Abstract
In this paper we present a novel method to measure the free spectral range (FSR) and side-mode suppression ratio (SMSR) of an optoelectronic oscillator (OEO) by adjusting the optical fiber length using an optical path selector and signal source analyzer. We have designed a setup for a single-loop OEO operating around 5 GHz and 10 GHz that features electrical bandpass filters for side-mode suppression. The proposed approach makes it possible to evaluate the FSR and SMSR of OEOs with different optical fiber paths without requiring the changing of fiber spools or optical connectors. This approach could be useful for testbeds that investigate the implementation of an OEO in a 5G radio access network.
Highlights
The optoelectronic oscillator (OEO) [1, 2] is a high-frequency oscillator capable of generating signals in the microwave (300 MHz to 30 GHz) and millimeter wave (30 GHz to 300 GHz) ranges
The main focus of the present paper is on the new approach of the OEO to the free spectral range (FSR) and side-mode suppression ratio (SMSR) measurement; it is worthwhile commenting on the differences in the measured properties of the chemically and lasermanufactured filter in their 3-dB points and central frequency
Evaluation As a result of the measurement in this experimental setup, the FSR is the same for different filters, since the optical fiber length is the same and the bandwidth of the electrical bandpass filter does not impact on the results
Summary
The optoelectronic oscillator (OEO) [1, 2] is a high-frequency oscillator capable of generating signals in the microwave (300 MHz to 30 GHz) and millimeter wave (30 GHz to 300 GHz) ranges. ILGAZ et al./Turk J Elec Eng & Comp Sci a whispering-gallery-mode resonator [3] or a spiral shape optical waveguide [4]. Another benefit of the OEO is that due to the properties of the resonator the level of the phase noise does not change with the frequency of the oscillation signal. The working principle of the OEO can be explained : the optical delay line works as a resonator and the electrical loop is used as a feedback, and if the Barkhausan conditions are satisfied, the OEO begins to oscillate at frequencies determined by the filter’s properties. The filter determines the oscillation frequency when the other conditions (enough gain and correct phase) are met
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
