Bird - The RF Experts
4421, Multifunction RF Power Meter

±1% Accurate RF Digital RF Power Meter

The Bird 4421 Multifunction Power Meter is a precision RF instrument that, while originally intended for general purpose laboratory applications where high accuracy is required, has found wide acceptance in semiconductor processing applications. The product is configured as a system, consisting of the 4421 and a precision power sensor selected for the application based upon maximum power and operating frequency.

  • ±1% Accuracy - Accomplished through the use of sensors with an automatic frequency compensation scheme, where the error contributions due to directional coupler frequency response characteristics are eliminated.
  • Wide Dynamic Range - The instrument will meet the full accuracy specification over a 35 dB dynamic range.
  • Excellent Measurement Repeatability - Typically <0.1%
  • Digital Display - Along with automatic VSWR calculation
  • Computer Interface - RS-232 and IEEE-488 standard
product specifications:
Item No
Item Name
Power Meter
Power Range
Sensor Dependent
Frequency Range
Sensor Dependent
VSWR Range
1.0 - 199.9 max
Forward and reflected power in W or dBm, VSWR, return loss in dB and min./max. values
Over range
Audible warning when RF power input exceeds 120% of sensor's maximum power range
Indication Display
LCD, 4½ digit display. Indicates mode, measurement units, battery condition, remote status, and signal increase/decrease. Self contained backlight
Operating Power
115/230 VAC, 50/60 Hz; 60W or 8 nickel metal hydride 1.2v cells, rechargeable
10 lbs (4.5 kg)
1 meter Latch-n-Lock Coiled Cable
Optional: IEEE-488 GPIB, RS-232
10.7"L x 12.25"W x 4.25"H
271 x 310 x 109 mm
4020 Series
3% Accurate, Directional Power Sensors
4027A Series
1% Accurate, Precision Directional Power Sensors
4028 Series
2% Accurate, Precision Power Sensors
Carrying Case - 4421 Wattmeter and Power Sensors
4421 Multifunction Power Meter Rack Mount Kit