The controller is a standard PC with operating system Microsoft® Windows. Depending on the system layout GPIB (IEEE488) with National Instruments interface card, serial bus RS232, USB and other bus systems are supported.
CR-LAB is fully compliant to IEC/EN 61000-4-3, IEC/EN 61000-4-20, automotive and MIL standards. The software CR-LAB controls the complete test system and creates the test report. It performs measurement of the uniform area and generates reference calibration data from it. Alternatively reference data can be measured directly. Tests may be performed manually and fully automatic. A full automatic monitoring of the EUT´s (Equipment Under Test) function is possible whenever its compliance can be controlled with preset tolerance limits. Up to four values can be monitored and recorded for example by means of multimeters.
As signal source a commercial signal generator or the built-in signal generator of our EMC test & control unit ECU-3/-6 is used. It should cover at least the required frequency range such as 80 MHz to 6 GHz and allow amplitude modulation with a sine wave of 1 kHz and 80 %, as requested by the standards. Besides, it should meet the requirements regarding frequency step width (1 % of the preceding value). If the equipment offers further modulation depth and modes, as well as a higher frequency range and smaller steps, this might be advantageous for future applications.
The software controls the level of the signal generator output for each test frequency. This signal level is amplified by the power amplifier output in order to generate the required test field strength around the EUT. It depends on the testing setup, the distance between EUT and antenna (1 m - 3 m) and the test level / test field strength (1 V/m, 3 V/m, 10 V/m or special requirements) whether an amplifier output of 10 W, 30 W, 200 W - 2 kW is required. Normally, field strength of 10 V/m, with 1 kHz / 80% AM, can be obtained with a 200 W amplifier in a testing distance of 3 m.
While testing the field strength probe is replaced by the EUT. A power measurement during the test runs assures that the EUT is actually exposed to the requested test condition. Thus a directional coupler is connected with the amplifier output. A power measuring device type PMS 1084 determines the forward and reverse power up to 6 GHz. Both are stored and recorded by the control software. For this purpose directional couplers are connected with the amplifier output or the built-in directional couplers of our EMC test & control unit ECU-3/-6 is used. The forward and reverse power is measured by our RF-Power Meter PMS 1084 or by the built-in power measuring channels of the ECU-3/-6. Both metering values are recorded and stored by the control software CR-LAB.
Broadband antennas, like our model AXL-4000, which cover the whole frequency range from 80 MHz up to 4 GHz may be used as a single-antenna-solution. The advantage of these antennas is that they can be used for immunity tests as well as for emission measurements. In order to save amplifier power and costs it is recommended to use so called double stacked log.-periodical antennas for immunity tests, like our model AXL-80. This antenna type offers a much higher gain compared to the above described broadband antennas.