Linear RF power amplifiers for EMC immunity testing, 10kHz to 6GHz
Laplace supplies linear RF power amplifiers for EMC immunity testing across the 10kHz to 6GHz range. The Laplace RFA range spans 15W to 400W, with higher power and microwave options available where the application requires them.
Every RFA model operates in Class A. That matters for immunity testing, where the amplifier drives antennas, CDNs and test cells whose impedance varies considerably across the band. Class A gives low distortion and unconditional stability, and all RFA models tolerate infinite VSWR with no fold-back protection fitted or required. The amplifier holds its output regardless of load mismatch, so the test level stays where you set it.
USB, GPIB and Ethernet remote control is included as standard on every model, along with rack and bench mount fixtures and a dual safety interlock.
Laplace has supplied EMC test equipment from Norfolk since 1989. Amplifiers are specified, supplied and supported directly by our engineers.
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- Class A operation across the full frequency range
- Infinite VSWR tolerance with no fold-back protection fitted or required
- Five amplifier families covering 10kHz to 6GHz
- 15W to 400W, with higher power available
- USB, GPIB and Ethernet remote control included as standard
- Dual safety interlock, short circuit and open circuit to mute
- Type N connectors, 50 ohm output impedance
- Rack and bench mount fixtures supplied
Jump to an amplifier family
Got a higher frequency or power requirement? Get in touch for our bespoke solutions
LINEAR
Class A operation across the full band gives very low distortion and unconditional stability. Immunity test signals carry 80% amplitude modulation, and a linear amplifier reproduces that envelope accurately so the level at the EUT is the level you set.
ROBUST
Every model tolerates infinite VSWR with no fold-back protection fitted or required. Antennas, CDNs and test cells present a load that changes across the band, and the amplifier holds its output regardless.
BROADBAND
Continuous instantaneous frequency coverage within each family, with no band switching. Five families cover conducted immunity, radiated immunity and the wireless immunity bands to 6GHz.
SUPPORTED
Specified, supplied and supported directly by Laplace engineers in Norfolk. We size the amplifier against your standard, level and transducer rather than selling from a catalogue.
Choosing an amplifier for EMC immunity testing
Three questions decide the amplifier: which frequency range the standard calls for, what level you need to reach, and what you are driving.
Conducted immunity (IEC 61000-4-6)
Conducted immunity runs from 150kHz to 80MHz, with test levels of 1V, 3V and 10V applied through a CDN, EM clamp or current injection probe.
Power requirements are modest, but linear power is the figure that counts, not saturated power. The test signal carries 80% amplitude modulation at 1kHz, which adds to the peak. An amplifier running near compression will distort that envelope and the level at the EUT will not be what the meter says.
The RFA 230 covers 150kHz to 230MHz, matching the range of the standard with headroom above it. The RFA 250 extends down to 10kHz where automotive or military variants of the test demand it.
Radiated immunity (IEC 61000-4-3)
Radiated immunity covers 80MHz to 1GHz, extended to 6GHz for wireless immunity testing. Power depends heavily on the transducer and the test distance.
The RFA 1000-45 covers 10kHz to 1000MHz at 45W and is specified for test cell and CDN driving. The RFA 1000-80 provides 80W from 80MHz to 1000MHz. Above 1GHz, the RFA 1060 series covers 1000MHz to 6000MHz at 15W to 60W using wideband GaN output stages.
A compact test cell reaches useful field strengths from tens of watts because the field is developed internally rather than radiated across a chamber. A 3m semi-anechoic chamber testing to the same level needs considerably more.
Automotive and military testing
ISO 11452 and DEF STAN 59-411 extend below the commercial frequency limits and often call for higher levels than commercial standards.
The RFA 250 starts at 10kHz and provides up to 400W, making it the highest power option in the range for low frequency conducted work.
The RFA 400 provides continuous coverage from 10kHz to 400MHz in a single unit, which spans the bands used by most automotive conducted immunity methods without a changeover.
How much amplifier power do you need?
For radiated immunity in a chamber, the field strength at the EUT follows from the power delivered to the antenna, the antenna gain and the separation distance. Doubling the distance requires four times the power for the same field strength, and the gain of the antenna varies across its band, so the worst case usually sits at one end of the frequency range rather than in the middle.
Specifying an amplifier is rarely a matter of reading one number off a datasheet. If you send us the standard, the test level and the transducer you are driving, we will size the amplifier for you.
Two points worth more than any calculation
Specify against linear power, not saturated power. Saturated power tells you where the amplifier stops. Linear power, usually quoted at 1dB gain compression, tells you where it still behaves. With 80% amplitude modulation applied, budget for the peak rather than the carrier.
Account for cable and coupler losses. Long runs to a chamber and directional couplers in the forward path both consume amplifier output before it reaches the antenna. A system that looks adequate on paper can fall short at the EUT.
The Laplace RFA amplifier range
Five amplifier families covering 10kHz to 6GHz. All models are Class A, 50 ohm, with Type N connectors, dual safety interlock and USB, GPIB and Ethernet remote control included as standard.
RFA 230 Series: 150kHz to 230MHz, 22W to 80W
Matched directly to the IEC 61000-4-6 conducted immunity frequency range, with headroom above it. Three power variants share a push-pull MOSFET platform in a compact 3U case, giving extra even-order harmonic suppression across the full range.
Where conducted immunity is the primary requirement and the test levels are the standard 1V, 3V and 10V, this is the most cost-effective family in the range.
| Model | RFA 230-22 | RFA 230-35 | RFA 230-80 |
| Rated output power | 22W Min (27W typical) |
35W Min (37W typical) |
80W Min (90W typical) |
| Output power at 1dB gain compression | 16W Min (20W typical) |
25W Min (30W typical) |
70W Min (80W typical) |
| Gain | 46dB Min | 46dB Min | 50dB Min |
| Third order intercept point | 54dBm | 55dBm | 58dBm |
| Harmonics | Better than -20dBc at 16W | Better than -20dBc at 25W | Better than -20dBc at 70W |
| Supply power | <120VA Max | <140VA Max | <400VA Max |
| Dimensions | 19″, 3U 400mm deep |
19″, 3U 440mm deep |
19″, 3U 440mm deep |
| Weight | 12kg | 12kg | 13kg |
RFA 250 Series: 10kHz to 250MHz, 80W to 400W
The highest power family in the range and the broadest low frequency coverage. Four power variants share a single push-pull MOSFET platform, giving extra even-order harmonic suppression across the full range. Suited to conducted immunity across commercial, automotive and military limits, and to test cell driving at the low end of the radiated band.
The RFA 250-400 additionally provides a front panel display and rear panel connectors.
| Model | RFA 250-80 | RFA 250-120 | RFA 250-200 | RFA 250-400 |
| Rated output power | 80W Min | 120W Min | 250W Min (10kHz-80MHz) 200W Min (80-250MHz) |
400W Min (10kHz-80MHz) 360W Min (80-250MHz) |
| Output power at 1dB gain compression | 60W Min | 90W Min | 200W Min (10kHz-80MHz) 150W Min (80-225MHz) |
300W Min (10kHz-80MHz) 250W Min (80-250MHz) |
| Gain | 50dB Min | 51dB Min | 54dB Min | 56dB Min |
| Third order intercept point | 58dBm | 61dBm | 64dBm | 66dBm |
| Harmonics | Better than -20dBc at 60W | Better than -20dBc at 80W | Better than -20dBc at 150W | Better than -20dBc at 150W |
| Supply power | <1kVA Max | <1kVA Max | <1kVA Max | <1.5kVA Max |
| Dimensions | 19″, 4U 500mm deep |
19″, 4U 500mm deep |
19″, 4U 500mm deep |
19″, 4U 650mm deep |
| Weight | 18kg | 18kg | 18kg | 33kg |
RFA 400 Series: 10kHz to 400MHz, 30W and 80W
Continuous instantaneous coverage from 10kHz to 400MHz in two power variants, built on the same push-pull MOSFET platform in a 3U case.
Useful where a single amplifier needs to span conducted immunity and the lower automotive radiated bands without a changeover, and where the extra frequency headroom above 230MHz is worth having.
| Model | RFA 400-30 | RFA 400-80 |
| Rated output power | 30W Min (37W typical) | 80W Min (90W typical) |
| Output power at 1dB gain compression | 20W Min (30W typical) | 60W Min (70W typical) |
| Gain | 46dB Min | 48dB Min |
| Third order intercept point | 55dBm | 58dBm |
| Harmonics | Better than -20dBc at 20W | Better than -20dBc at 50W |
| Supply power | <140VA Max | <400VA Max |
| Dimensions | 19″, 3U, 440mm deep | 19″, 3U, 440mm deep |
| Weight | 12kg | 13kg |
RFA 1000 Series: up to 1000MHz, 30W to 80W
Four models covering the radiated immunity band to 1GHz, with the low frequency limit matched to the application rather than fixed across the family. Push-pull LDMOS output stages throughout, with GaAs driver stages on three models to minimise power degradation at the top of the band.
The RFA 1000-45 covers 10kHz to 1000MHz in a single unit and is specified for test cell and CDN driving. The RFA 1000-80 is optimised for power delivery into high VSWR loads in a compact 4U case.
| Model | RFA 1000-30 | RFA 1000-35 | RFA 1000-45 | RFA 1000-80 |
| Frequency range (instantaneous) | 80-1000MHz | 1-1000MHz | 0.01-1000MHz | 80-1000MHz |
| Rated output power | 30W Min (40W typical) |
35W Min (45W typical) |
45W Min (0.01-400MHz) 35W Min (400-1000MHz) |
80W Min |
| Output power at 1dB gain compression | 20W Min (25W typical) |
20W Min (25W typical) |
35W Min (0.01-400MHz) 20W Min (400-1000MHz) |
60W Min |
| Gain | 50dB Min | 50dB Min | 50dB Min | 50dB Min |
| Third order intercept point | 57dBm | 57dBm | 57dBm | 58dBm |
| Supply power | 300VA Max | 300VA Max | 300VA Max | <1kVA Max |
| Dimensions | 19″, 3U 440mm deep |
19″, 3U 440mm deep |
19″, 3U 440mm deep |
19″, 4U 500mm deep |
| Weight | 13kg | 13kg | 13kg | 18kg |
RFA 1060 Series: 1GHz to 6GHz, 15W to 60W
Wideband GaN output stages combined using proprietary quadrature hybrid techniques to minimise loss. Four power variants cover the wireless immunity band as a single continuous instantaneous frequency range, with no band switching required across the sweep.
Class A operation with infinite VSWR tolerance at any phase, and no fold-back protection fitted or required.
| Model | RFA 1060-15 | RFA 1060-25 | RFA 1060-40 | RFA 1060-60 |
| Rated output power | 15W | 25W | 40W | 60W |
| Output power at 1dB gain compression | 10W | 20W | 30W | 50W |
| Gain | 43dB Min | 46dB Min | 47dB Min | 49dB Min |
| Third order intercept point | 51dBm | 54dBm | 56dBm | 58dBm |
| Supply power | 150VA | 300VA | 450VA | 1.5kVA |
| Dimensions | 19″, 3U 500mm deep |
19″, 3U 500mm deep |
19″, 3U 500mm deep |
19″, 3U 600mm deep |
| Weight | 6kg | 7kg | 12kg | 15kg |
Higher power and microwave requirements
The RFA range covers the majority of commercial EMC immunity testing. Where an application needs more, we supply amplifiers to 20kW from 2 to 30MHz, 5kW from 80MHz to 1GHz, 2kW from 1 to 4GHz, and coverage extending to 40GHz.
These are specified against the individual requirement rather than sold from a catalogue. Tell us the frequency range, the test level and the transducer, and we will quote the appropriate unit.
Let us know your requirements in the form below, or email: tech@laplace.co.uk
RFA amplifiers with LaplaCell test cells
Laplace manufactures the LaplaCell range in-house alongside supplying the RFA amplifiers, so both halves of an immunity test setup come from one supplier with one point of support. A test cell develops its field internally rather than radiating across a chamber, so the amplifier power required is considerably lower than an equivalent chamber test. The RFA 1000-45 is specified for test cell and CDN driving.
Laplace also supplies GTEM systems where more suitable for the application. If you are unsure which approach fits your requirement, contact us to discuss it.
Frequently asked questions
Saturated power is the maximum the amplifier will produce. Linear power, usually quoted at 1dB gain compression, is the maximum it will produce without distorting.
Immunity testing uses modulated signals rather than a plain carrier, so the peak of the envelope is what matters. Specify against linear power, and treat saturated power as a headroom figure rather than a working one.
Antennas, CDNs and test cells present a load that changes across the frequency band. A Class A amplifier with unconditional stability and full VSWR tolerance holds its output regardless, so the test level remains correct.
Amplifiers with fold-back protection reduce output when the load mismatches, which changes the level at the EUT without warning. No RFA model has fold-back protection fitted, and none requires it.
The RFA 230 covers 150kHz to 230MHz and matches the frequency range of the standard directly. Power depends on your test level and the coupling device. For most 3V and 10V testing through a CDN, the 22W or 35W variants are sufficient.
Where the test extends below 150kHz for automotive or military work, the RFA 250 starts at 10kHz and offers considerably more power.
It depends on the transducer, the test distance and the antenna gain at the frequency concerned.
A compact test cell will reach that level from tens of watts because the field is developed internally. A 3m chamber test needs substantially more, and the worst case usually sits at one end of the antenna’s frequency range rather than in the middle. Send us your test setup and we will size it.
Yes. USB, GPIB and Ethernet remote control is included as standard on all RFA models, along with rack and bench mount fixtures and a dual safety interlock with short circuit and open circuit mute.
The RFA 1000-45 covers 10kHz to 1000MHz in a single unit, which spans both the conducted immunity range and the radiated immunity band to 1GHz. Above 1GHz you will need an RFA 1060 alongside it.
Whether a single unit is sufficient depends on the levels required, since a broadband amplifier trades power for coverage. Where higher levels are needed at either end, a pair of narrower amplifiers will usually be the better answer.
Both are push-pull MOSFET Class A platforms aimed at conducted immunity. The RFA 230 covers 150kHz to 230MHz at 22W to 80W in a 3U case, and is the more economical choice where the commercial standard is the requirement.
The RFA 250 extends the low frequency limit down to 10kHz, raises the top end to 250MHz, and offers 80W to 400W in a 4U case. Choose it where automotive or military limits apply, or where the test level demands more power.
Request a Quote
RFA amplifiers are available individually or as part of a configured immunity test system, bundled with the test cells, antennas and coupling devices that match your requirements. Tell us the standard you are testing to, the level you need to reach and what you are driving, and we will size and quote the right system.