Monopulse array and low side-lobe level array with a novel feed network

This study presents the methodology design and implementation of a novel feed network. This feed network consists of several ring couplers with miniaturised and wideband characteristics. The size of this coupler is significantly reduced by employing /6 sections and open stubs. Besides, wideband performance is achieved by introducing a phase inverter. Compared to traditional ring couplers, the size of the proposed coupler is reduced by nearly 90%, and the relative bandwidth (BW) of the demonstrated ring coupler can reach about 80%. Owing to the miniaturised size and wideband characteristics of this ring coupler, this kind of feed network is much smaller than traditional ones with similar BW. On the basis of this feed network, a monopulse array and a low side-lobe level array is designed and fabricated. Good agreements are achieved between simulations and measurements.