Radio communication apparatus, transmitter, and radio communication method

A transmitter comprising:

• a plurality of antennas;
• local signal phase shifters each setting a phase of local signal to a controlled value;
• baseband signal phase shifters each setting a phase of a baseband signal to a controlled value;
• quadrature modulators each up-converting the baseband signal output from a corresponding one of the baseband signal phase shifters by the local signal from a corresponding one of the local signal phase shifters and converting frequency of the baseband signal to generate a transmission signal;
• 180° distributors each distributing the local signal into two signals of 0° and 180°, in place of the local signal phase shifters each setting the phase of the local signal to a controlled value;
• and
• a mechanism for controlling a radiation direction of a radiation signal to be sent from each of the antennas,
• wherein first radiation direction of the transmission signal to be sent from each of the antennas and second radiation direction of a local leak signal can be controlled independently from each other,
• the number of the baseband signal phase shifters, and the number of the quadrature modulators are all equal to each other and the number of plurality of antennas, and
• the number of the plurality of antennas is an odd number (2n+1) (n is an integer), and the transmitter comprises n pieces of the 180° distributors and one local phase shifter which sets the phase of the local signal to a controlled value.

A radio communication method comprising

• when a radiation direction of a radio signal to be sent from each of a plurality of antennas is controlled,
• setting, by local signal phase shifters, a phase of local signal to a controlled value;
• setting, by baseband signal phase shifters, a phase of a baseband signal to a controlled value;
• up-converting, by quadrature modulators, the baseband signal by the local signal and converting frequency of the baseband signal to generate a transmission signal;
• distributing, by each of 180° distributors, the local signal into two signals of 0° and 180°, in place of the local signal phase shifters each setting the phase of the local signal to a controlled value, and
• controlling first radiation direction of the transmission signal to be sent from each of the plurality of antennas and second radiation direction of a local leak signal independently from each other
• the number of the baseband signal phase shifters, and the number of the quadrature modulators are all equal to each other and the number of plurality of antennas, and
• the number of the plurality of antennas is an odd number (2n+1) (n is an integer), and n pieces of the 180° distributors and one local signal phase shifter sets the phase of the local signal to a controlled value.