A High-Precision and Low-Cost Planar Array Signal Simulator Based on Cable Delays

For common planar array in Global Navigation Satellite System (GNSS) receivers, effective array signal simulation requires high-precision control of time delays and is very sensitive to errors. Typical array time delay range is about 0 ~ 0.6 ns. The resolution and accuracy needed for time delay controlling is within 0.005 ns. Such rigorous specifications make array simulation quite difficult. Common techniques always need the collaboration of a large number of hardware equipments, which are costly and complicated and therefore limited to widespread applications. This letter presents a planar array signal simulator based on cable delays, which is less expensive, easy to implement, and high-precision. However, electromagnetic waves propagate at a relatively lower velocity in transmission lines than in air, which may result in large errors and problems in designing of the array wavefront simulator. In this letter, the velocity difference and its influence mechanism on array simulator design were analyzed deeply. On this basis, errors introduced by propagation velocity difference were calibrated, which effectively improved the accuracy of array signal simulators based on cable delays. Experimental results show that the direction-of-arrival (DOA) simulation accuracy is better than 5 °. The technique can be utilized in the research of adaptive antenna array anti-interference algorithm.