Figure 1 CNT-104R frequency calibrator/analyzer.
Pendulum’s new CNT-104R is the latest addition to its high performance, multichannel frequency and time-interval calibration analyzer family. This compact benchtop unit combines an ultra-stable 10 MHz Rubidium frequency reference with a four-channel advanced frequency analyzer, allowing users to verify and calibrate up to four oscillators/clocks in parallel on four input channels simultaneously. The unit is shown in Figure 1.
The unit can also be equipped with an optional multiband GNSS receiver that disciplines the built-in Rubidium clock. This eliminates any small intrinsic drift due to aging and provides exceptional accuracy for both portable and laboratory test applications. The GNSS control not only enables continuous disciplining of the Rubidium time base, but it allows the user to reset any accumulated aging when operated in previously GNSS-denied environments.
The GNSS receiver provides an uncertainty of 10 ns rms to UTC. This enables the calibration of one to three external sync signals with unprecedented accuracy. The internal phase/time reference functionality allows users to view drift over time and frequency distribution, including traditional numeric and statistical parameters, on the large color graphic display.
Featuring a time resolution of less than 7 ps, 12 to 13 digits/sec frequency resolution and variable gate time setting from 50 nsec to 1000 sec, the analyzer is purpose-built and optimized for demanding metrology applications. All four input channels support gap-free, zero-deadtime counting, providing back-to-back measurements without losing any cycle, even over extended measurement periods. The standard frequency range for each channel is up to 400 MHz. However, input channel C can support microwave frequencies up to 24 GHz via different software upgrade options.
The CNT-104R is also a high performance modulation domain analyzer for the advanced user. The analyzer has a high speed design and sample rates of up to 20 million measurements per second for four parallel input signals. This allows very fast frequency variations or phase/time changes to be captured in real-time.
The unit is offered in its standard configuration with one 10 MHz reference output with frequency stability of 1 × 10-12 over a 24-hour average when the optional integrated GNSS receiver controls the Rubidium oscillator. Additional, highly stable 10 MHz outputs are achieved when the unit is used in conjunction with Pendulum’s FDA-301A frequency distribution amplifier. This amplifier multiplies the number of outputs by a factor of 4, 8 or 12 over copper or 6, 12, or 18 via fiber interfaces, depending on the output module configuration.
The four-channel CNT-104R design enables four parallel frequency measurements. This means that the CNT-104R can replace four frequency counters in a test system, decreasing the effective cost per counter. It can also provide an ultra-stable 10 MHz reference frequency to the test stand. This makes the CNT-104R the equivalent of five separate instruments in a single box, reducing space requirements and capital investment. You can choose between Ethernet or WLAN as a communication interface to a variety of devices, including PCs, laptops, tablets or the test system controller. The bus speed, with block measurements occurring at up to 170k measurements per second, reduces test time in ATE test systems compared to existing solutions.
A large, color touch screen, along with an intuitive menu structure, allows simple navigation and setup of instrument test parameters. The unit is equipped standard with a Gbit Ethernet interface, offering complete flexibility for remote control and test result data transfer. Users can also operate the unit using a wireless mouse and a connected USB dongle. A built-in web server allows the unit to be accessed and controlled from your lab bench or almost anywhere in the world via a PC or mobile device using the integrated web interface. This enables wired Gigabit Ethernet or wireless Wi-Fi connectivity to provide flexible remote control capability.
Figure 2 Four simultaneous signals on CNT-104R display.
Notable features of the CNT-104R are the menu-oriented settings in the graphic display. Intelligent AUTO SET configures the best settings for each measurement. Thanks to the guided instruction on most setting pages, the non-expert can easily make correct settings. Valuable signal information, given in multiparameter displays, removes the need for other instruments like DVMs and scopes for quick signal verification. Measured results are presented in numerical and graphical formats. Graphical presentation of results like distribution, trends etc., gives a better understanding of the nature of jitter. It also provides a much better view of changes versus time (e.g., drift). A toggle function allows test data to be viewed in numerical, statistical, distribution and timeline modes. It is quite easy to capture and toggle between views of the same data set. Figure 2 shows a typical display of four simultaneous signals. This display makes it easy to see why the CNT-104R can be considered as four instruments in one.
Pendulum’s frequency counters/analyzers are reputable and well-known as industry-leading time and frequency measurement instruments. For over 60 years, Pendulum Instruments has served the aerospace and defense, telecom, metrology and R&D industries worldwide. Contact us to learn how the CNT-104R can be configured according to your specific needs and/or budget demands.
Pendulum Instruments Inc.
Redwood City, Calif.
www.pendulum-instruments.com
