RF component testing

Your amplifier design optimization and validation challenge

Testing power amplifiers spans from initial wafer fabrication to final integration into the targeted system application.

Development phase: Validation and optimization

During the development phase of power amplifiers, several key aspects must be validated and optimized:

• Performance Validation: The first step is to confirm the amplifier’s basic performance, ensuring it operates reliably within its intended specifications. Advanced characteristics, such as linearity and modulation distortion, are analyzed to assess signal fidelity. This process includes verifying the effectiveness of performance-enhancement techniques, like linearization using Digital Pre-Distortion (DPD), which helps minimize distortion in complex modulation schemes.
• Energy Efficiency: Energy efficiency is a primary focus in amplifier testing, as it represents a major competitive differentiator and is critical to a product’s market success. Efficient amplifiers contribute to longer battery life in portable devices and reduced operating costs in infrastructure applications.
• Design Optimization: Fundamental design decisions are evaluated and refined, including the selection of the most suitable semiconductor technology for the target application. The process also involves investigating and fine-tuning circuit topologies, such as the Doherty design, to achieve optimal performance.
• Doherty power amplifier design: The Doherty amplifier is a specialized architecture known for its advanced efficiency enhancement capabilities, especially when amplifying signals with high peak-to-average power ratios. Characterizing and optimizing Doherty amplifiers requires advanced test solutions that can precisely control the amplitude and phase of input signals for both carrier and peaking amplifiers to optimize their interaction, as well as analyze their combined performance. Effective Doherty amplifier design testing is essential for achieving high efficiency and reliability in modern communications systems.

Production phase: Ensuring Quality and Throughput

In production, it is crucial to ensure performance, reliability, and meeting stringent specifications across the value chain and to let only good parts go to the next step for being packaged and shipped to customers.

• On-Wafer Testing:
  Early qualification of a device is crucial for minimizing costs if any issues arise. Testing begins at the wafer level, where either the device structure itself or dedicated test structures on the same wafer are verified to simplify the process.
  Process monitoring and basic tests are conducted using both DC and RF metrics to identify successful wafer runs and isolate faulty devices. Since device behavior can change after packaging, only fundamental RF tests, such as measuring S-parameters for gain and matching, are meaningful at this stage. In many cases, pulsed test scenarios are preferred to avoid significant self-heating of the test devices. With many devices present on a single wafer, efficient testing strategies are essential to keep test times manageable.
• Full device validation:
  Once devices are packaged, comprehensive validation becomes mandatory to ensure that only high-quality products reach end customers. The validation process is tailored to the amplifier type and its intended use case, involving both continuous wave (CW) and modulated signal tests. These tests confirm that the device meets its promised specifications and performs reliably in real-world applications.

Our RF power amplifier testing solutions

Rohde & Schwarz offers a comprehensive set of test instrumentation optimized to address the challenges in RF power amplifier validation. Dedicated solutions are available for CW and modulated test for development with enhanced features and maximized RF performance in dynamic range and modulation quality. On the other side, throughput optimized instrumentation helps you to meet the production and characterization needs.

Rohde & Schwarz offers a comprehensive set of test instrumentation optimized to address the challenges in RF power amplifier validation. Dedicated solutions are available for CW and modulated test for development with enhanced features and maximized RF performance in dynamic range and modulation quality. On the other side, throughput optimized instrumentation helps you to meet the production and characterization needs.

• Vector network analyzers (VNA) provide a wide test range, with a single connection enabling measurements from S-parameters through to gain compression over frequency, as well as linearity validation. The use of pulsed signals during testing helps prevent device overheating, which is particularly important when amplifiers are not yet equipped with proper cooling.
• Load pull systems offer deeper insights into amplifier behavior and facilitate optimization for varying operating conditions. They also enable precise adjustment of termination for harmonic frequencies, ensuring the amplifier performs efficiently and reliably across its intended range.
• Modulation tests focus on key metrics for linear signal transmission, such as error vector magnitude (EVM) and adjacent channel leakage ratio (ACLR), which quantify signal quality and unwanted spectral regrowth. Modulation testing often includes linearization techniques to validate optimal operating conditions. Rohde & Schwarz’s industry-leading vector signal generation and analyzer solutions deliver unique features and the most comprehensive test capabilities available.
• A wide range of power supplies is essential, as active devices like RF power amplifiers require multiple power lines for supply and biasing. Rohde & Schwarz offers various power supplies tailored to different technologies, including high-power and high-voltage solutions for next-generation GaN amplifiers, as well as cost-efficient options for standard biasing needs.
• Dedicated throughput and cost optimized solutions are available for production and characterization environments. Rohde & Schwarz provides VNAs and vector component testers designed to maximize throughput and minimize costs, ensuring efficient and reliable testing for large volumes of devices.