DUCAT

The Delft University Chamber for Antenna Tests (DUCAT) is a moderate size anechoic chamber which allows for far-field and near-field measurements thanks to a foldable inverted T scanner. It has recently been refurbished with new absorbers and stepping motors.

Inside of the DUCAT (near-field configuration)

Far-field mesurements configuration of the DUCAT

Chamber description

The chamber is a 6m x 3m x 3m Faraday cage providing 120 dB isolation ( at 10 GHz ) to reject external interferences. The walls, ceiling and floor are covered with RF absorbers with reflectivity performance below -40 dB from 1.2 GHz to 40 GHz. The maximum distance between the transmitting antenna and the antenna under test is 4 meters, meaning that a 10 cm aperture antenna is still in the far-field zone at 60 GHz.

Mechanical subsystem

The mechanical subsystem consists of 9 stepping motors.

The antenna under test (AUT) positioner is a roll over azimuth type, mounted on a dual axis translation stage to allow for accurate alignment of the AUT's phase centre with the rotation axis. The azimuthal resolution is better than 0.001 degrees.

The transmit antenna can be aligned in azimuth and elevation.

The foldable inverted T planar scanner has a 2m x 2m aperture. The resolution is better than 10um.

Configurations

Far-field

Planar near-field

Cylindrical near-field

Plane-polar near-field

RF subsystem

A 4-port vector network analyser is used as RF source and receiver for the antenna measurement set-up. The N5227A covers the frequency range from 10 MHz to 67 GHz with a dynamic range better than 120 dB thanks to the direct receiver access option which bypasses the internal directional coupler.

In addition a 24-port test-set can be used up to 20 GHz.

Dedicated phase-stable flexible RF cables are used with manufacturer specifications up to 50 GHz.

An object in scanner of the DUCAT

Near-field probes and standard gain horns

Our research group owns an array of near-field probes covering the frequencies from 1 GHz to 26 GHz. For far-field measurements standard gain horns are used which cover all bands from L to W (1 GHz to 110 GHz).

Additional Measurement Equipment

Following list of equipment is available for the MS3 group and can be used for measurements within DUCAT.

*Equipment*	*Frequency band*
Network Analysers:
Agilent HP 8753D	30 KHz - 6 GHz
Agilent E 8364B	10 MHz - 50 GHz
Agilent N5242A (4 ports)	10 MHz - 26.5 GHz
Agilent N5227A (4 ports)	10 MHz - 67 GHz
Millimeter wave extension modules:
Agilent N5260-60003	67 GHz - 110 GHz
Multiport test set
Agilent 87050A - K24 (24 ports)	10 MHz - 20 GHz
Spectrum Analysers
Agilent 8592A	50 KHz - 22 GHz
Agilent 8565E	9 KHz - 50 GHz
Arbitrary Waveform generator
Tektronix AWG 5014B	1.2 GS/s
Oscilloscopes
Tektronix 784A	1 GHz, 4 GS/s
Agilent DSO-X-91604A	16 GHz, 40/80GS/s
Geozondas SD3003NF + SU4126NF	100 MHz - 26 GHz (stroboscopic 10 MHz)
Power meters
Anritsu ML2437A	up to 50 GHz
Agilent E4418A	up to 110 GHz