A 4 × 4 Butler matrix (BM) optimized for UMTS applications is presented. Special care is taken for the design of the elliptic couplers and the line crossovers. The BM is fabricated by conventional photolithography on a single laminate. No expensive double layer/multi-layer or high permittivity substrates or high-temperature superconductors are used. The design is compact and complies with the bandwidth specifications of the UMTS band.
|Number of pages||4|
|Journal||Microwave and Optical Technology Letters|
|Publication status||Published - Mar 2007|
- Butler matrix
- Directional coupler
- Lange coupler
- Smart antennas