Design Of IF Signal Processing And Control Module For Dual Channel Antenna Measurement System

With the rapid development of antennas theory, antenna measurement technology has become an important part of the antenna design. Dual channel antenna measurement system is a near-field antenna measurement system, it calculates the various parameters of the antenna by comparing the amplitude and phase value between the reference channel and test channel signal. An instrument which has full automatic, high precision, fast measurement work for antenna measurement system can greatly reduce the system measuring time.In this thesis, an IF(intermediate frequency) signal processing module which has a function of amplitude and phase measurement has been designed in FPGA hardware platform based on dual antenna measurement system. And a scheme for overall control antenna measurement which can improve the measurement efficiency has been designed according to the basic process and measurement system. Firstly, the thesis studied the traditional IF signal processing program, pointed out that the program had serious spectral leakage problem that cannot be applied to an actual antenna measurement, then put forward the all phase algorithm with the traditional approach of combining program, and verify the program for the spectral leakage with good inhibitory effect by principle analysis and algorithm simulation. The all phase of IQ quadrature demodulation algorithm has been implemented depending on the hardware of the logical framework of the algorithm. And the data storage solution based on DDR3_SDRAM has been designed due to the function of large capacity data cache. Finally through the study of antenna measurement system hardware modules, four kinds of sweep modes have been implemented that can be freely switching by parsing the PC command.The IF signal processing module designed in this thesis has improved the precision of the system because of the use of all phase algorithm. And the design of sweep mode has improved the measurement efficiency. According to the experiments on various functional modules, the feasibility of the scheme has been verified.And the performance indicators of the module have reached the expected.