A calibration system comprises an actuator circuit comprising a first delay circuit that receives a plurality of data pulses and a second delay circuit that receives the pulses, wherein one of the first and second delay circuits delays the data pulses independently of the other of the first and second delay circuits; a data switch that receives an output of the actuator circuit including delay data signals of the data pulses from the first and second delay circuits and switches and outputs a plurality of local oscillator (LO) signals for output as a controlled LO signal according to control signals of the delay data signals and applied to the data switch. At least one calibration switch receives the output of the actuator circuit and the plurality of LO+ and LO− signals, and outputs a second controlled LO signal output to a sense circuit.

A resonant power feeding system that can provide high power transmission efficiency between a power feeding device and a power reception device without dynamically controlling the oscillation frequency in accordance with the distance between the power feeding device and the power reception device. High power transmission efficiency between the power feeding device and the power reception device is obtained by addition of a structure for adjusting the matching condition to both the power reception device and the power feeding device. Specifically, a transmission-reception circuit and a matching circuit are provided in both the power reception device and the power feeding device, and wireless signals for adjusting the matching circuit are transmitted and received through a resonant coil. Thus, the power feeding device can efficiently supply power to the power reception device without adjusting the oscillation frequency.

A resonant power feeding system that can provide high power transmission efficiency between a power feeding device and a power reception device without dynamically controlling the oscillation frequency in accordance with the distance between the power feeding device and the power reception device. High power transmission efficiency between the power feeding device and the power reception device is obtained by addition of a structure for adjusting the matching condition to both the power reception device and the power feeding device. Specifically, a transmission-reception circuit and a matching circuit are provided in both the power reception device and the power feeding device, and wireless signals for adjusting the matching circuit are transmitted and received through a resonant coil. Thus, the power feeding device can efficiently supply power to the power reception device without adjusting the oscillation frequency.

A terahertz wave fast modulator based on coplanar waveguide combining with transistor is disclosed. The terahertz waves are inputted through a straight waveguide structure, and then are coupled through a probe structure onto a core part of the present invention, which includes a suspended coplanar waveguide structure and a modulation unit with high electron mobility transistor, wherein the suspended coplanar waveguide structure is formed by three metal wires and a semiconductor substrate; and the modulation unit with high electron mobility transistor is located between adjacent metal transmission strips of the coplanar waveguide structure. Transmission characteristics of the terahertz waves in the coplanar waveguide structure are changed through the switching on/off of the modulation unit, so as to fast modulate the amplitudes and phases of the terahertz waves, and finally the modulated terahertz waves are transmitted through a probe—waveguide structure.

A terahertz wave fast modulator based on coplanar waveguide combining with transistor is disclosed. The terahertz waves are inputted through a straight waveguide structure, and then are coupled through a probe structure onto a core part of the present invention, which includes a suspended coplanar waveguide structure and a modulation unit with high electron mobility transistor, wherein the suspended coplanar waveguide structure is formed by three metal wires and a semiconductor substrate; and the modulation unit with high electron mobility transistor is located between adjacent metal transmission strips of the coplanar waveguide structure. Transmission characteristics of the terahertz waves in the coplanar waveguide structure are changed through the switching on/off of the modulation unit, so as to fast modulate the amplitudes and phases of the terahertz waves, and finally the modulated terahertz waves are transmitted through a probe—waveguide structure.

A modulation circuit includes a load and a transistor serving as a switch. The transistor has an oxide semiconductor layer in which hydrogen concentration is 5×10.sup.19/cm.sup.3 or less. The off-state current of the transistor is 1×10.sup.−13 A or less. A modulation circuit includes a load, a transistor serving as a switch, and a diode. The load, the transistor, and the diode are connected in series between the terminals of an antenna. The transistor has an oxide semiconductor layer in which hydrogen concentration is 5×10.sup.19/cm.sup.3 or less. An off-state current of the transistor is 1×10.sup.−13 A or less. On/off of the transistor is controlled in accordance with a signal inputted to a gate of the transistor. The load is a resistor, a capacitor, or a combination of a resistor and a capacitor.

A modulation circuit includes a load and a transistor serving as a switch. The transistor has an oxide semiconductor layer in which hydrogen concentration is 5×10.sup.19/cm.sup.3 or less. The off-state current of the transistor is 1×10.sup.−13 A or less. A modulation circuit includes a load, a transistor serving as a switch, and a diode. The load, the transistor, and the diode are connected in series between the terminals of an antenna. The transistor has an oxide semiconductor layer in which hydrogen concentration is 5×10.sup.19/cm.sup.3 or less. An off-state current of the transistor is 1×10.sup.−13 A or less. On/off of the transistor is controlled in accordance with a signal inputted to a gate of the transistor. The load is a resistor, a capacitor, or a combination of a resistor and a capacitor.

A phase and/or amplitude modulation device includes a TORP signal generator and, during a phase modulation or a phase and amplitude modulation, a generator of a phase-modulated periodic signal of frequency F.sub.PRP applied to a control input of the power supply circuit of the TORP signal generator. The device may also include, during an amplitude modulation or a phase and amplitude modulation, 2.sup.P TORP generators, a thermometric code generator on 2.sup.P bits coding an amplitude modulation, a TORP generator control circuit, applying or not, to the control input of the TORP generator power supply, the periodic signal of frequency F.sub.PRP depending on the bits of the thermometric code signal, and a processing circuit coupled to the outputs of the TORP generators, and configured to produce a linear combination of signals outputted by the TORP generators.

An example apparatus includes: an on-off keying (OOK) modulator including: a first transistor including a first control terminal; a second transistor including a first current terminal, a second current terminal, and a second control terminal, the first current terminal coupled to the first control terminal; a third transistor including a third current terminal, a fourth current terminal, and a third control terminal, the third current terminal coupled to the first control terminal; a fourth transistor including a fifth current terminal, the fifth current terminal coupled to the second current terminal; and a fifth transistor including a sixth current terminal, the sixth current terminal coupled to the fourth current terminal.

An oscillator circuit includes a total of N (N≥2) class-D oscillator circuits stacked together between a supply voltage node and a reference voltage node. The output ports of adjacent class-D oscillator circuits in the disclosed oscillator circuit are coupled together by capacitors to ensure frequency and phase synchronization for the frequency signals generated by the class-D oscillator circuits. Compared with a reference oscillator circuit formed of a single class-D oscillator circuit, the oscillation amplitude of each of the class-D oscillator circuits in the disclosed oscillator circuit is 1/N of that of the reference oscillator circuit, and the current consumption of the disclosed oscillator circuit is 1/N of that of the reference oscillator circuit.