VBA250 Series — 10 kHz to 250 MHz Class-A RF Power Amplifiers

Broadband, mismatch-tolerant RF power for EMC immunity and transducer drive
The VBA250 Series covers 10 kHz–250 MHz with true Class-A linearity and push-pull MOSFET output stages. The result is low distortion, high reliability, and unconditional tolerance of severe load mismatch—ideal for Bulk Current Injection (BCI), IEC 61000-4-6 conducted immunity, and demanding transducer/fixture drive. 

Key Technical Advantages

• Class-A architecture for lowest distortion in immunity testing and stable operation into difficult loads; no fold-back needed during high reflection, ensuring full output even with open/short conditions. 

• Push-pull MOSFET output topology suppresses even-order harmonics for cleaner spectra during test. 

• Wideband 10 kHz–250 MHz coverage across the series for conducted RF, BCI, TEM/stripline, and small fixture/antenna drive. 

• Unconditional stability & extreme VSWR tolerance (continuing at full power into open/short); suitable for varying BCI clamp impedances. 

• Integrated digital interfaces (select models), including USB/GPIB for control/monitoring and interlocks. 

Models & Core Specifications 

Specification	VBA250-80	VBA250-120	VBA250-200	VBA250-400	VBA250-600	VBA250-800	VBA250-1500A	VBA250-2500A
Picture
Typ. Performance Curve
Frequency Range	10 kHz–250 MHz	10 kHz–250 MHz	10 kHz–250 MHz	10 kHz–250 MHz	10 kHz–250 MHz	10 kHz–250 MHz	10 kHz–250 MHz	10 kHz–250 MHz
Type	Class-A; rugged push-pull MOSFET	Class-A; rugged push-pull MOSFET	Class-A; rugged push-pull MOSFET	Class-A; rugged push-pull MOSFET	Class-A; rugged push-pull MOSFET	Class-A; rugged push-pull MOSFET	Class-A; rugged push-pull MOSFET	Class-A; rugged push-pull MOSFET
Output VSWR Tolerance	∞:1, 100 % mismatch tolerant	∞:1, 100 % mismatch tolerant	∞:1, 100 % mismatch tolerant	∞:1, 100 % mismatch tolerant	∞:1, 100 % mismatch tolerant	∞:1, 100 % mismatch tolerant	∞:1, 100 % mismatch tolerant	∞:1, 100 % mismatch tolerant
Rated / Typical Power	CW ≥80W, P1dB ≥60W (>80W typ.)	CW ≥120 W, P1dB ≥90 W (120 W typ.)	CW ≥250W (10kHz-80MHz), ≥200W (80-250MHz), P1dB ≥200W (10kHz-80MHz),≥150W  (80-225MHz)	CW ≥400W (10kHz-80MHz), ≥360W (80-250MHz), P1dB ≥300W (10kHz-80MHz), ≥250W (80-250MHz)	CW ≥600W (10kHz-80MHz), ≥550W (80-250MHz), P1dB ≥500W (10kHz-80MHz), ≥400W (80-250MHz)	CW ≥800W (10kHz-80MHz), ≥650W (80-250MHz), P1dB ≥650W (10kHz-80MHz), ≥500W (80-250MHz)	CW ≥1500W (10kHz-80MHz), ≥1150W (80-250MHz), P1dB ≥1100W (10kHz-80MHz), ≥850W (80-250MHz)	CW ≥2500W (10kHz-100MHz), ≥1900W (100-250MHz), P1dB ≥2100W (10kHz-100MHz), ≥1300W (100-250MHz)
Gain (min)	50 dB	51 dB	54 dB	56 dB	63 dB	63 dB	63 dB	64 dB
Gain Flatness	±2 dB	±2 dB	±2 dB	±2 dB	±2 dB	±2 dB	±3 dB	±3 dB
TOI (typ)	58 dBm	61 dBm	64 dBm	66 dBm	67 dBm	67 dBm	69 dBm	70 dBm
Harmonics @ Linear Power	< –20 dBc	< –20 dBc	< –20 dBc	< –20 dBc	< –20 dBc	< –20 dBc	< –20 dBc	< –20 dBc
RF Input / Output Connectors	Type N (f)	Type N (f)	Type N (f)	Type N (f)	Type N (f)	Type N (f)	Input type N (f), output 7/16 (f)	Input type N (f), output 7/16 (f)
Input Power (Mains)	100-240V ac 45-63Hz,  <1kVA  IEC320	100-240V ac 45-63Hz,  <1kVA  IEC320	100-240V ac 45-63Hz,  <1kVA  IEC320	100-240V ac 47-63Hz, <1.5kVA  IEC320	184-264V ac 47-63Hz, <3kVA  IEC320	184-264V ac 47-63Hz, <3kVA  IEC320	3 phase 200-240V or 350-415V ac 47-63Hz, <6kVA IEC60309 plug	3 phase 200-240V or 350-415V ac 47-63Hz, <11kVA IEC60309 plug
Size & Weight	19-inch, 4U Case, 500mm Deep, 18kg	19-inch, 4U Case, 500mm Deep, 18kg	19-inch, 4U Case, 500mm Deep, 18kg	19-inch, 4U Case, 650mm Deep, 33kg	19-inch, 6U Case, 550mm Deep, 33kg	19-inch, 6U Case, 550mm Deep, 33kg	19-inch Rack, 16U Case, 800mm Deep, 150kg	19-inch Rack, 25U Case, 800mm Deep, 291kg
Interface	non, Opt. USB/GPIB Interface	non, Opt. USB/GPIB Interface	non, Opt. USB/GPIB Interface	USB/GPIB control; front panel display.	USB/GPIB control; front panel display.	USB/GPIB control; front panel display.	USB/GPIB control; front panel display.	USB/GPIB control; front panel display.
Notes	Front or Rear connectors	Front or Rear connectors	Front or Rear connectors	Front or Rear connectors	Rear connectors	Rear connectors	Rear connectors	Rear connectors

Common characteristics (series): Class-A operation, rugged push-pull MOSFET output stages, mismatch tolerance for EMC, broadband instantaneous bandwidth. 

EMC Applications & Standards Coverage

• Conducted RF Immunity (Coupling/Decoupling Networks): IEC/EN 61000-4-6.

• Automotive BCI/RI (clamp drive and forward-power control): ISO 11452-4, SAE J1113-4.

• Military Conducted Susceptibility: MIL-STD-461 CS114 BCI

• Avoionics Conducted Susceptibility: RTCA DO-160 Section 20 BCI testing

• Fixture/Transducer Drive: TEM/stripline fixtures, small RF antennas, current clamps, and injection probes across 10 kHz–400 MHz. 

Control, Monitoring & Protection (Model-Dependent)

• Local front-panel metering and interlocks; USB/GPIB remote control/monitoring on higher-power units (e.g., VBA400-260). 

• Designed for continuous duty in varying matches without fold-back, maintaining linear performance for repeatable immunity levels. 

Why Absolute EMC

Absolute EMC provides application-specific system design (BCI loops, clamps, CDN selection, power meters/couplers, LISNs), installation, and correlation guidance to IEC, ISO, SAE, DO-160, and MIL standards—so your amplifier integrates correctly with sensors, control, and calibration chains from day one.

What to Specify (Selection Guide)

1. Required test method & level (e.g., IEC 61000-4-6 level X, ISO 11452-4 forward power for clamp Y).

2. Fixture/transducer type and insertion loss.

3. Required linear output (P1dB) at the highest frequency of interest.

4. Available mains power and control interface needs (USB/GPIB).

5. Space/rack constraints and RF connectorization.

Typical System Block 

Signal source / RF generator → leveling & power meter/coupler → VBA 250 amplifier → CDN / BCI clamp/transducer → EUT, with reverse-power/VSWR monitoring and interlocks routed to the amplifier (∞:1 VSWR tolerance and unconditional stability on models like VBA400-260 simplify integration). 

Frequently Asked Questions

Q1. Will the amplifier survive a severe mismatch from my clamp or CDN?
Yes. The series is designed for EMC use with 100% mismatch tolerance, and models like the VBA250-2500 explicitly state that they operate at full power even with open/short circuits. 

Q2. Do I size by rated (P3dB) or linear (P1dB) power?
For immunity targets, size to P1dB at the top frequency to preserve linearity margin; see model-specific P1dB 

Q3. Can I remote-control the amplifier?
Yes—higher-power models provide USB/GPIB for enabling, metering, health, and interlock management. 

Ordering Information

• Models: VBA250-80, -120, -200, -400, -600, -800, -1500, -2500 (10 kHz–250 MHz series; note model-specific start frequencies per datasheet). 

• Included: Amplifier, mains cable, user manual; interface kit where applicable.

• Options/Accessories: RF directional couplers & power meters, BCI clamps, CDNs, TEM/stripline fixtures, control/monitoring packages.

• Warranty & Support: Provided by Absolute EMC with commissioning assistance and application support.