A Compact, Low Cost, Low Power YIG Synthesiser for Long Haul Applications

YIG oscillators are very attractive because of their low noise and wide tuning bandwidth, but they are susceptible to microphonics and to electromagnetic fields. Alcatel Italia designed a synthesiser with a new SMT YIG oscillator produced by SiversIMA, unique of its kind. This allows to design and assemble compact synthesisers without connection wires for the output, power supply and tuning control from oscillator to PLL circuitry. No mechanical devices for vibration and magnetic immunity are required because shock absorbers and a very effective ¿-metal magnetic shield are included in the oscillator itself. Therefore the design is based on a narrow bandwidth single-loop topology rather than an expensive, complex power consuming double-loop. This synthesiser is conceived only for the use in Indoor Unit Long Haul Radio Link systems, where temperature fluctuations and vibrations are limited.