Accurately measuring the power in wideband signals used in 3G and pulsed systems requires a power meter with a high bandwidth. To address this market condition, the ML2487A (single-channel) and ML2488A (dual-channel) high speed peak power meters have been developed that feature 20 MHz channel bandwidth, which is a significant improvement over conventional power meters.

The increased bandwidth not only allows the power meters to accommodate existing 3G designs but also proposed 3G multi-carrier development. Complementing the wide bandwidth are numerous built-in features that simplify conducting power measurements on a variety of radio, navigation, aerospace and commercial wireless systems, including GSM, GPRS, CDMA 2000, CDMAOne, TD-SCDMA and WLAN.

The ML2487/8A power meters have been designed with trigger circuitry that allows only the power within a burst to be measured. A set of measurements, such as crest factor, peak power, built-in statistics (CCDF) and limits with pass/fail indication can also be made with the ML2487/8A. The measurement capability of the power meters make them well suited for use during design, manufacturing and installation. Figure 1 shows a typical burst power measurement.

In addition to the 20 MHz bandwidth, another unique feature of the ML2487/8A power meters is a large color display that makes analysis much easier. All measurement results can be displayed in either graphical or numerical readouts. Further simplifying signal analysis is an advanced graphical user interface.

The ML2487/8A power meters cover the 100 kHz to 65 GHz frequency range, depending on the sensor. Power measurement range is -70 to +20 dBm, again depending upon the sensor range (complete specifications are listed in Table 1 ). The 18 GHz CDMA sensor incorporates a switchable 5/20 MHz filter and a chopper that enables the sensor to be used down to -60 dBm. The 40 GHz radar and pulse sensor is primarily used for pulse measurements and has a dynamic range of -25 to +20 dBm. The ML2487/8A power meters also support Anritsu's full line of sensors, which includes diode sensors, thermal sensors and universal power sensors.

Table 1
ML2487/8A Specifications

Frequency range

100 kHz to 65 GHz, sensor dependent

Power measurement range (dBm)

-70 to +200 dependent upon sensor range

Instrumentation accuracy (%)


Offset range (dB)

-200 to +200

Display range (dB)

-200 to +200

Display resolution (dB)

selectable from 0.1 to 0.001

Internal trigger range (dBm)

-15 to +20 (selectable to -25)

Internal trigger level accuracy (dB)

1.0 typical

With a 20 MHz bandwidth and advanced sensors, the ML2487/8A can conduct accurate measurements on multicarrier and direct spread CDMA systems. The advanced triggering functions of the power meters enable them to capture CDMA slots for systems using non-continuous transmission. Peak, average and crest factor can be simultaneously shown on the display. The CCDF statistical function allows a system's peak power and stress to be measured under different channel code conditions.

The 20 MHz bandwidth of the power meters enables users to trigger and accurately measure the power in a WLAN transmission without having to add a compensation factor that historically had to be used with power meters with less bandwidth. The ML2487/8A's bandwidth and multiple marker function allow for accurate power measurements in pulsed systems such as those used in radar, navigation and aerospace systems. Multiple gates allow the power in a series of pulses to be individually and accurately measured.

The ML2487/8A can also perform highly accurate power measurements on 2.5G signals. The multiple gate measurement features of the power meters enable the accurate capture, display and measurement of GPRS systems. Users can select a choice of tabular readout or graphical profiles to measure the power in each individual slot of the GPRS frame. Measurement gate and fence features, coupled with triggering facilities, allow the power meters to conduct accurate measurements on GSM/EDGE signals. Simple pass/fail tests on those signals can also be performed by utilizing the mask and limit capability of the power meters.

Anritsu Co. , Richardson, TX (800) 267-4878, Circle No. 302