Indoor antenna far-field measurement system is an automatic measurement system which is based on intelligent instrument and PC (or Industrial Computer), with the ability of data collection, analysis and processing. Test system takes main monitoring computer as the core, and automatically completes antenna far-field measurement task, by conducting and controlling the same functional peripheral equipments, such as vector network analyzer,receiver positioner, polarization positioner and etc.

Main monitoring computer transmits control signals into positioner's controller via RS-232 interface, to control antenna polarization match and direction axis rotation through connector; meanwhile, it controls vector network analyzer (which meets amplitude & phase test requirements of antenna, and has computer programming control function) via IEEE-488, and collects the amplitude signal of tested antenna. The test software can also analyze the radiation characteristic parameters of antenna far field, obtaining a series of parameters, such as antenna gain, Front-Back Ratio, half-power point beamwidth, zero position, each sidelobe width, each sidelobe location and related level value.

Meanwhile, the above parameters can be displayed on CRT or output through the printer. Since the system software adopts modular structure, operators just need to type the required parameters according to menu prompt, and then it will start automatic measurement, analysis and calculation, and get a high-precision result quickly.

In the diagram: 1 - antenna bracket , 2 - 2D positioner , 3 - polarizationpositioner , 4 - positioner's controller , 5 - Main monitoring computer , 6 - test software , 7 - positioner's control cables , 8 - RF cables , 9 - source antenna ,10 - tested antenna , 11 - vector network analyzer , 12 - printer , 13 - microwave anechoic chamber