2026 Marconi RF Generator Used

The 2026 is a multiple source generator which offers two RF signal generators in one box with a third source available as an option. Each source is a fully functional RF signal generator with AM, FM, ΦM, 2FSK, 4FSK and pulse modulation capability.

The 2026 is ideal for use in R&D and manufacturing where there is a need for two or three combined sources for conducting tests such as intermodulation and selectivity performance of components and receiver assemblies.

To aid the user to undertake difficult test procedures simply and without ambiguity, the 2026 provides application-specific modes of operation. Application modes include amplifier two and three-tone intermodulation, receiver intermodulation and receiver selectivity. A rotary control and up/down keys allow easy modification of the selected parameters.

Measurement Accuracy

The use of a built-in combiner, switches and cables eliminates many of the measurement uncertainties introduced by connecting together separate signal generators. The 2026 thereby guarantees the level of intermodulation products introduced during amplifier or receiver intermodulation testing.

All alignment processes, including the internal frequency standard and the correction factors for the signal source RF paths, are digitally derived so realignment can be undertaken without removal of external covers. Digital adjustment also eliminates the use of mechanical adjusters, minimizing long term drift and vulnerability to mechanical shock.

Application Modes

The 2026 has a Set Up Key to enable the applications to be selected. Each Set Up is displayed as a pictorial representation of the internal signal source routing. A spectral diagram is used to show the parameters to be entered in each application in well known engineering terminology.

For example, selecting ‘Intermodulation on a Receiver Test’ allows the signal sources to be automatically set by entering the receiver input frequency and level, the ratio of the level of the two interferers (relative to the receiver input level) and the offset frequency (channel spacing).

Other application modes include 2 and 3 tone intermodulation tests on amplifiers, and receiver selectivity.

Flexible Source Routing 

Each of the signal sources can either be routed to a separate output connector or switched to the input of an RF combiner network before being fed to the combiner output connector. The combiner routing is set up quickly and effectively using the Combiner Set Up menu. The flexibility of the signal routing allows the 2026 to accept an external signal generator, such as the 2050 Digital and Vector Generator, to substitute for one of the internal sources, to enable different forms of carrier signals to be produced.

Automatic Source Coupling

As an alternative to the application modes, the 2026 MultiSource Generator allows the frequency and level of the internal RF sources to be coupled together with a user defined offset. The source frequencies can have an offset with an additional harmonic (or sub-harmonic) relationship to simplify the testing of harmonic converters and divider systems. The coupling factors are entered by an easily understood format using a dedicated coupling menu. The ability to set sources to track each other greatly simplifies the testing of mixers, multipliers and dividers by reducing the number of active controls required.

Sweep

The 2026 allows one of the RF sources to be frequency swept with user defined start, stop, and step values to reduce the amount of operator time or GPIB overhead. By enabling the coupling facility, sweeping one source will simultaneously sweep the other internal RF sources to allow automated swept measurements on frequency conversion devices to be made. The sweep can be performed with modulation enabled for swept measurements of receiver immunity characteristics.

High RF Output

The high RF level of the individual outputs is ideal for testing components and ensures that the 2026 can generate high RF levels at the combiner output while maintaining low levels of intermodulation.

Comprehensive Modulation

Each signal source is capable of being independently modulated from its own fully programmable modulation source to ensure maximum flexibility. The internal modulation sources are each capable of generating sine, triangle or square wave signals. Amplitude, frequency and phase modulated carriers can be generated from the internal modulation sources or from the independent external inputs. The frequency modulation system provides excellent performance in the DC coupled mode with very low carrier frequency error and stability ensuring that the generator can accurately test receiver's sensitive to small frequency errors.

Pulse Modulation

Each source is capable of being independently pulse modulated to allow the simulation of TDD or TDMA RF signal bursts with pulse on/off ratios of better than 40 dB and a rise time of less than 10 μs.

FSK

In addition to the analog FM facilities, the 2026 MultiSource Generator supports 2 and 4-level FSK signals from external logic inputs. The FM deviation generated is set by keyboard entry of the required deviation. The facility is ideal for testing paging receivers and RF modems.

High Spectral Purity

Measurement of receiver selectivity and ultimate signal-to-noise ratio requires good spectral purity. The 2026 has a low residual FM of typically 3 Hz and typical sideband noise of -121 dBc/Hz at 20 kHz offset from 1 GHz, to allow demanding measurements to be made.

Programming

A GPIB interface is fitted so that all standard signal generator functions are controllable over the bus. The protocol and syntax of GPIB commands has been designed in accordance with IEEE 488.2 standard to facilitate the generation of ATE programs.

Low Cost of Ownership

An electronic trip protects the individual source outputs against the accidental application of reverse power. Careful attention to the thermal design and the use of well-proven signal generator modules gives high reliability and calibration validity.

The use of flash memory and software download via the RS-232 interface means the 2026 can be upgraded with its covers fitted.