Improved Two-Antenna Direction Finding Inspired by Human Ears

 Microwave passive direction finding is a very important technology that has many military and commercial applications including electronic warefare, mobile communications, etc. A typical microwave direction finding system may use an array consists of a large number of antenna elemants and sophisticated algorithms to achieve high degree of accuracy. However, the size, weight, speed and cost associated with the large number of hardware components and the complicated signal processing can be impractical, especially for portable and commercial applications. In addition, accurate and efficient direction finding will be very useful in next generation wireless systems for location based services and applications.

 We propose a novel direction of arrival (DOA) estimation technique using only two antennas, which is inspired by the human auditory system. By incorporating a head-like scatter between two monopole antennas, both phase and magnitude information can be utilized to estimate the DOA of a microwave signal, thus eliminating ambiguities associated with phase wrapping at high frequency. In addition, better DOA sensitivity is demonstrade with the incororaion of the head-like scatter. Both numerical modeling and experimental results of a simple X-band two-monopole configuration with symmetric and asymmetric scatters are presented. The asymmetric configuration is realized by shifting the scatter to one side of the antennas.


The passive microwave direction finding system and the human auditory system

A photograph of the two-monopole and symmetric scatter prototype

Simulated averaged DOA estimation errors