Microwave Journal

Keithley Offers Model 2820A RF Vector Signal Analyzer

June 12, 2009

Keithley Instruments Inc., a leader in advanced electrical test instruments and systems, announced that it has upgraded its popular RF Vector Signal Analyzer line with new capabilities that reduce signal acquisition and measurement times. The new Model 2820A RF Vector Signal Analyzer, which provides a 40 MHz signal acquisition bandwidth with a frequency range of either 400 MHz to 4 GHz or 400 MHz to 6 GHz, builds on the capabilities of Keithley’s Series 2800 signal analyzer 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 major advances allow the Model 2820A to provide substantially higher testing speed:

Fast frequency switching: The Model 2820A can tune to a new frequency in just 250μs, which is faster than any signal analyzer on the market. That significantly reduces total transmitter test time when testing a device that operates over a wide frequency band or multiple frequency bands.

High speed data transfers: A new technique allows transferring large amounts of demodulated I,Q data from the instrument to a PC for analysis via the USB bus at speeds better than 100 megabits per second – that’s 25 times faster than the previous generation of analyzers. 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 data is transferred directly from the DSP-processing blocks to the 100Mb/sec USB bus. In this mode, the instrument’s front panel display is disabled and the information is displayed 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 <700µs per measurement. The Model 2820A also has the ability to post-process continuous blocks of data bursts, so 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.

Fast sequence testing: The Model 2820A employs a single-command, multi-operation technique to minimize transmitter calibration and performance test times. With a single setup, a wide 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 I, Q offset, are all included in a single data capture operation.

The Model 2820’s combination of fast frequency tuning, a desktop control panel, 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.

Just as important, this enhanced speed does not compromise measurement performance; in fact, it has been improved significantly:

Ultra-low phase noise option: A new synthesizer design allows the Model 2820A to provide excellent low phase noise performance. For example, the phase noise is <140 dBc/Hz at a 300 kHz offset on a 2 GHz carrier, which allows the dynamic range of EVM measurements to be as low as -48 dB for 20 MHz 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.

Displayed average noise level: In addition to the ultra-low phase noise option, the Model 2820A’s displayed average noise level is better than -143 dBm/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 analyze 3GPP Release 7, HSPA+ signals with a new optional personality. Each preconfigured personality provides a robust set of measurements, instrument settings, and test limits customized for the various standards. These personalities save configuration time and minimize the potential for operator error.

Continuing Technical Leadership in MIMO Testing. The Model 2820A is among the latest additions to Keithley’s MIMO (Multiple-Input, Multiple-Output) testing system solutions. The new 100Mb/sec data transfer rate allows researchers to conduct advanced MIMO studies in such areas as channel sounding and beam forming. Furthermore, the Model 2820A offers unprecedented time and phase synchronization of MIMO signals. Multiple Model 2820As can be synchronized to capture multiple transmission streams with extremely high accuracy. Signal acquisition synchronization jitter is ≤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. Keithley MIMO test configurations that include Model 2820A instruments can test MIMO devices with up to eight antennas. MIMO signals can be easily generated and analyzed by using Keithley’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), the world's premier microwave conference. In 2009, the IEEE Microwave Theory and Techniques Society (MTT-S) International Microwave Symposium 2009 (IMS 2009) will be held in Boston, MA, as the centerpiece of Microwave Week 2009, scheduled from June 7 through June 12.