STMicroelectronics STEVAL-TDR021V1

Overview

STEVAL-TDR021V1 from STMicroelectronics is a demonstration board built around the PD84008L-E 900 MHz LDMOS RF power transistor, designed for UHF 2-way portable radio transmitters. It delivers 5 W output power across 740–950 MHz with 11 ± 1.0 dB gain, 48–54% drain efficiency at 7.2 V supply, and infinite load mismatch tolerance.

For engineers reviewing the STEVAL-TDR021V1 datasheet, STEVAL-TDR021V1 pinout, STEVAL-TDR021V1 application, or STEVAL-TDR021V1 equivalent, this board serves as a validated RF power amplifier reference for rapid prototyping of handheld radios, field-deployable comms units, and narrowband UHF transmitter stages requiring thermal stability and harmonic suppression.

Technical Context

The board implements a single-stage Class AB RF power amplifier using the PD84008L-E in a common-source configuration with broadband matching networks. Input and output impedance are tuned via microstrip transmission lines and discrete LC components to achieve <−1 dB input return loss and stable 5 W saturated output across the full 740–950 MHz band.

Harmonic suppression is achieved through layout-controlled filtering and component selection: second-harmonic (H2) is −46 to −60 dBc and third-harmonic (H3) is −54 to −60 dBc at 26 dBm input, meeting ETSI EN 300 113 spectral mask requirements for land mobile radio.

Key Specifications

Availability

STEVAL-TDR021V1 is available at Aetrix Electronics and suitable for UHF portable radios, land mobile radio base stations, and emergency response communication systems requiring stable component supply and proven RF power stage validation.

Supply support for STEVAL-TDR021V1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, MCU, power, and RF solutions for industrial, automotive, and communications markets.

This board belongs to ST's STEVAL RF demonstration platform family, engineered to accelerate development of certified, thermally robust UHF transmitter subsystems for professional two-way radio equipment.

FAQ

What is the recommended DC bias condition for optimal performance?

Optimal operation requires V_DD = 7.2 V and I_DQ = 200 mA, as validated in Figures 2–5 of the official documentation. This bias point ensures 5 W output with 11 dB gain and >48% efficiency across 740–950 MHz while maintaining thermal stability without BeO-based substrates.

Can STEVAL-TDR021V1 be used with 50 Ω test equipment directly?

Yes - the board features SMA connectors on both RF input and output ports, each matched to 50 Ω. The input return loss exceeds −10 dB across the band, and output VSWR remains ≤1.5:1 into 50 Ω loads, enabling direct connection to vector network analyzers and signal generators without external matching.

Does the board include thermal management provisions?

Yes - the PD84008L-E is mounted on a 2-oz copper FR-4 PCB with optimized thermal vias and pad area per ST's layout guidelines. No external heatsink is required for intermittent duty, but continuous 5 W operation benefits from a 15 cm² aluminum heatsink attached to the transistor tab via thermal interface material.

Is the PD84008L-E on this board RoHS-compliant?

Yes - the PD84008L-E device is RoHS-compliant and halogen-free per STMicroelectronics' product change notification PCN-19-001. The STEVAL-TDR021V1 board itself uses lead-free solder and RoHS-compliant passives, including Murata GRM39 and Panasonic EEVHB series components.