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Keithley's RF Vector Signal Generator Provides High Throughput and Low Phase Noise

Keithley Instruments Inc., a leader in advanced electrical test instruments and systems, announced that it has upgraded its popular RF Vector Signal Generator line for RF engineers with new capabilities that reduce signal generation times and enhance signal quality. In contrast with competitive signal generators, which typically force users to choose between best signal quality and maximum test throughput, the Model 2920A’s no-compromise design combines both capabilities in the same instrument. Patent-pending technology allows the Model 2920A RF Vector Signal Generator to support both frequency and amplitude switching rates that are significantly faster than any competitive system. Unlike systems optimized either for development or production, the Model 2920A is a cost-effective solution whether used on the bench for design verification testing or in production testing. To learn more, visit

The Model 2920A, which provides signal generation bandwidth options up to 80 MHz with a frequency range of either 10 MHz to 4 GHz or 10 MHz to 6 GHz, builds on the capabilities of Keithley’s Series 2900 signal generator line. It expands the Series 2900 line’s applications for testing wireless devices to today’s high throughput, complex modulation, and wide bandwidth wireless telecom standards, including LTE, GSM/EDGE, cdmaOne, cdma2000, W-CDMA, HSPA, HSPA+, LTE, WLAN, WiMAX, WiBro, TD-SCDMA, DVB (Digital Video Broadcast) and GPS (Global Positioning System).

The Model 2920A is optimized for calibrating and testing components such as amplifiers, filters and wireless receivers thoroughly over their full range of performance at exceptional speed. Several major advances allow it to provide substantially higher test throughput than earlier signal generation options:

• Fast frequency tuning: A new, patent-pending technique that ensures fast settling of phase-locked loop synthesizers allows the Model 2920A to tune to a new frequency on a device under test’s (DUT) operating band in 300 μs or less. Competitive products typically require 600 μs or longer to tune to a new frequency.

• Fast amplitude switching: The Model 2920A provides electronic attenuation and a fast-tracking, automatic level control loop to stabilize quickly on a new power level, which allows switching to a new amplitude in as little as 150 ms (compared to more than 500 μs for competitive generators). This fast settling time speeds testing a device over its full power handling range.

• Waveform switching in a single clock cycle: Because devices that operate on multiple standards require rapid switching between numerous complex signals during testing, the Model 2920A’s on-board arbitrary waveform generator includes a 100-megasample memory to hold large individual waveforms or multiple smaller ones. This deep memory, combined with the instrument’s speed-optimized list mode and a sequencer operating mode, supports switching from one waveform to another within a single processor clock cycle—even with waveforms based on different standards that use different modulation schemes.

• High speed signal file transfers: The Model 2920A offers a direct link from its DSP processing circuit block to an external PC via a USB 2.0 bus that maximizes operating speed. In this high-speed Desktop Control Panel operating mode, an external PC assumes control of the Model 2920A, just as if it were the instrument’s on-board processor controller. This mode supports transferring signal files from a PC directly into the Model 2920A’s arbitrary waveform memory at 100 Mb/sec for faster, simpler downloading of extremely large files (such as streaming video test signal files, signal files modified by channel models, and radar profile files). When combined with its high download speed and Keithley applications software, the Model 2920A can perform fast, efficient Dynamic Frequency Selection (DFS) conformance testing on WLAN access points. This test package allows verifying a device’s compliance with FCC, ETSI and TELEC requirements related to ensuring that WLAN access point transmissions detect and do not interfere with government radar signals (such as weather radar or air traffic control radar).

Users have the flexibility to create waveform files offline and download them into the Model 2920A’s arbitrary waveform memory using a USB memory stick or the GPIB or LAN interfaces. This transfer flexibility will be useful for those who prefer to employ third-party tools to create signal files, such as The MathWorks’ MATLAB® interactive programming environment.

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