The Bird 4421 (often searched or miskeyed as IRD 4421) is a high-precision RF power meter designed for semiconductor processing and telecommunications applications. Highly regarded for its laboratory-grade accuracy, the 4421 operates with Bird's 4020 series power sensors to measure RF power, VSWR, and return loss in demanding environments.

Specifications

General

ParameterValue
InterfacesOptional GPIB (IEEE-488) or RS-232
Display4-1/2 digit LCD with backlight

Physical

ParameterValue
Power Supply115 / 230 VAC (±10%), 50/60 Hz, or 8 C-cell NiCd rechargeable batteries
Operating Temperature0 to 50 °C
Dimensions (W×H×D)312 x 108 x 310 mm
Weight5 kg
Rack Mount OptionSingle or dual 19" rack mounting kits available

RF Performance Specifications

ParameterValue
Frequency Range100 kHz to 1 GHz (sensor dependent)
Power Measurement Range300 mW to 10 kW (sensor dependent)

Measurement Accuracy & Resolution

ParameterValue
Power Measurement Accuracy±3% of reading (with 4020 series sensors)
VSWR Range1.0 to 199.9
Return Loss Range0.0 to 40.0 dB

Measurement Modes & Functions

ParameterValue
Measurement ModesForward Power (Watts or dBm), Reflected Power (Watts or dBm), VSWR, Return Loss (dB)

Sensor Compatibility & Control

ParameterValue
Compatible SensorsBird 4020 Series directional power sensors (e.g. 4021, 4022, 4024, 4025, 4027, 4028)

Display & User Interface

ParameterValue
Display UnitsW, dBm, SWR, dB

Environmental & Compliance

ParameterValue
Storage Temperature Range-20 to 70 °C
Operating Humidity95% maximum (non-condensing)

Power & Electrical Requirements

ParameterValue
AC Input Voltage Options115 VAC / 230 VAC nominal (rear panel switchable)
Battery Operating TimeUp to 8 hours with fully charged NiCd batteries

Power

ParameterValue
Power Consumption17 VA
AC Line Frequency50/60 Hz
Internal Battery TypeRechargeable Nickel-Cadmium (Ni-Cad)

Performance

ParameterValue
Overrange Indication120% of full scale
Instrument Accuracy±1% of reading (excluding sensor error)
Measurement RateApprox. 2 readings per second

Interfaces

ParameterValue
GPIB (IEEE-488) InterfaceOptional (field or factory-installable)
RS-232 InterfaceOptional (field or factory-installable)

Technology

Directional RF Power Measurement

Applications

Semiconductor manufacturing, RF transmitter maintenance, antenna system testing