INEXPENSIVE MODE FORMATION CIRCUIT HAVING EVEN NUMBER OF PORTS

摘要

PROBLEM TO BE SOLVED: To obtain a mode formation circuit which can be used together with N port antennas for an arbitrary even number N. SOLUTION: A mode formation circuit 100 includes a first matrix circuit 102 provided with a network which realize at least one N/2×N/2 identity matrix and at least one N/2×N/2 phase shifting matrix and through which transmission lines 208-212 and phase shifters 216-218 are interconnected. The first matrix circuit 102 is connected in series with a second matrix circuit 104. The second matrix circuit 104 comprises a network which realizes at least on N/2×N/2 phase shifting matrix and through which phase shifters are connected to each other.