Keithley enhances RF vector signal analyser line

Keithley Instruments, a provider of advanced electrical test instruments, has upgraded its RF vector signal analyser line with capabilities that reduce signal acquisition and measurement times.

The new Model 2820A RF vector signal analyser, which provides a 40MHz signal acquisition bandwidth with a frequency range of either 400MHz to 4GHz or 400MHz to 6GHz, builds on the capabilities of Keithley's Series 2800 signal analyser line.

It expands the line's applications for testing wireless devices to today's high-throughput, complex-modulation and wide-bandwidth wireless telecom standards.

Three advances allow the Model 2820A to provide a higher testing speed.

First, it can tune to a new frequency in just 250us.

This reduces total transmitter test time when testing a device that operates over a wide frequency band or multiple frequency bands.

Second, a new technique allows the transfer of large amounts of demodulated IQ data from the instrument to a PC for analysis via the USB bus at speeds better than 100Mbit/s, which is said to be 25 times faster than the previous generation of analysers.

The Model 2820A offers two different modes of operation: conventional front-panel control and remote PC control.

A 'desktop control panel' mode makes high-speed transfers possible by letting the PC control the instrument and act as its processor.

This mode bypasses the instrument's internal processor so that data is transferred directly from the DSP-processing blocks to the 100Mbit/s USB bus.

In this mode, the instrument's front-panel display is disabled and the information is shown on the PC's screen.

Users can interact with the PC display and have full control over the instrument, just as if they were operating it through its front panel.

They can capture a Wimax burst, transfer it to a PC and process it by computing nine measurements, including EVM measurements, in as little as 80ms.

Power measurements can be transferred at a speed of less than 700us per measurement.

The Model 2820A also has the ability to post-process continuous blocks of data bursts so that users can capture a series of Edge Evolution bursts without any time gaps, then post-process each burst in series, performing demodulation analysis in less than 10ms per burst.

Third, the Model 2820A employs a single-command, multi-operation technique to minimise transmitter calibration and performance test times.

With a single setup, a range of measurements can be made on transmissions at multiple frequencies, multiple power levels and using multiple standards.

Both power measurements and modulation quality measurements, such as EVM and IQ offset, are included in a single data capture operation.

The company claims that the Model 2820's combination of fast frequency tuning, a desktop control panel, a high-speed USB interface and fast sequence testing makes it the industry's fastest transmitter calibrator and substantially reduces production test time and test costs.

This enhanced speed does not compromise measurement performance, according to Keithley.

A new synthesiser design allows the Model 2820A to provide good low-phase noise performance.

For example, the phase noise is less than 140dBc/Hz at a 300kHz offset on a 2GHz carrier, which allows the dynamic range of EVM measurements to be as low as -48dB for 20MHz WLAN 802.11n measurements.

When the ultra-low phase noise option is used, the Model 2820A can tune to a new frequency in as little as 1ms.

Users can switch between maximum measurement performance and the maximum speed via software with this option.

In addition to the ultra-low phase noise option, the Model 2820A's displayed average noise level is better than -143dBm/Hz with the built-in pre-amp enabled.

In addition to the existing demodulation and signal analysis options for GSM, Edge, Edge Evolution, WCDMA, HSDPA, CDMA2000, WLAN and Wimax transmissions, the Model 2820A can now analyse 3GPP Release 7 HSPA+ signals with an optional personality.

Each preconfigured personality provides a robust set of measurements, instrument settings and test limits customised for the various standards.

These personalities are intended to save configuration time and minimise the potential for operator error.

The Model 2820A is among the latest additions to Keithley's multiple-input, multiple-output (MIMO) testing system solutions.

The 100Mbit/s data transfer rate allows researchers to conduct advanced MIMO studies in a number of areas, including channel sounding and beam forming.

Additionally, the Model 2820A offers time and phase synchronisation of MIMO signals.

Multiple Model 2820As can be synchronised to capture multiple transmission streams with high accuracy.

Signal acquisition synchronisation jitter is less than or equal to 250ps, so users can be confident that time delays between signal streams are the result of transmitter issues or channel conditions, rather than instrument latency, according to the company.

Keithley MIMO test configurations that include Model 2820A instruments can test MIMO devices with up to eight antennas.

MIMO signals can be generated and analysed using the company's Signalmeister RF communications test toolkit software and Model 2920 vector signal generators in conjunction with Model 2820As.

The Model 2820A will be introduced to the wireless test market at the International Microwave Symposium (IMS), a microwave conference.

The IEEE Microwave Theory and Techniques Society (MTT-S) IMS 2009 will be held in Boston, Massachusetts, as the centrepiece of Microwave Week 2009, scheduled to take place on 7-12 June.

Applications include research and development, product development and the production testing of a growing range of wireless handsets, modules and subassemblies, femtocells and picocells, wireless chipsets and wireless infrastructure equipment.

The Model 2820A's operating mode flexibility makes it suitable for research and education settings.

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