Near field probes are an essential part of any EMC toolkit. They help to locate the source of any emissions, and to view the frequency components being emitted, without the potential confusion of ambient signals.

LETIS

LETIS (Laplace EMC Test Integration System)

Power amplifiers that are universally used for radiated immunity testing either cover the range below 1GHz or the range above 1GHz. This means that if the test requirement extends both sides of this 1GHz point, the power amplifier needs to be changed over. Genrally, this involves three connections

• the RF signal from the synthesiser to the PA
• the RF output from the PA to the antenna/cell
• Interlock/standby connections

The LETIS handles all these connections automatically. Each is switched via a high performance RF relay under the control of a USB interface. Software issued with the Laplace Synthesisers automatically detects the presence of a LETIS and handles the switching automatically.

• Switch power amplifiers at the appropriate frequency
• Automatic operation
• Avoid mis-connections
• Avoid wear and tear on connectors
• Faster testing, better productivity

LETIS is an optional extra for the following products:
Test cells (LaplaCell)
RF Synthesiser

SA1020A

Pre Amplifier

The SA1020 is a Broadband RF amplifier with 20dB gain. As it it is designed to have a 50 ohm impedance it can be used together with any probe or antenna / analyzer combination. Its key features are exceptionally low noise, flat gain characteristics and wide frequency range.

• Low noise
• High gain
• self contained
• Calibrated

For more pre amplifier options, with higher frequency ranges, please also check our range of Teseq pre amplifiers

RF100

Near Field Probe Set

The RF100 probe set consists of a passive E field probe and H field probe, BNC adaptor and carry case. The output is via a BNC socket. These are general purpose probes which are ideal for use in conjunction with an EMC measuring system. They are sensitive to sources in close proximity, but are insensitive to background signals. This makes them ideal for the identification of emission frequencies in noisy environments... thus making measurements easier and quicker. The proximity requirement also enables sources to be located and the exit route identified.

For greater sensitivity, the probes can be used in conjunction with the SA1020 pre-amplifier. A BNC-BNC adaptor (included with the kit) enables direct connection to the pre-amp.

• Essential accessory for EMC testing and product evaluation
• E and H field probes included
• Works with any analyser or receiver
• Identify emission sources
• Identify potential problem frequencies
• Perfect 'sniffer probes'

RF 600

RF 600 filter

FM radio band filter (85MHz - 108MHz)

Key Points

• Stop band attenuation 35dB
• Fits between antenna and analyser
• Low insertion loss at all other frequencies

RF 700

RF 700 filter

30 MHz high pass filter

Key Points

• Reduces possibility of compression, improves measurement accuracy
• Very effective at removing the high levels of noise often present below 30MHz
  (especially in industrial areas)
• Fits between antenna and analyser

RF 800

RF 800 filter

Bandpass filter for conducted emission testing (150 kHz - 30 MHz)

Key Points

• Simple form of pre-selection
• Effectively improves your dynamic range
• Low insertion loss at all other frequencies

Field Probes

Field Probes

A wide range of meters and probes cover a range of applications from Mobile to Fixed, environmental to laboratory testing. The FieldMeters include output sockets for connection to data loggers or monitoring equipment.

Options include fibre optic and RS232 interfaces, with PC software supplied. All FieldMeters are supplied with manufacturers calibration certificate. Optionally, each meter can be supplied with a NIST traceable calibration covering accuracy and isotropicity. These meters have also been certified by NPL (UK).

Being compact and convenient battery powered, and with sturdy carry case, these meters are perfect for use in the field.

ERS

Emission Reference Source

The ERS is a comb generator that radiates RF continuously every 2MHz over the range 30MHz - 1000MHz. Each 2MHz peak is precisely measured during the calibration process with the ERS orientated both vertically and horizontally. These measurements are correlated against a 3m OATS such that any fully implemented CISPR16 site, measuring at 3m and using height scanning, will read the same. In practice, informal sites and test chambers will produce significant differences due to the presence of reflections and/or lack of height scanning. The ERS allows these differences to be quantified and EUT measurements can then be corrected.

This technique substantially improves the measurement accuracy of radiated emissions on all but the best test sites.

• Very stable and accurate
• 30MHz - 1GHz coverage
• Traceable to NPL (UK)
• Narrowband peak every 2MHz
• Horizontal and vertical calibration

The ERS helps to eliminate the main cause of uncertainty (error) when measuring radiated emissions. These errors are entirely due to the reflections from any nearby metallic objects or surfaces. Also, the ground reflection is a source of error if not using a metallic ground plane and height scanning. Generally, these reflections will account for errors up to 20dB, far too much for compliance measurements.

By replacing the EUT with the ERS, performing a scan and comparing the results with the calibration data, the errors can be quantified and the results from the EUT adjusted accordingly. This technique genarally reduces errors to around 6dB, comparable with test laboratory results.