Two-Way Pattern Design for Distributed Subarray Antennas

• Main Author: Cher, Hock Hin
• Other Authors: Jenn, David C.
• Published: Monterey, California. Naval Postgraduate School 2012
• Online Access: http://hdl.handle.net/10945/17341

Approved for public release; distribution is unlimited === Modern phased array radar uses multifunction subarray antennas in a distributed fashion. Distributed subarrays (DSA) have the advantages of more efficient scheduling of track and search functions, rapid steering capability, decreased complexity in digital beamforming and better angular resolution. However, one disadvantage of the DSA are the extra grating lobes due to large subarray spacing which can cause ambiguities in angle measurements and excess background clutter. A possible approach to suppress the grating lobes is to design separate transmit and receive subarray antennas that have different radiation patterns. The purpose of this research was to develop a program based on the principle of pattern multiplication to synthesize and access the two-way antenna pattern for DSAs. The program, written in MATLAB, allows the user to study the two-way antenna pattern for different subarray architectures. The program was able to synthesize the pattern for isotropic elements, short dipoles and half-wave dipoles in a planar array above a ground plane. A simulation tool was also developed to map the grating lobe and null locations of the antenna patterns in direction cosine space. Several DSA configurations were examined, and the results showed that undesired grating lobes can be suppressed by subarray nulls.