30 kHz to 18 GHz SMA female Bias Tee 50 V

30 kHz to 18 GHz SMA Bias Tee for RF and Microwave Applications

The BT-SF1801 is a broadband 50 Ω SMA bias tee designed to inject or extract DC voltage on an RF signal path in RF, microwave, test, and measurement environments. It allows engineers to combine RF and DC on a single coaxial line while keeping the DC supply path separated from the RF input path.

With a frequency range from 30 kHz to 18 GHz, this SMA bias tee is suitable for wideband laboratory setups, production test systems, and RF subsystem validation. The component features SMA female connectors on the RF port, RF + DC port, and DC port, supporting straightforward integration into common coaxial measurement chains and microwave assemblies.

Typical Applications

• DC bias injection for RF amplifiers, low-noise amplifiers, gain blocks, active antennas, and microwave modules.
• Vector network analyzer measurements where the device under test requires DC bias during S-parameter characterization.
• RF and microwave laboratory setups requiring separation between the RF signal path and the DC supply line.
• Production test fixtures for biased RF components, modules, and coaxial assemblies.
• System-level troubleshooting and validation where DC power must be applied without modifying the main RF interconnection.

Key Features

• Broadband frequency coverage from 30 kHz to 18 GHz.
• 50 Ω impedance for standard RF and microwave coaxial systems.
• SMA female connectors on RF, RF + DC, and DC ports.
• DC voltage rating up to 50 V.
• DC current rating up to 700 mA.
• Specified VSWR ≤1.70 for controlled RF matching across the operating band.
• Insertion loss ≤2 dB to support efficient RF signal transmission.
• RF-to-DC isolation ≥35 dB for separation between signal and bias paths.
• Average power rating up to 5 W.
• Operating temperature range from -55 °C to +85 °C.
• Compact aluminum housing with conductive oxidation finish.

Why Use a Bias Tee?

A bias tee is used when an active RF device needs DC power while carrying an RF signal through the same coaxial connection. In a typical configuration, the RF port connects to the RF source or measurement instrument, the RF + DC port connects to the biased device, and the DC port connects to the external power supply or bias control circuit.

This configuration is useful in measurement chains where the RF path must remain clean and repeatable while DC supply conditions are applied separately. The BT-SF1801 supports this requirement with broadband operation, defined RF performance, and a compact coaxial design suitable for bench-top and system-level environments.

Selection Guidance

Before selecting the BT-SF1801, verify that the required operating frequency, DC voltage, DC current, RF average power, connector interface, and temperature range are compatible with the target application. For replacement or form-fit-function evaluation, also compare the SMA connector gender, port configuration, insertion loss budget, isolation requirement, and mechanical dimensions with the existing component or system design.

For complete specifications, mechanical drawing, and typical test data, refer to the product datasheet.