Design of a 60 GHz Series-Fed Patch Array and Full-Wave Evaluation of Its Sparse-Layout Extension for Indoor Short-Range Communication

A 60 GHz antenna array with enhanced radiation performance is investigated for indoor short-range communication applications. To improve array gain while maintaining a fixed number of equivalent elements, an optimized sparse-layout extension approach based on equivalent series-fed subarrays is proposed. An E-shaped microstrip patch and a 1 × 10 Chebyshev-tapered series-fed subarray are first designed, followed by the development of a 4 × 10 baseline planar array. Measurements demonstrate a −10 dB impedance bandwidth of 57.13–62.36 GHz, while the reconstructed radiation patterns indicate a peak realized gain of 17.23 dBi at 60 GHz. The 1 × 10 subarray is then treated as an equivalent element to establish 10-element compact uniform, equal-aperture uniform, and optimized sparse arrays. The equivalent-element positions are optimized using an ideal-array model implemented in MATLAB R2024a and subsequently mapped onto HFSS full-wave models for electromagnetic evaluation. Compared with the equal-aperture uniform array, the optimized sparse array increases the peak realized gain in the Φ = 90° plane from 22.57 to 23.94 dBi and reduces the maximum interport coupling from −12.31 to −26.33 dB while preserving a stable main-beam direction. The MATLAB–HFSS comparison shows similar beamwidths; analyses at 58, 60, and 62 GHz reveal frequency-dependent sidelobe and beam-pointing variations and assess excitation-error sensitivity.