High-resolution frequency synthesizers over X-band using SILPLL opto-electronic oscillators

Optoelectronic oscillators with their demonstrated low phase noise are popular due to the increasing demand of very clean local oscillator and clock signal sources. Forced techniques are applied on an OEO system reducing the phase noise and suppresses side mode observed in standard OEO with long delays. A frequency synthesizer working at X-band is demonstrated using dispersive optical transversal filter cascaded with YIG filter to electronically fine and coarse tune the oscillation frequency of the synthesized frequency, as a replacement for fixed frequency high Q metallic filter. Close-in to carrier phase noise of -135 dBc/Hz at 10 kHz are reported by V
_π/2
operation of a Mach-Zehnder (MZM) over 9 GHz to 11 GHz with frequency tuning step as small as 10 kHz/pm.