Vaunix TS-LDA-203B Compact Miniature RF Digital Attenuator

Overview

The Vaunix TS-LDA-203B is a compact, USB- and Ethernet-enabled digital step attenuator engineered for precision RF signal conditioning across demanding laboratory, production, and field-deployable test environments. Operating over a continuous 1–20 GHz frequency range, it delivers bidirectional 50 Ω impedance-matched attenuation with a total dynamic range of 63 dB and fine 0.5 dB resolution steps. Built on solid-state GaAs MMIC technology, the TS-LDA-203B eliminates mechanical wear associated with electromechanical relays—ensuring long-term stability, repeatability (< ±0.05 dB typical step accuracy), and >1 million cycle lifetime. Its fully programmable architecture supports both standalone operation via embedded web GUI and deep integration into automated test systems (ATE) through industry-standard interfaces. Designed to meet the evolving requirements of modern wireless infrastructure validation—including Wi-Fi 6E, 5G NR FR1/FR2 coexistence testing, LTE-A carrier aggregation, and microwave radio link characterization—the TS-LDA-203B serves as a foundational component in signal integrity verification, channel emulation, and receiver sensitivity calibration workflows.

Key Features

• Solid-state GaAs-based design ensures high reliability, low insertion loss (typ. < 3.5 dB at 20 GHz), and exceptional amplitude repeatability across temperature and time
• Bidirectional 50 Ω matched architecture enables use in both forward and reverse signal paths without VSWR degradation
• Dual control interface: USB 2.0 (Class CDC) and 10/100BASE-T Ethernet with configurable static IP or DHCP support
• Embedded password-protected web GUI accessible via any standards-compliant browser; no client software required
• Onboard microcontroller supports programmable attenuation ramping, custom attenuation profiles, and timed step sequencing
• USB bus-powered operation (no external PSU needed); compatible with powered USB hubs for multi-unit synchronization
• Compact footprint (102 × 64 × 25 mm) and lightweight aluminum housing optimized for benchtop, rack-mounted, or portable ATE integration

Sample Compatibility & Compliance

The TS-LDA-203B maintains RF performance consistency across a wide range of signal types—including modulated OFDM, QAM, and pulsed waveforms—without introducing measurable group delay variation or harmonic distortion (typ. < –60 dBc spurious output). It complies with CE marking requirements (EMC Directive 2014/30/EU, RoHS 2011/65/EU) and meets FCC Part 15 Subpart B Class B emission limits. While not certified to MIL-STD or IEC 61000-4-x immunity levels out-of-box, its robust PCB layout and shielded enclosure support deployment in GLP-compliant test labs where traceability and environmental stability are documented per ISO/IEC 17025. The device does not require periodic recalibration under normal operating conditions; however, users performing metrology-grade measurements may implement end-to-end system verification using NIST-traceable power sensors.

Software & Data Management

Vaunix provides comprehensive cross-platform software support including: a native Windows GUI application with real-time attenuation sweep visualization; Windows DLL and .NET wrapper libraries; Linux command-line utilities and C/C++ header files; official Python bindings (PyPI package vaunix-lan) with Jupyter notebook examples; and LabVIEW 2015+ drivers with full VI library documentation. All SDKs include source-level access to low-level SCPI-compatible command sets (e.g., :ATT:VAL 32.5, :ATT:STEP:INC 0.5). Audit trails for attenuation changes can be logged externally via timestamped API calls; while the device itself does not store logs internally, its Ethernet interface supports integration with centralized test management systems compliant with FDA 21 CFR Part 11 when deployed behind authenticated enterprise networks.

Applications

• Receiver sensitivity and blocking performance evaluation in 5G NR and Wi-Fi 6E base station and UE testing
• Fading channel simulation in MIMO OTA test chambers using synchronized multi-attenuator arrays
• Dynamic range validation of spectrum analyzers, vector signal analyzers, and RF front-ends
• Automated gain control (AGC) loop characterization and linearity testing of LNA and PA modules
• Production-line RF path calibration for SDR platforms, satellite communication terminals, and radar subsystems
• Education and R&D labs requiring reproducible, scriptable RF stimulus generation without RF switch matrix complexity

FAQ

Is the TS-LDA-203B suitable for use in safety-critical or aerospace applications?
The TS-LDA-203B is designed for commercial and industrial test environments. It is not qualified to DO-160, MIL-STD-810, or AS9100 standards; users requiring such certifications must perform independent qualification testing.
Can multiple TS-LDA-203B units be controlled simultaneously from one PC?
Yes—each unit is assigned a unique serial number and supports simultaneous USB/Ethernet addressing. The SDK includes multi-device enumeration and synchronous command dispatch functions.
Does the device support IEEE-488 (GPIB) or RS-232 interfaces?
No—only USB and Ethernet interfaces are provided. GPIB functionality is not implemented, and no adapter-based bridging is officially supported.
What is the maximum input power rating, and does it vary with frequency?
Maximum average input power is +27 dBm (0.5 W) up to 12 GHz, derating linearly to +23 dBm (0.2 W) at 20 GHz. Peak pulse power handling is specified separately in the datasheet.
Is firmware upgrade capability available, and how is it performed?
Firmware updates are delivered via Vaunix-provided Windows utility or HTTP POST to the device’s web server; updates preserve user-configured network settings and calibration offsets.