The modulation includes in amplifying the microwave signal phase shifted by a given angle into a first sinusoidal signal, in order to obtain a first amplified signal; and in amplifying the microwave signal phase shifted by the given angle increased by into a second sinusoidal signal phase shifted by with respect to the first signal, in order to obtain a second amplified signal phase shifted by with respect to the first amplified signal; the modulated microwave signal being the sum of the first amplified signal and the second amplified signal.

A modulator may include a controller configured to receive in-phase (I) baseband signals and quadrature-phase (Q) baseband signals. The controller may be configured to select a section of a region defined by a number of local oscillator (LO) phases. The controller may be configured to output multiple control signals and a pair of phase selection signals. The modulator may further include multiple output stages. Each output stage may be coupled to the controller to receive a pair of the control signals, the pair of phase selection signals, and multiple offset LO signals. Each of the output stages may include a unit element.

A method of wireless communication includes transmitting frames from a transponder to a reader and synchronizing between a reader carrier frequency and an active load modulation (ALM) carrier frequency within each transmitted frame. Each transmitted frame includes ALM carrier bursts generated from subcarrier modulation by binary phase shift keying (BPSK) data encoding and producing signal oscillations at a transponder antenna after each ALM carrier burst generation, The synchronizing occurs at each phase change of the data encoding when no burst is generated during a half period of the subcarrier preceding the phase change and a half period of the subcarrier following this phase change. The transponder antenna has a moderate quality factor sufficient to naturally damp the signal oscillations so that the synchronizing is performed without performing any controlled signal oscillations damping.

A modulator may include a controller configured to receive in-phase (I) baseband signals and quadrature-phase (Q) baseband signals. The controller may be configured to select a section of a region defined by a number of local oscillator (LO) phases. The controller may be configured to output multiple control signals and a pair of phase selection signals. The modulator may further include multiple output stages. Each output stage may be coupled to the controller to receive a pair of the control signals, the pair of phase selection signals, and multiple offset LO signals. Each of the output stages may include a unit element.

A circuit includes a polar transmitter to generate a radio frequency output from amplitude and phase signal components. The polar transmitter includes an amplifier to combine amplitude and phase signal components. A processor is coupled to the polar transmitter to provide the amplitude and phase signal components. The processor includes: a digital modulation circuit to generate a modulated digital signal including in-phase and quadrature signal components and a correction circuit to calculate and apply a complex digital offset for local oscillator feedthrough of the amplifier. The complex digital offset includes an in-phase offset correction factor and a quadrature offset correction factor.

A signal generator generates an electrical signal that is sent to an amplifier, which increases the power of the signal using power from a power source. The amplified signal is fed to a sender transducer to generate ultrasonic waves that can be focused and sent to a receiver. The receiver transducer converts the ultrasonic waves back into electrical energy and stores it in an energy storage device, such as a battery, or uses the electrical energy to power a device. In this way, a device can be remotely charged or powered without having to be tethered to an electrical outlet.

A signal generator generates an electrical signal that is sent to an amplifier, which increases the power of the signal using power from a power source. The amplified signal is fed to a sender transducer to generate ultrasonic waves that can be focused and sent to a receiver. The receiver transducer converts the ultrasonic waves back into electrical energy and stores it in an energy storage device, such as a battery, or uses the electrical energy to power a device. In this way, a device can be remotely charged or powered without having to be tethered to an electrical outlet.

A transmission system includes a first transponder including a first I/Q modulator, and a second transponder including a second I/Q modulator, and configured to communicate with the first transponder using a frequency modulation scheme, wherein the first transponder is configured to set a first phase rotation mode in a first state for first light signal output from the first I/Q modulator, and transmit, to the second transponder, a first command to specify a second phase rotation mode for second light signal output from the second I/Q modulator, and the second transponder is configured to set, in response to the first command, the second phase rotation mode in a state specified by the first command.

A transmission system includes a first transponder including a first I/Q modulator, and a second transponder including a second I/Q modulator, and configured to communicate with the first transponder using a frequency modulation scheme, wherein the first transponder is configured to set a first phase rotation mode in a first state for first light signal output from the first I/Q modulator, and transmit, to the second transponder, a first command to specify a second phase rotation mode for second light signal output from the second I/Q modulator, and the second transponder is configured to set, in response to the first command, the second phase rotation mode in a state specified by the first command.

A system and method are provided relating generally to data transmission and more particularly to modulation techniques offering increased data transmission rates. To so provide, a first amplitude-time modulated (ATM) signal and a first phase modulated signal are combined at a first combiner to produce a complex wave modulation signal, and the complex wave modulation signal and an additional signal are combined at a second combiner to produce a second complex wave modulation signal. The additional signal may be a second ATM signal or a second phase modulated signal. Optionally, the second complex wave modulation signal and a second additional signal may be combined to produce a third complex wave modulation signal. In accordance with at least one embodiment, a shape of an element of information according to the first ATM signal may be defined programmatically over subportions of less than the duration of the element of information.