US Patent 9954265 Two-transmitter two-receiver antenna coupling unit for microwave digital radios

An antenna coupling device is disclosed. The device includes a first isolator that includes an input port and an output port and a first circulator that includes a first port, a second port, and a third port. The first port of the first circulator is coupled with the output port of the first isolator; and the second port of the first circulator is configured for coupling with a first antenna. The device also includes a second isolator that includes an input port and an output port. The input port of the second isolator is coupled with the third port of the first circulator.