BPM214: Bidirectional Power Meter for R9 Waveguide

BPM214 is a bidirectional power meter serving for accurate simultaneous measurement of incident and reflected powers up to 100 kW in high-power 900 MHz industrial applications using an R9 (WR975) rectangular waveguide. Each power meter is calibrated individually.

The BPM integrates a four-port directional coupler with the following components in each of its two channels:

  • Zero-bias Schottky diode detector
  • Low noise amplifier
  • 16-bit A/D converter for sampling detector voltages
  • 12-bit D/A converter providing the analog output
  • Microcontroller unit (MCU)
  • Optional display (common for both channels)

The MCU:

  • Controls A/D and D/A conversions.
  • Performs detector nonlinearity and temperature dependence correction.
  • Generates the following simultaneous outputs:
    • Two analog outputs, one (FWD) corresponding to the forward (incident) power; one (RFL) to the reflected power.
    • One digital output (RS232 or RS422 or CAN Bus).

The two analog outputs can be

  • voltage output 0 – 10 V; or
  • current output 4 – 20 mA.

The desired output type can be switched by the user. Both FWD and RFL outputs are of the same type. The output voltages/currents are linear functions of the microwave powers propagating in the forward and reverse directions of the parent waveguide. The digital outputs provide also internal power sensors temperatures. The RS232 and RS422 outputs have the form of easily readable text streams.

Configuration Options:
  • LCD Display: An LCD display that shows the incident (FWD) and reflected (RFL) powers as well as the internal power sensors temperatures. The powers are displayed both numerically and by bar indicators.
  • Precision Waveguide: A calibrated assembly consisting of a BPM fixed to a precisely machined parent waveguide with a standard (R9) or customized length.
  • BPM Cable: An extension cable, branching the DC power supply inputs VDC and GND to the power supply and TX, RX, GND pins to standard D9 RS232 connector
Specifications
Waveguide of Destination R9 (WR975), wall thickness 4mm
Frequency Range 895 – 925 MHz
Peak Working Power (options) 1 kW, 3 kW, 5 kW, 10 kW, 30 kW, 100 kW