The SMS-B frequency synthesizer from Spinnaker Microwave, Inc. takes advantage of monolithic microwave integrated circuits (MMICs), including VCOs, multipliers, and amplifiers, to cover 2 to 20 GHz (and optionally to 40 GHz) in a unit measuring 3.0 x 3.0 x 0.7 in. Ideal for radar and EW systems, it features better than 500 microseconds switching speed with options to shave that to less than 50 microseconds. The phase noise is -80 dBc/Hz offset 1 kHz from a 10-GHz carrier and -110 dBc/Hz offset 1 MHz from the same carrier. Harmonics are -15 dBc while spurious levels are -60 dBc.

For a trade off in size, the company also offers the SMS-DA direct analog synthesizer in a package measuring 6.5 x 9.5 x 2.3 in. Ideal for SIGINT and EW systems, it tunes from 250 MHz to 4 GHz with better than 300-ns switching speed and 0.1-Hz step size. The phase noise is -95 dBc/Hz offset 1 kHz from the carrier and -100 dBc/Hz offset 10 kHz from the carrier. It provides +10 dBm output power with -20 dBc harmonics and -60 dBc spurious content. Options bring the frequency range to 26 GHz.

Although lacking the bandwidth, but in an even smaller package, the THOR series of broadband frequency synthesizers from EM Research cover 30-percent segments of the 1-to-18-GHz range in a package measuring just 2.5 x 1.1 x 0.4 in. (see figure). With settling time of less than 250 microseconds, these modular synthesizers limit phase noise to -90 dBc/ Hz offset 10 kHz from an 8-GHz carrier and -105 dBc/Hz offset 100 kHz from the same carrier. Harmonics are better than -15 dBc while spurious content is -50 dBc or better at 8 GHz.

With advances in digital technology, designers of DDS sources have dramatically improved the performance of their products for EW applications. For example, ITT Microwave Systems offers rack-mount and modular synthesizers including their WaveCor Dual Synthesizers, with two DDS sources in the same package, one tuning from 300 MHz to 18 GHz, the other from 300 MHz to 2.5 GHz. The technology offers the rare combination of high (1 Hz) frequency resolution with 300-ns switching speed. For the higherfrequency unit, the phase noise is better than –125 dBc/Hz offset 10 kHz from a 9-GHz carrier. For the lower-frequency synthesizer, the phase noise is –140 dBc/ Hz offset 10 kHz from a 1.2-GHz carrier. Spurious levels are better than –65 dBc. As building-block sources for EW systems, Meret Optical also offers DDS sources with clock rates to 1 GHz (outputs to 400 MHz) and exceptional 40 ns switching speed.

When tuning speed is less critical than spectral purity, Micro Lambda Wireless leverages low-noise tunable YIG oscillator technology in its MLSE series of wideband synthesizers, with models covering 2 to 20 GHz and 1 to 22 GHz. Provided in housings measuring just 7 x 5 x 2 in., these high-output (+14 to +20 dBm) synthesizers can tune their full bandwidths and reach a new frequency in about 31 ms. The spurious content is typically –60 dBc.

Although known for its test-equipmenttype frequency synthesizers, such as the 2500B series of microwave signal generators for applications from 100 kHz to 50 GHz, Giga-tronics also supplies modular frequency synthesizers for integration into EW systems. Added to the company’s product lineup through the acquisition of MicroSource, the synthesizers are based on low-noise YIG oscillator technology and offer tuning speeds in the millisecond range from 2 to 24 GHz. Wideband models in the SNY-510 series, for example, provide greater than one octave tuning from 2 to 10 GHz in a modular housing measuring 2.56 x 3.81 x 0.94 in. that is designed to fit into a PXI or VXI chassis. Model SNY-0205-510-01 covers 2.1 to 5.0 GHz in 125-kHz steps with 100-ms typical switching speed. The phase noise is typically -80 dBc/Hz offset 1 kHz from the carrier and -125 dBc/Hz offset 100 kHz from the carrier.

The firm’s SNP 520 series of lownoise synthesizers are offered in bands of 4 GHz or less from 6 to 24 GHz with somewhat lower phase noise. Model SNP-0608-520-01 spans 6 to 8 GHz in 1-Hz steps with +17 dBm output power and 25 ms nominal switching speed. The phase noise is -104 dBc/Hz offset 1 kHz from the carrier and -123 dBc/Hz offset 100 kHz from the carrier. The phase noise drops to -145 dBc/Hz at offsets of 1 MHz and greater from the carrier. Harmonics are held to -25 dBc while spurious levels are -70 dBc or better. The compact module measures 5.00 x 5.50 x 1.60 in. The SNP product line also includes standard models covering 8 to 10 GHz, 10 to 12 GHz, 12 to 16 GHz, 16 to 20 GHz, and 20 to 24 GHz. All models are designed to operate from a single +15-VDC supply.

Phase Matrix offers instrument-type and card-format synthesizers, including its 114XA family of VXI synthesizers. They provide 1-MHz resolution over bandwidths as wide as 10 MHz to 20 GHz and fit into three VXI slots. They feature output levels from +10 to +13 dBm with –30 dBc harmonics, –60 dBc spurious levels, and phase noise of –85 dBc/Hz offset 10 kHz from a 10-GHz carrier.

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