Sweep Generator

sweep generator

[′swēp ‚jen·ə‚rād·ər]
Also known as sweep oscillator.
(electronics)
An electronic circuit that generates a voltage or current, usually recurrent, as a prescribed function of time; the resulting waveform is used as a time base to be applied to the deflection system of an electron-beam device, such as a cathode-ray tube. Also known as time-base generator; timing-axis oscillator.
A test instrument that generates a radio-frequency voltage whose frequency varies back and forth through a given frequency range at a rapid constant rate; used to produce an input signal for circuits or devices whose frequency response is to be observed on an oscilloscope.

Sweep Generator

 

a measuring generator at whose output the frequency of the electric oscillations automatically changes in accordance with a given law. For example, a sinusoidal or sawtooth wave form may be produced. Such generators are usually employed in measuring apparatus used to record the amplitude-frequency and phase-frequency characteristics of components of microwave equipment and to measure such quantities as the standing wave ratio and impedance as functions of frequency. When used in conjunction with an oscilloscope, a sweep generator permits visual observation of the characteristics of the objects being studied.

The components of a sweep generator include a driving oscillator, a frequency modulator, an automatic system for controlling the output voltage or power, and a resonance frequency meter (or a crystal calibrator), which provides frequency marker pips on the screen of the oscilloscope. Sweep generators permit the obtaining of frequency swings in various regions of the electromagnetic spectrum from several megahertz to hundreds of gigahertz. The relative frequency instability during a measurement time of 1–2 min is 10-5-10-4. The sweep width can be as large as an octave. For microwave frequencies, the sweep width is not less than the passband of a standard wave guide. The time required for frequency retuning is 0.02–40 sec; at the lowest frequencies this time can reach several tens of minutes. The output power of a sweep generator is 1–10 milliwatts.

REFERENCES

Valitov, R. A., and V. N. Sretenskii. Radiotekhnicheskie izmereniia. Moscow, 1970.
Kushnir, F. V., V. G. Savenko, and S. M. Vernik. Izmereniia v tekhnike sviazi. Moscow, 1970.
References in periodicals archive ?
The 350S1G6, when used with a sweep generator, will provide a minimum of 350 W of RF power.
After finishing frequency sweep generator continues to generate last frequency until reset is done.
The e-Vap programmable sweep generator allows for sweep frequencies of up to 200 Hz, so that areas not under the beam will have little chance to cool down.
4-GHz software-tunable RF signal and sweep generator includes a built-in RF power detector.
The Model 5S4G11 is a self-contained, air-cooled broadband amplifier that delivers a minimum of 5 W of RF power when used with a sweep generator, while the Model 1S4G11 has similar features, providing a minimum of 1 W of RF power when used with a sweep generator.
The 5S4G11, when used with a sweep generator, will provide a minimum of 5 W of RF power.
Model 500A250A, the first model in the A Series RF amplifier line, covers 10 kHz to 250 MHz, provides a minimum of 500 W of swept power when used with an RF sweep generator, and has an improved noise figure for increased dynamic range.
The 29x Series of one-, two-, or four-channel 100-MS/s 12-b waveform generators defines and simulates signals of 50 MHz or lower for arbitrary waveform, function generator, pulse/pulse train generator, sweep generator, trigger generator, tone generator, and amplitude modulation source applications.
When used as a sweep generator, the amplifier supplies a minimum of 50 W of RF power and the output power can be leveled conveniently to any desired output using the front-panel gain control.
The model 3601 microwave/mm-wave source-locking frequency counter, shown in Figure 2, provides all of the features of the CW series counters and adds a source-locking capability to auto-track and lock unstable frequencies, such as in a sweep generator, to provide an inexpensive ram-wave locked source.
In addition, signal sources have been improved, resulting in the synthesized sweep generator commonly used today.