DESCRIPTION:

The Bird Technologies 4028A250K Directional Power Sensor is a high-power RF measurement sensor engineered for directional forward and reflected power measurement across a frequency span of 250 kHz to 400 kHz. As part of Bird’s 4028 Series Precision Directional Thruline Power Sensors, it delivers ±2 % accuracy at calibrated frequencies and power levels when used with compatible multifunction power meters such as the Bird 4421A Series. 

Designed for demanding RF environments — including high-power applications such as LCD, TFT, solar processing, and semiconductor tools — the 4028A250K offers stable, repeatable results with traceable calibration. Its directional architecture enables accurate measurement of both forward and reflected components, facilitating key RF system diagnostics such as VSWR, return loss, and power delivery verification. Calibration is traceable to the National Institute of Standards and Technology (NIST), providing confidence in measurement integrity for production and lab environments. 

Typical power range, connector selection, and calibration options are customer-specified and ordered separately, with the sensor calibrated as a matched unit with connectors to ensure published accuracy. 

Key specifications embedded in this description include the frequency range (250 kHz–400 kHz), power range (1.0 kW–20 kW), accuracy (±2 % at calibration), and standard performance indicators such as VSWR, insertion loss, and directivity that support precise RF measurement. 

Typical Use Suitability:
Ideal for high-power RF testing and diagnostics in areas such as semiconductor manufacturing, plasma processing, broadcast infrastructure, and other precision RF systems where accurate forward/reflected power data at low VHF frequencies is critical. 

Key Features

• Frequency range of 250 kHz to 400 kHz suitable for low-frequency high-power RF systems 

• High power coverage: 1.0 kW to 20 kW at typical calibrated power 

• Directional measurement: forward and reflected power sensing for comprehensive RF diagnostics 

• ±2 % accuracy at calibrated frequency and power levels, ±3 % outside calibration 

• High directivity:  28 dB minimum for improved measurement separation 

• Low insertion loss:  0.05 dB (connector dependent) 

• VSWR: Maximum ~1.05:1 at calibrated frequencies 

• Calibration traceable to NIST for measurement confidence 

• Designed for use with Bird 4421A Series multifunction power meters