Keysight N1914A EPM Series Dual-Channel Average RF Power Meter

Keysight N1914A EPM Series Power Meters

Do More With New-Generation EPM Series Power Meters

• Get up to four channels 1 to speed and simplify RF average power measurements
• Measure faster with improved measurement speed of 400 readings/sec with the Keysight Technologies, Inc. E-Series sensors
• View test results more easily with the industry’s first color LCD readout in an average power meter
• Go beyond GPIB with USB and LAN/LXI-C interfaces
• Automate frequency/power sweep measurements with the optional external trigger in/out feature
• Confirm battery power with a single-button push 2 — and get extra operating time with the optional spare battery
• Easily replace existing 436A, 437B and 438A meters with optional 43x code compatibility 3
• Enhance manufacturing test by connecting a large external monitor with the unique VGA output option

1 Additional two optional USB channels available 
2 Only applicable for models with battery option 
3 N1913A is backward compatible with the 436A and 437B, while N1914A is compatible with 438A.

Agilent Technologies is introducing the new N1913/1914A EPM Series power meter. It is a replacement for the E4418/4419B EPM Series power meter, and is based on the N1911/1912A power meter platform.

The N1913/1914A offers all average measurement capabilities, comparable to those of the E4418/4419B. However, the N1913/1914A is equipped with a faster digital signal processor (DSP) and microprocessor. Therefore, the N1913/1914A provides better performance than the E4418/4419B. One of the improvements is the measurement speed. When operated with Agilent E-Series power sensors, the N1913/1914A is able to achieve measurement speed up to 400 readings/second, compared to only 200 readings/second on the E4418/4419B.

The N1913/1914A provides enhanced features such as four-channel power measurement (with two additional Agilent USB power sensors connected to the USB master inputs), more connection flexibility (USB slave and LAN [LXI-Class C], on top of the existing GPIB), VGA video output, and smart battery pack.

Front Panel

Back Panel

N1913/1914A Operation Overview

The N1913/1914A operation block diagram shown in Figure 2 is applicable to all Agilent power meters. The meter works with both thermocouple and diode detector mounts, providing accurate RF average power measurement. The sensor converts the high frequency power to a DC or low frequency signal that the meter can then measure and relate to a certain RF power level.

The DC or low frequency signal from the sensor will be chopped, amplifi ed in AC-coupled system, and sent to the meter through the sensor cable. This process is necessary because it is diffi cult to transmit the DC signal across the cable, as the external DC noise will be easily coupled into the original signal. The chopper and AC amplifi er are embedded in the sensor itself. In the meter, the chopped signal is synchronously detected, de-chopped, and amplifi ed again. The calibrator precisely calibrates the signal measured by the meter to a power reference level.

The signal is fed into one of the multi-path blocks after the calibration process. Since most of the Agilent power sensors come with multi-path design, the low path and high path require different gain adjustments for accurate signal measurements. The signal will then be routed to data acquisition where the analog-to-digital converter (ADC) will execute the digital sampling. The essential measurement task is mostly done by the DSP. The microprocessor is the heart of the whole power meter operation, supervising not only data acquisition portion but also all the external interfaces (such as keypad input) and connectivity (remote communication and external triggering).

Operation block diagram of N1913 and 1914A

Faster Measurement Speed

High measurement speed is essential in high-volume manufacturing of RF and microwave components and systems. Faster testing time will improve your productivity by enabling you to test more devices in a shorter time.

Like all the Agilent power meters, there are three types of measurement speed settings for N1913/1914A: normal (by default), double (x2), and fast. In normal and double modes, full sensor functionality is available. In fast mode, averaging limits are disabled and set to 1 that allows fast measurement with uncompromised accuracy.

When the N1913/1914A operates with the E9300 or E4410 Series power sensors, the maximum achievable measurement speed is 400 readings/second in fast mode. The E4418/4419B can only achieve up to 200 readings/second. See Table 1 for specific comparisons of measurement speed.

Because of the SCPI backward compatibility, the same SCPI command for fast measurement mode can be used between the N1913/1914A and the E4418/4419B. Therefore, the N1913/1914A can be used directly by current E4418/4419B users without needing software recoding. For example, using the SCPI command of SENS1:SPE 200 sets the measurement speed on Channel 1 to 200 readings/second. But in reality, the N1913/1914A can achieve up to 400 readings/second in fast measurement mode while the E4418/4419B achieves 200 readings/second only.

Four-Channel Power Measurement

One of the application examples for multiple-channel power measurement is the two-port load-pull system shown in Figure 4. Channel A shows the incident power to the device under test (DUT), Channel B represents the reflected power, and Channel C shows the output power from the DUT. While monitoring all the power measurement results on the meter (Channels A, B, and C), the output tuner is adjusted until the reflected power is zero (Channel B). The gain and the power-added efficiency (PAE) can then be directly measured and displayed on the meter.