Keithley unveils Model 2891-IQ Upconverter

Keithley Instruments, a provider of advanced electrical test instruments and systems, has introduced the Model 2891-IQ Upconverter, which provides comprehensive support for transceiver testing.

It achieves this by processing analogue I and Q baseband signals for testing a transceiver's transmitter, as well as processing analogue I and Q output signals for testing a transceiver's receiver.

The Model 2891-IQ converts single-ended baseband analogue I and Q signals from a signal generator into differential output signals to provide input signals for testing transceivers with differential baseband IQ inputs.

On the receiver side, it converts the receiver's down-converted differential I and Q signals into a modulated, up-converted signal for receiver performance testing by a radio-frequency (RF) signal analyser.

It speeds and simplifies designing transceiver test systems because it interfaces with both RF transceivers and with Keithley's Series 2900 RF vector signal generators and Series 2800 RF vector signal analysers.

The combination of the Model 2891-IQ with the Model 2920 vector signal generator and the Model 2820A vector signal analyser makes it easy to create a small, simple and cost-effective RF transceiver test system, according to Keithley.

The Model 2891-IQ contains gain adjustments so that it can interface with a variety of wireless chipsets and devices.

Additionally, the Model 2891-IQ can interface with RF transceivers with either single-ended or differential inputs.

Its EVM floor of -41dB, even for wideband 40MHz-bandwidth 802.11n signals, makes it possible to use the Model 2891-IQ when making high-quality modulation measurements.

This instrument's compact size makes it suitable for locating it close to the wireless device under test (DUT), which helps minimise loading, even on high-impedance devices, and maximises signal bandwidth.

Similarly, the selectable 50ohm/100kohm input impedance of the Model 2891-IQ's inputs allows it to connect to high-impedance devices with minimal signal loss.

The instrument's high-performance IQ modulator is said to provide excellent signal fidelity, allowing the DUT's receiver signals to be measured without noise floor or spurious signal interference from the instrument itself.

For example, the Model 2891-IQ's sideband suppression is less than -51dBc.

The instrument is controlled through a USB connection and programmed with a simplified SCPI command set.

A software control panel provides intuitive access to these commands.

A non-volatile EEPROM allows storing and recalling 10 user instrument states.

The Model 2891-IQ 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.

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