Performance Analysis of Micro/Nano Scale Oscillators in GPS Receiver Applications

S.K. Kalyanaraman, J.A. Lovseth, A.J. Reichenauer, J. Rogers

Abstract:	It is widely known that GPS receiver oscillator influences the ability to acquire and track the desired GPS Signal. Depending on the frequency/ phase variations introduced by the GPS receiver’s local reference, this common mode characteristic is tracked out (and not necessarily filtered) by the baseband signal processing and thus has a direct impact on GPS signal recovery. A new generation of Micro/Nano scale resonator based oscillators offer great potential towards redefining the manner in which reference sources have been viewed in GPS receiver designs. Micro/Nanoscale oscillators designed and prototyped under DARPA’s mesodynamics program operate by leveraging non-linearities to optimize phase noise performance at specific frequency offsets in the SSB (Single Side Band) phase noise curve. Live sky GPS signals were successfully acquired and tracked by Rockwell Collins’ GPS receiver which used one of these prototype microscale oscillators [1] as its reference frequency source. These micro/nano scale oscillators currently operate in the 600 MHz region (final design goal is 1 GHz) and are designed to be extremely small (final design goal is 1 cu.mm). They consume very little power and can be ovenized on a limited power budget in order to achieve better frequency stability. These micro/nano scale devices will be shown to have very low acceleration sensitivities which outperform standard AT cut quartz crystal technology. Looking ahead, these micro/nano scale reference sources can potentially be integrated into the GPS chipset resulting in a true all in one GPS solution. However, the close in phase noise performance of these micro scale oscillators needs further improvement in order to meet a host of GPS specific performance requirements. This paper will evaluate the phase noise and Allan deviation performance of micro/nano scale oscillators. Time series and SSB Phase noise data obtained from these devices will be used by baseband GPS signal analysis tools to help determine minimum oscillator requirements (in terms of phase noise/Allan deviation, vibration, shock, frequency stability) for use in GPS receiver solutions. Dominant power law processes in the micro/nano scale oscillators will be identified under different configurations and their impact on the received GPS signal will be discussed. Results of trade off analyses between oscillator performance and GPS signal recovery will be provided. [1] Lovseth, J.A., Hoffmann,T., Kalyanaraman,S.K., Reichenauer,A., Olen,V., Hrncirik, D., “Communication and navigation applications of nonlinear micro/nanoscale resonator oscillators”, Proc. SPIE 8373, Micro- and Nanotechnology Sensors, Systems, and Applications IV, 837305 (May 1, 2012).
Published in:	Proceedings of the 26th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2013) September 16 - 20, 2013 Nashville Convention Center, Nashville, Tennessee Nashville, TN
Pages:	3464 - 3473
Cite this article:	Kalyanaraman, S.K., Lovseth, J.A., Reichenauer, A.J., Rogers, J., "Performance Analysis of Micro/Nano Scale Oscillators in GPS Receiver Applications," Proceedings of the 26th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2013), Nashville, TN, September 2013, pp. 3464-3473.
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