Communication apparatus and phase adjustment method

A phase adjustment method for use in a communication apparatus comprising a plurality of communication devices each of which transmits or receives a signal and each of which includes a phase adjuster for adjusting the phase of the signal, and an oscillator which supplies a first signal with a first frequency, the method comprising:

• by a switching device, modulating at least one of the first signal passed through a first communication device among the plurality of communication devices and a second signal with the first frequency but not passed through the first communication device at a second frequency lower than the first frequency;
• by a signal combiner, combining together the first signal passed through the first communication device and the second signal, at least one of which is modulated, to generate a composite signal containing a switching frequency component with an amplitude in response to a phase difference taken between the first signal and the second signal at the second frequency;
• based on the switching frequency component contained in the composite signal, obtaining as a reference phase adjustment amount a phase adjustment amount applied by the phase adjuster in the first communication device when the phase difference between the first signal and the second signal is at a prescribed value;
• and
• based on the reference phase adjustment amount, controlling the phase adjuster in the first communication device so that a predetermined phase difference is provided between the signal that the first communication device transmits or receives and the signal that a second communication device adjacent to the first communication device among the plurality of communication devices transmits or receives.

A communication apparatus comprising:

• a plurality of transmitters each of which transmits a signal and each of which includes a phase adjuster for adjusting the phase of the signal;
• an oscillator which supplies to each of the plurality of transmitters a first signal obtained by modulating a signal with a first frequency at a second frequency lower than the first frequency;
• a signal combiner which is disposed at a position at which a difference between a signal line length from a first communication device among the plurality of communication devices and a signal line length from a second communication device adjacent to the first communication device among the plurality of communication devices is equal to an integral multiple of a wavelength corresponding to the first frequency, and which combines together the first signal output from the first communication device and the first signal output from the second communication device to generate a composite signal containing a switching frequency component with an amplitude in response to a phase difference taken between the first signal output from the first communication device and the first signal output from the second communication device at the second frequency;
• and
• a controller which, based on the switching frequency component contained in the composite signal, obtains as a reference phase adjustment amount a phase adjustment amount applied by the phase adjuster in the first communication device when the phase difference between the first signal output from the first communication device and the first signal output from the second communication device is at a prescribed value, and which, based on the reference phase adjustment amount, controls the phase adjuster in the first communication device so that a predetermined phase difference is provided between the first signal that the first communication device outputs and the first signal that the second communication outputs.