Various embodiments of the present invention relate to an electronic device and a method for controlling transmission power, the electronic device comprising: an amplification circuit; an antenna electrically connected to the amplification circuit; a variable element capable of adjusting the impedance between the amplification circuit and the antenna; and a control circuit, wherein the control circuit can be configured to: output a signal, having been amplified by a designated gain by means of the amplification circuit, to an external electronic device by using the antenna, in a state in which the variable element is adjusted to a first impedance; detect the approach of an external object during outputting of the signal; in response to the detection of the approach of the external object, check control information by which the first impedance of the variable element can be changed to a second impedance; and adjust the designated gain on the basis of at least the control information.

Various embodiments of the present invention relate to an electronic device and a method for controlling transmission power, the electronic device comprising: an amplification circuit; an antenna electrically connected to the amplification circuit; a variable element capable of adjusting the impedance between the amplification circuit and the antenna; and a control circuit, wherein the control circuit can be configured to: output a signal, having been amplified by a designated gain by means of the amplification circuit, to an external electronic device by using the antenna, in a state in which the variable element is adjusted to a first impedance; detect the approach of an external object during outputting of the signal; in response to the detection of the approach of the external object, check control information by which the first impedance of the variable element can be changed to a second impedance; and adjust the designated gain on the basis of at least the control information.

Devices and/or computer-implemented methods to facilitate a Josephson traveling wave parametric amplifier (JTWPA) device with sideband suppression are provided. According to an embodiment, a device can comprise a plurality of unit cells including at least one Josephson junction and a shunt capacitor. The device can further comprise a plurality of first dispersion resonators coupled to the plurality of unit cells at a first interval. The plurality of first dispersion resonators suppress generation of at least one of a third order harmonic of a pump tone applied to the device, a third order intermodulation product, or a fifth order intermodulation product.

A bandpass parametric amplifier circuit includes a plurality of unit cells. At least one unit cell includes a first inductor having a first node coupled to a center conductor and a second node coupled to ground. There is a first capacitor having a first node coupled to the center conductor and a second node coupled to ground. There is a second inductor having a first node coupled to the center conductor. A second capacitor has a first node coupled to a second node of the second inductor. The second capacitor and the second inductor are in series with the center conductor.

According to an example aspect of the present invention, there is provided a travelling wave parametric amplifier comprising a waveguide transmission line comprising therein at least ten Josephson elements, wherein each of the at least ten Josephson element comprises a loop, with exactly one Josephson junction of first size on one half of the loop and at least two Josephson junctions of a second size on a second half of the loop, the second size being larger than the first size, a flux bias line configured to generate a magnetic flux threading each of the at least one loop, and a set of resistors coupled with the flux bias line.

According to an example aspect of the present invention, there is provided a travelling wave parametric amplifier comprising a waveguide transmission line comprising therein at least ten Josephson elements, wherein each of the at least ten Josephson element comprises a loop, with exactly one Josephson junction of first size on one half of the loop and at least two Josephson junctions of a second size on a second half of the loop, the second size being larger than the first size, a flux bias line configured to generate a magnetic flux threading each of the at least one loop, and a set of resistors coupled with the flux bias line.

A bandpass parametric amplifier circuit includes a plurality of unit cells. At least one unit cell includes a first inductor having a first node coupled to a center conductor and a second node coupled to ground. There is a first capacitor having a first node coupled to the center conductor and a second node coupled to ground. There is a second inductor having a first node coupled to the center conductor. A second capacitor has a first node coupled to a second node of the second inductor. The second capacitor and the second inductor are in series with the center conductor.

A non-reciprocal filter with parametric amplification to obtain non-reciprocal propagation of forward and reverse signals is disclosed. The non-reciprocal filter may include two asymmetrical transmission lines and a current source. The filter, when implemented in the acoustics domain using surface acoustic waves (SAW), may operate in a phase-coherent or a phase-incoherent degenerate mode, providing low insertion loss and high decibels of isolation.

A non-reciprocal filter with parametric amplification to obtain non-reciprocal propagation of forward and reverse signals is disclosed. The non-reciprocal filter may include two asymmetrical transmission lines and a current source. The filter, when implemented in the acoustics domain using surface acoustic waves (SAW), may operate in a phase-coherent or a phase-incoherent degenerate mode, providing low insertion loss and high decibels of isolation.

A four-wave mixing transmission line (3) including: an input (15, 17, 19) arranged to receive: a first pump signal (7a) having a first pump frequency; a second pump signal (7b), having a second pump frequency, different to the first pump frequency; and an input signal to be amplified (5); a non-linear medium (3a) having an intrinsic dispersion relationship, the medium (3a) arranged to allow interaction between the input signal (5), the first pump signal (7a) and the second pump signal (7b), such that the input signal (5) is amplified and an idler signal (9) is generated and amplified; and a plurality of dispersion control elements (31, 33, 49), the dispersion control elements (31, 33, 49) arranged to alter the dispersion relationship of the medium (3a) to diverge from the intrinsic dispersion relationship at one or more frequencies, such that the total phase difference between the input signal, (5) the first pump signal (7a), the second pump signal (7b) and the idler signal (9) is kept at zero or substantially zero as the first pump signal (7a), the second pump signal (7b), the input signal (5) and the idler signal (9) propagate down the transmission line (3).