Breakthrough methodology accelerates large-scale active antenna calibration and testing

September 11, 2012 // By Jean-Pierre Joosting
Agilent Technologies claims to offer the industry’s widest-bandwidth real-time digital downconverter (DDC) option on the M9703A AXIe eight-channel high-speed digitizer. This DDC functionality enables faster, more flexible measurements in high-channel-count applications.

In many multi-antenna applications such as radar, direction-finding and satellite beam-forming, phase-coherent acquisition channels are critical for accurate data acquisition, whether for antenna calibration or channel sounding. Traditional test platforms are generally limited to measurements involving sinusoids, which preclude testing with broader band signals, such as multitone or live signals.

For such complex signals, the exclusive real-time processing algorithm of the company’s latest DDC functionality enables phase-coherent measurements across eight input channels.

With a frequency range of DC to 2 GHz and a sampling rate of 1.6 GS/s, the M9703A-DDC digitizer option provides tuning and zooming capabilities to analyze these signals of interest. The DDC programmable decimation ratio and fine IF tuning allow users to set the bandwidth and center frequency to match the analyzed signal. Real-time decimation allows users to analyze bandwidth from 300 MHz down to less than 1 kHz, reduces the noise level, improves the dynamic range by 3 dB per decimation step, and extends the capture time.

For advanced measurement analysis, the M9703A AXIe high-speed digitizer is compatible with the company’s 89600 Vector Signal Analysis software, the industry’s standard for signal analysis and demodulation.

The M9703A AXIe digitizer, combined with an Agilent two-slot or five-slot AXIe chassis, allows users to easily scale up the number of parallel acquisition channels without the use of switches, reaching up to 40 channels in only 4U of rack-mount space using five digitizers. This enables simultaneous acquisition of data on a large number of channels under dynamic conditions, reducing test and calibration time by days and even weeks, while improving overall test efficiency and cutting costs.

The M9703A digitizer with the DDC option is also useful in electronic warfare and MIMO applications that need simultaneous wide-bandwidth and high dynamic-range measurements on multiple channels.

A video showing the advantages of the M9703A-DDC for phased-array antenna testing can be viewed at