YIG-Tuned Bipolar Oscillators Cover 2 to 18 GHz

To provide enhanced performance with low frequency-modulation (FM) noise, a series of yttrium-iron-garnet (YIG) oscillators rely on thin-film technology and low-noise bipolar transistors. In addition, the oscillators were designed using computer-aided-design (CAD) techniques. Both the 10- and 30-mW versions are electronically tunable over the entire fundamental-frequency 2-to-18-GHz frequency range. Thanks to a proprietary magnetic circuit and the coupling technique used between the YIG sphere and active element, the linearity of these oscillators is better than +/-12.5 MHz. From 4.0 to 18.0 GHz, for example, the YOM3679 delivers at least 13 mW RF output power with power variation of 3 dB. With a VSWR of 1.50:1, the pulling figure is 0.5. FM noise is -115 dBc offset 100 kHz from the carrier and -90 dBc offset 10 kHz from the carrier. A typical analog driver control input of 0 to 10 V tunes the oscillator over the full frequency band. P&A: Available now.