Why Match Impedance?

All E&I amplifiers are designed with a 50 Ω output. When the load impedance differs, energy reflects back toward the amplifier—reducing efficiency and risking damage. Safe, effective power delivery requires impedance alignment:

• Known impedance? Use a Matching Transformer for direct conversion.
• Uncertain or variable loads? A Switchable Transformer provides flexibility across multiple tap settings.
• Unique requirements? We offer custom transformer designs to fit your exact specs.

Transformer Types at a Glance

Matching Transformers (JT Series)

When your system has a known load impedance, a matching transformer offers a straightforward and highly efficient way to optimize RF power transfer. E&I's JT Series transformers are designed to minimize reflected power, improve amplifier efficiency, and protect both the amplifier and load by ensuring proper voltage and current levels. These transformers are especially effective in applications like high-intensity focused ultrasound (HIFU), where consistent power delivery to a fixed load is essential for reproducible results.

Compact and passive, they're meant to be positioned close to the load—minimizing cable losses and reducing the effects of distributed capacitance. With broad impedance coverage and precision-wound construction, JT Series transformers support seamless system integration across a variety of lab and test setups.

• Impedance range: 3 Ω to 800 Ω
• Frequency band: 10 kHz - 10 MHz
• Power rating: 150 W, with custom high-power variants available
• Designed for low-loss performance and close-proximity placement to the load

Switchable Transformers (Locked-On Series)

When your test conditions vary—or your load impedance isn't known in advance—a fixed transformer won't cut it. That's where E&I's Locked-On Series shines. These switchable transformers allow users to select from multiple impedance tap settings, providing unmatched flexibility in lab, research, or field environments. Whether you're iterating through different transducers, adjusting for cable lengths, or fine-tuning a load with temperature or material variability, these transformers simplify the process while maintaining high efficiency.

Available models support a wide frequency range and up to 1 kW of peak power output, making them ideal for demanding RF energy applications. For added functionality, optional models include forward/reverse power display and hot-switching capability—allowing you to change tap settings without shutting down the system.

• Selectable impedance taps: 6 Ω to 800 Ω
• Frequency coverage: 500 kHz - 5 MHz
• Peak power handling: up to 1 kW
• Actively cooled for stable, continuous operation
• Optional “D” models with VSWR metering
• Optional “H” models with live-load switching (no power-down needed)