Narda Microwave has introduced its Model 10512 Programmable Signal Source that digitally creates frequency-modulated noise waveforms and applies them to a carrier whose center frequency can be varied ±50 MHz in less than 100 nanoseconds. With such characteristics this linearized Voltage Controlled Oscillator (VCO) is well suited for use as a fast-hopping signal generator, programmable noise source or arbitrary signal generator.

Characteristics of the waveforms generated by the Model 10512, such as video bandwidth, dispersion bandwidth — to 400 MHz — and power level, can be programmed by the user, or remotely by a host system. The waveforms include ramp, sinusoidal, triangle, square wave, and random, among others. The standard model operates up to 3 GHz but much higher frequency ranges are available. The signal source consumes 11 W, measures 4 in. x 4 in. x 0.6 in. and weighs less than 1 oz. — yet it is rugged enough to meet military specifications for shock and vibration.

The Model 10512 actually employs two VCOs and a high-speed, PIN-diode-based single-pole, double-throw switch that enables it to change from one frequency to another at extremely high speed. One VCO can operate at one frequency while the other is "staged" to operate at a higher frequency. By "ping-ponging" the two VCOs, it is possible to hop between frequencies much faster than by retuning a single VCO. While the tuning time for a single VCO is less than 100 ns, switching time between two retuned VCOs via the high-speed switch is less than 15 ns.

For adjusting signal amplitude, each channel utilizes a digitally-controlled attenuator (DCA) with a 63-dB range that is controllable in 1-dB steps. The DCA settles between any two states in less than 100 ns. The Model 10512 delivers +16-dBm RF output power with a 1-dB gain compression point of +21 dBm. The module exercises real-time control over all signal parameters, maintaining them within tight tolerances over a broad range of operating conditions.

The standard Model 10512 has a frequency range of 2.8 to 3.2 GHz, but other frequencies can be accommodated, well into the millimeter-wave region.

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