Two other highly integrated source products deserve mention: a line of packaged PLLs with integrated VCOs from Hittite Microwave Corp. and a series of hybrid VCOs based on printed circuit resonators from Synergy Microwave Corp. The former, with integrated fractional-N synthesizers and VCOs in a 6 x 6 mm QFN package, cover 665 MHz to 13.4 GHz. The latter, employing compact coupled planar resonators (CCPRs), measure just 0.3 x 0.3 in. and operate to 12 GHz.

In terms of low phase noise, the opto-electronic oscillator (OEO) developed by OEwaves relies on optical techniques to achieve stable output frequencies even with vibration and changes in temperature. The OEO achieves phase noise of -145 dBc/Hz offset 10 kHz from the carrier for output frequencies from 10 to 12 GHz and a phase noise floor of -174 dBc/Hz. It employs a high-power light source, such as a laser, to drive an optical modulator and a fiber-optic delay line or storage device. The 1550-nm light source is detected at the fiber output and amplified, phase corrected, and filtered before being applied back to the modulator in electrical form.

Spinnaker Microwave developed its model SMS-ACX RF converter/exciter module for electronic warfare (EW) and electronic-countermeasures (ECM) applications. It accepts IF input signals from DC to 1 GHz and upconverts them to low-noise output signals from 10 MHz to 14 GHz (and optionally 40 GHz). It can work with an external IF source, or internal IF signals can be provided by a direct-digital-synthesizer (DDS) source capable of frequency steps as small as 1 Hz. The converter/exciter can switch to any frequency within 50 µs (and optionally to 10 µs).

Using a modular format, the QuickSyn frequency synthesizers from Phase Matrix provide signals from 100 MHz to 10 GHz with resolution as fine as 0.001 Hz and output levels from -25 to +15 dBm. They also switch frequencies in 100 µs or less while maintaining phase noise of -150 dBc/Hz offset 10 kHz from the carrier.

Finally, for those wanting to fabricate their own prototype circuits, the ProtoLaser S system from LPKF Laser & Electronics North America works with ceramic, FR-4, and PTFE laminate materials using a focused laser to etch fine circuit lines and features on a substrate’s conductive metal. The system operates with a high-power laser at 1064 nm with 20 W CW power. The laser can operate in pulsed mode at rates from 10 to 100 kHz. The minimum track width is 50 µm, the minimum gap width is 25 µm, and the minimum corner radius is 12.4 µm. The ProtoLaser S system achieves repeatability of ±2 µm and can produce complex circuits as large as 229 x 305 mm in less than 20 minutes. It is shipped with integrated software that can import a wide range of layout file formats, including Gerber and DXF files.

See associated table