研究目的
To propose and implement a new dual band 4 × 4 butler matrix without crossover and a new dual band 45° phase shifter for applications in satellite communication systems, mobile communication systems, and wireless local area networks.
研究成果
The proposed dual band 4 × 4 butler matrix without a crossover and the new dual band 45° phase shifter have been successfully designed and implemented. The design is simpler and capable of performing dual band operations beyond the 2.7 band ratio. The measured and simulated results validated the design methodology, showing good agreement.
研究不足
The dual band coupler, phase shifter, and BM can be fabricated only when the band ratio between the operating frequencies is 2.0 to 2.9, 2.3 to 2.9, and 2.3 to 2.9, respectively.