

1 PhD student, Shahid Beheshti Faculty of Electrical Engineering, Tehran, Iran

2 Assistant Professor, Shahid Beheshti Faculty of Electrical Engineering, Tehran, Iran

Abstract

The importance of reducing the oscillator phase noise in most radio equipment, including communication systems, radio sensors and radar, has led to many solutions, one of which is the activation of resonator in the oscillator structure. In this paper, by presentation and analysis of x cases it is shown that the correction of the phase noise by activation of the resonator depends on the model of the resonator and its position in the oscillator and does not happen in all cases. It is also, shown that designing oscillators using extra active feedback loop is not always effective in reducing phase noise. Resonators whose equivalent resistance is in the path of the oscillator loop, do not require an extra active feedback loop in order to obtain the desired phase noise, and the losses are fully compensated by the amplifier which also plays the circuit oscillation role. Two oscillator structures; a series RLC resonator and an RLC resonator with resistor in parallel to capacitor, are compared and the results show that the phase noise is not changed by the extra active feedback loop in the first case but it is decreased by 18 dB in the second one.

Keywords


   [1]      S. B. Cohn, “Microwave Bandpass Filters Containing High-Q Dielectric Resonators,” IEEE Trans. Microw. Theory Techn., vol. 16, no. 4, pp. 218–227, Apr.1968.
   [2]      C. Y. Chang and T. Itoh, “Microwave Active Filters Based on Coupled Negative Resistance Method,” IEEE Trans. Microw. Theory Techn., vol. 38, pp. 1879–1884, Dec. 1990.
   [3]      H. Du, X. Yu, H. Zhang, and P Chen, “A Method to Improve Phase Noise of Oscillator Based on Triangular SIW Resonators,” Microw. Opt. Technol. Lett., vol. 60, no. 5, May. 2018.
   [4]      M. Nick and A. Mortazawi, “Low Phase-Noise Planar Oscillators Based on Low-Noise Active Resonators,” IEEE Trans. Microw. Theory Techn., vol. 58, no. 5, pp.1133-1139, May. 2010.
   [5]      M. Nick, “New Q-Enhanced Planar Resonators for Low Phase-Noise Radio Frequency Oscillators,” Ph.D. dissertation, Dept. Electrical Eng., Michigan Univ., Ann Arbor, MI, 2011.
   [6]      J. Lee, Y. T. Lee, and S. Nam, “High-Q Active Resonator Using Amplifiers and Their Applications to Low Phase-Noise Free-Running and Voltage-Controlled Oscillators,” IEEE Trans. Microw. Theory Technology, vol. 52, no. 11, pp. 2621–2626, 2004.
   [7]      H. Gharib and S. A. Ahmadi, “Voltage Controlled Push-Push Oscillator in the Frequency Range of 1200-1400 Mhz,” Journal of Radar, vol. 6, no. 1, 2018 (Serial No. 19)
   [8]      C. Yang and T. Itoh, “Microwave Active Filters Based on Coupled Negative Resistance Method,” IEEE Tran and microwave theory, vol. 38, no. 12, Dec.1990.
   [9]      Y.-T. Lee, J. Lee, and S. Nam, “High-Q Active Resonators Using Amplifiers and Their Applications to Low         Phase-Noise Free-Running and Voltage-Controlled Oscillators,” IEEE Transactions On Microwave Theory And Techniques, vol. 52, no. 11, Nov. 2004.
[10]      K. Hoffmann and Z. Skvor, “Active Microwave and Millimeter Wave Resonator,” 31st European Microwave Conference, England, 2001.
  • Receive Date: 28 February 2020
  • Revise Date: 09 April 2020
  • Accept Date: 18 April 2020
  • Publish Date: 20 February 2020