FUNCTIONAL

FREQUENCY

DESCRIPTION

SYNTHESIS

 

signal that (depending on polarity) causes the VCO

 

frequency to increase or decrease to reduce any

 

phase difference. When the two inputs match, the

 

loop is said to be locked. The variable input from the

 

VCO then equals the reference input in phase, fre-

 

quency, accuracy, and stability.

 

In practical applications a frequency divider is

 

placed between the output of the variable oscillator

 

and the variable input to the phase-lock loop. The

 

circuit can then be used to control a frequency that

 

is an exact multiple of the reference frequency. In

 

this way, the variable oscillator acquires the stabil-

 

ity of the reference without equaling its frequency.

 

In the A3 Reference Loop, the 100 MHz oven-

 

controlled crystal oscillator (OCXO) can be con-

 

trolled by the phase-lock loop using a 10 MHz refer-

 

ence. This is because a divide-by-ten circuit is

 

between the OCXO’s output and the variable input

 

to the phase-lock loop. Both inputs to the phase de-

 

tector will be 10 MHz when the loop is locked.

 

If a programmable frequency divider is used, a

 

number of frequencies can be phase-locked to the

 

same reference. The limitation is that all must be

 

exact multiples of the reference. The A4 Coarse

 

Loop and A5 Fine Loop both use programmable fre-

 

quency dividers.

Overall

The YIG-tuned oscillator generates a high-power RF

Operation

output signal that has low broadband noise and low

 

spurious content. The frequency of the YIG-tuned

 

oscillator is controlled by means of (1) its main tun-

 

ing coil and (2) its FM (fine tuning) coil. Main tun-

 

ing coil current from the YIG Driver PCB coarsely

 

tunes the YIG-tuned oscillator to within a few

 

megahertz of the final output frequency. The YIG

 

phase-lock loop is then used to fine tune the YIG-

 

tuned oscillator to the exact output frequency and to

 

reduce FM noise close to the carrier.

 

One input to the YIG Loop is the 219.5 to 245 MHz

 

signal from the Coarse Loop. This signal is ampli-

 

fied to drive the step-recovery diode. The step-

 

recovery diode produces harmonics of the coarse

 

loop signal (￿1.9755 to >20 GHz). These harmonics

 

are used by the sampler.

 

The other input to the sampler is the RF output sig-

 

nal from the YIG-tuned oscillator. Mixing this RF

2-10

682XXB/683XXB MM

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Anritsu 682XXB, 683XXB manual Overall
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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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