Digital beamforming for cellular technology applications

A beamforming device for a cellular radio frequency (RF) antenna apparatus, the device comprising:

• a first adjuster, to receive a first adjuster input signal indicative of a transmit (TX) signal in a first frequency band, and to generate a first adjuster output signal by modifying one or more of a phase and an amplitude of the first adjuster input signal;
• a second adjuster, to receive a second adjuster input signal indicative of a TX signal in a second frequency band, and to generate a second adjuster output signal by modifying one or more of a phase and an amplitude of the second adjuster input signal;
• a third adjuster, to receive the first adjuster input signal, and to generate a third adjuster output signal by modifying one or more of the phase and the amplitude of the first adjuster input signal, where the third adjuster output signal is different from the first adjuster output signal;
• a fourth adjuster, to receive the second adjuster input signal, and to generate a fourth adjuster output signal by modifying one or more of the phase and the amplitude of the second adjuster input signal, where the fourth adjuster output signal is different from the second adjuster output signal;
• a first combiner, to combine a signal indicative of the first adjuster output and a signal indicative of the second adjuster output into a first composite TX signal;
• and
• a second combiner, to combine a signal indicative of the third adjuster output and a signal indicative of the fourth adjuster output into a second composite TX signal.

A method of operating a beamforming device for a cellular radio frequency (RF) antenna apparatus, the method comprising:

• generating a first adjuster output signal by modifying one or more of a phase and an amplitude of a first adjuster input signal, where the first adjusted input signal is indicative of a transmit (TX) signal in a first frequency band;
• generating a second adjuster output signal by modifying one or more of a phase and an amplitude of a second adjuster input signal, where the second adjuster input signal is indicative of a TX signal in a second frequency band;
• performing digital upconversion to covert the first adjuster output to a first upconverted adjuster output;
• performing digital upconversion to covert the second adjuster output to a second upconverted adjuster output;
• and
• combining a signal indicative of the first adjuster output and a signal indicative of the second adjuster output into a composite TX signal,
• where an RF signal based on the composite TX signal is to be wirelessly transmitted by an antenna element.