FUNCTIONAL

ALC/AM/PULSE

DESCRIPTION

MODULATION

Power Sweep

In this mode, the CPU has the ALC step the RF out- put through a range of levels specified by the user. This feature can be used in conjunction with the sweep mode to produce a set of identical frequency sweeps, each with a different RF power output level.

Amplitude Modulation

Amplitude modulation (AM) of the RF output signal is accomplished by summing an external or internal modulating signal into the ALC loop. External modulating signals come from the front panel or rear panel AM IN inputs; the internal modulating signal comes from the A8 Function Generator PCB. The AM Input Sensitivity DAC and the AM Calibra- tion DAC, under the control of the CPU, adjust the modulating signal for the proper amount of AM in both the linear (log amp in) and the log (log amp by- passed) modes of operation. The adjusted modulat- ing signal is summed with the level reference, slope, and detector inputs into the ALC loop. This pro- duces an ALC control signal that varies with the modulating signal. The action of the ALC loop then causes the envelope of the RF output signal to track the modulation signal.

 

Pulse Modulation Operation

 

During pulse modulation, the ALC level amplifier

 

(A10 ALC PCB) is operated as a sample/hold ampli-

 

fier. The level amplifier is synchronized with the

 

modulating pulses from the A6 Pulse Generator

 

PCB so that the ALC loop effectively operates only

 

during the ON portion of the pulsed modulated RF

 

output.

Pulse

The A6 Pulse Generator PCB provides the internal

Generator

pulse generating function for the 682XXB/683XXB.

Operation

It also interfaces external pulse inputs from the

 

front or rear panel connectors to the pulse modula-

 

tor driver in the external mode.

 

The pulse generator produces a pulse modulation

 

waveform consisting of single, doublet, triplet, or

 

quadruplet pulse trains at variable pulse rates,

 

widths, and delays. It operates at two selectable

 

clock rates—10 MHz and 40 MHz. In addition, the

 

pulse generator produces a sync pulse and video

 

pulse output that goes to the rear panel and a sam-

 

ple/hold signal that goes to the A10 ALC PCB. The

 

sync pulse output is for synchronizing auxiliary in-

2-18

682XXB/683XXB MM

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Anritsu 682XXB, 683XXB manual Power Sweep, Amplitude Modulation, Pulse Modulation Operation
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682XXB, 683XXB specifications

The Anritsu 683XXB and 682XXB series are advanced vector network analyzers (VNAs) renowned for their precision and versatility in characterizing RF and microwave components. Designed for engineers and technicians involved in the development, manufacturing, and testing of high-frequency devices, these analyzers offer state-of-the-art technology that ensures optimal performance in various applications.

One of the hallmark features of the Anritsu 683XXB and 682XXB is their high dynamic range, which allows for accurate measurements of small reflection and transmission coefficients, essential for assessing the performance of complex RF structures. With frequency coverage extending from DC to 70 GHz, these analyzers cater to a broad spectrum of applications, making them suitable for industries such as telecommunications, aerospace, and automotive.

The user-friendly interface of the Anritsu VNAs is complemented by a high-resolution display, which facilitates easy navigation through measurement setups and results. The analyzers feature multiple measurement modes, including S-parameter measurements, time-domain analysis, and noise figure measurements, providing engineers with comprehensive tools for device characterization.

Both the 683XXB and 682XXB implement advanced calibration techniques, including automated calibration and error correction methods, to enhance measurement accuracy. These methods significantly reduce the uncertainties associated with test setups, enabling reliable performance evaluations of components like filters, amplifiers, and antennas.

Anritsu’s proprietary technologies, such as the VectorStar and ShockLine series integration, further empower the 683XXB and 682XXB models. These technologies enable high-throughput testing and improved measurement stability, addressing the needs of modern production environments that demand rapid turnaround times without sacrificing precision.

Additionally, the analyzers come equipped with various connectivity options, including USB, LAN, and GPIB, ensuring seamless integration into automated test systems. This adaptability enhances the analyzers' utility in both laboratory settings and field operations.

In conclusion, the Anritsu 683XXB and 682XXB series vector network analyzers represent the pinnacle of RF and microwave testing technology. With their unmatched precision, comprehensive measurement capabilities, and advanced calibration techniques, these instruments are indispensable tools for professionals striving to push the boundaries of high-frequency device performance and reliability.
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