Measurement Capability For GSM Transmitter

Keithley Instruments has added an option for making GSM transmitter quality modulation measurements to its Model 2800 RF Power Analyzer.

Keithley Instruments has added an option for making GSM transmitter quality modulation measurements to its Model 2800 RF Power Analyzer.

The Model 2800 with GSM option is a high-throughput, cost-efficient solution that outperforms the high-end spectrum analyzers and communication test sets that are typically used to conduct RF power and transmitter modulation measurements.

Keithley's Model 2800 family provides a flexible, scalable, lower cost, and easier to use solution that increases throughput for manufacturers of mobile phones, RFIC power amplifiers, and related RF devices.

With the new GSM option, the Model 2800 measures whether a mobile phone transmitter or RFIC transmitter module conforms to GSM standards for modulated transmissions, capable of both calibrating the phone as well as assessing modulation quality in a single unit.

With these new features, the Model 2800 now performs all the transmitter modulation quality tests required by GSM manufacturers: Frequency Error Determines the differential or offset from the actual channel center frequency compared to the intended channel frequency, as assigned by the base station.

RMS and Peak Phase Error Assesses modulation quality by comparing the measured phase to the theoretical phase of the transmitted data stream of a modulated bit stream.

Time Mask Conformance Assesses if the power burst is properly confined to a 577-microsecond time slot and if burst rise and fall times are within limits defined by the GSM standard.

Output RF Spectrum In addition to measuring power in defined primary transmission channels, the Model 2800 with GSM option can measure output RF spectrum (ORFS), spurious power levels generated by the transmitter due to the effects of pulsed power transmission and the effects of the modulation method employed.

The Model 2800 RF Power Analyzer product family provides a number of advantages for RF device manufacturers seeking to make RF power measurements: " Rapid throughput to reduce test time and lower test cost.

The Model 2800 is the fastest instrument capable of making a set of channel power measurements at a number of power levels and at a number of frequencies (channels).

It is 30 percent faster than the fastest spectrum analyzer on the market in a form factor that occupies half the rack space and a price point at half the cost.

" Tremendous flexibility for manufacturers seeking to use the same test equipment to produce multiple product types, as the Model 2800 includes the ability to make power measurements for all major standards in the base product - no additional costly options required.

" Excellent repeatability and accuracy, ensuring high measurement integrity.

Better measurements can lead to tighter production limits and higher production line yields.

" Minimal complexity to support technician-level operation on the plant floor.

Unlike other products created particularly for design engineers rather than the production environment, the Model 2800 can be programmed with half the number of IEEE commands than comparable spectrum analyzers.

This simplicity minimizes the cost and time of switchover from existing test routines and equipment configurations.

Major features Industry standards for wireless phone transmission require measuring power in specified channel bandwidths.

The Model 2800 is designed for measuring power in the 800MHz and 900 MHz cellular band, as well as the higher DCS (1700MHz) and PCS (1800MHz) bands and the WCDMA (UMTS)/CDMA2000 bands.

The Model 2800 is optimized for testing RFIC wireless phone power amplifiers and wireless phones designed to the AMPS, CDMAOne, North American Digital Cellular (NADC), GSM, GPRS, EDGE, DCS, CDMA2000 1X, CDMA2000 3X, and WCDMA standards.

Market Factors The mobile phone industry faces challenges in many areas.

Design cycles have shrunk to fractions of a year, and production processes must be able to ramp production up/down rapidly.

This puts unprecedented demands on production test equipment, which must be flexible enough to test different wireless protocols and frequency bands as designs change.

Test equipment must be simple to operate to minimize the time needed to set up production lines.

It must increase throughput, which means it must be accurate, repeatable, easy to use, inexpensive for production applications, and small in physical size.

And at the same time, it must cost less to buy and to operate.

It was with these needs in mind that the Model 2800 was developed.

Unlike bulky and expensive general-purpose spectrum analyzers and communication analyzers, which are extremely versatile instruments intended for the R and D lab, the Model 2800 RF Power Analyzer includes only the capabilities required for wireless production testing, in a package optimized for high-speed production environments.

The result is a compact, ready-to-run instrument that is pre-configured with the appropriate frequencies, channel numbers, offsets, and other test parameters specific to the latest wireless standards.

The Model 2800 can be programmed and operated under computer control in automated test systems, eliminating unnecessary features like front panel graphic displays and extensive controls.

Advanced digital signal processing (DSP) technology allows the Model 2800 to perform multiple measurements and mathematical operations simultaneously at extremely high speed with minimal user programming.

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