Circuits for protecting devices, such as gallium nitride (GaN) devices, and operating methods thereof are described. Such circuits may include a temperature sensor configured to sense the temperature of at least a portion of a device, and a phase shifter configured to shift the phase of the signal output by the device, when the sensed temperature is outside a safe temperature range, e.g., above a predefined temperature threshold. The phase may be shifted discretely or continuously. These circuits safeguard devices from damaging operating conditions to prolong the operating life of the protected devices.

A substrate integrated waveguide (SIW) for phase shifter for millimeter wave applications has a waveguide with a plurality of curved sections and which passes through the substrate from a wave entry port to a wave exit port. The plurality of curved sections forms a serpentine path of curves in a first direction followed by curves in a second direction which are opposite the first direction. Phase shifting elements are positioned in the waveguide in each of the curved sections. The phase shifting elements may take the form of PIN diodes or a pattern of liquid metal filled vias in the waveguide.

A substrate integrated waveguide (SIW) for phase shifter for millimeter wave applications has a waveguide with a plurality of curved sections and which passes through the substrate from a wave entry port to a wave exit port. The plurality of curved sections forms a serpentine path of curves in a first direction followed by curves in a second direction which are opposite the first direction. Phase shifting elements are positioned in the waveguide in each of the curved sections. The phase shifting elements may take the form of PIN diodes or a pattern of liquid metal filled vias in the waveguide.

Examples disclosed herein relate to a phase shift network system including a phase shift network having a plurality of distributed varactor networks, each distributed varactor network capable of providing a phase shift range in a millimeter wave spectrum, and a plurality of switches coupled to the phase shift network, each switch to activate a distributed varactor network from the plurality of distributed varactor networks to generate a given phase shift within the phase shift range.

A phase shifter includes a radio frequency input transmission line, a radio frequency output transmission line, and a first branch and a second branch coupled in parallel between the radio frequency input transmission line and the radio frequency output transmission line, the first branch includes first switch components and first transmission lines coupled in series, and the second branch includes a second transmission line including a first terminal coupled to the radio frequency input transmission line and a second terminal, a third transmission line including a third terminal coupled to the second terminal and a fourth terminal coupled to the radio frequency output transmission line, second switch components, where one terminal of each of the second switch components is coupled to a connection node of the second transmission line and the third transmission line, and the other terminal is coupled to a corresponding grounding component.

A first phase shift circuit (2) converts impedance to achieve impedance matching between a third terminal (1c) of a 90-degree hybrid circuit (1) and a first terminal (4a) of a first nonlinear element (4), and shifts a phase of a radio wave by 180 degrees, and a second phase shift circuit (3) converts impedance to achieve impedance matching between a fourth terminal (1d) of the 90-degree hybrid circuit (1) and a first terminal (5a) of a second nonlinear element (5), and shifts a phase of a radio wave by 90 degrees. As a result of this configuration, a conversion loss of radio waves can be reduced.

A first phase shift circuit (2) converts impedance to achieve impedance matching between a third terminal (1c) of a 90-degree hybrid circuit (1) and a first terminal (4a) of a first nonlinear element (4), and shifts a phase of a radio wave by 180 degrees, and a second phase shift circuit (3) converts impedance to achieve impedance matching between a fourth terminal (1d) of the 90-degree hybrid circuit (1) and a first terminal (5a) of a second nonlinear element (5), and shifts a phase of a radio wave by 90 degrees. As a result of this configuration, a conversion loss of radio waves can be reduced.

A system utilizes e-fuses in phase shifter elements of a phased array antenna to achieve a desired direction of a beam formed by the phased array antenna. A phase shifter element includes: a transmission line structure comprising a signal line, a ground return line, a capacitance line, and an inductance return line; and at least one e-fuse connected to the transmission line structure, wherein the phase shifter element has a first phase shift when the at least one e-fuse is unbroken and a second phase shift, different from the first phase shift, when the at least one e-fuse is broken.

A digital phase shifter includes a plurality of digital phase shift circuit groups in which a plurality of digital phase shift circuits are connected in cascade, one or more relay digital phase shift circuits (digital phase shift circuits) provided between two digital phase shift circuit groups, and two or more bend-type connection units configured to connect one of the two digital phase shift circuit group and the relay digital phase shift circuit and connect the other of the two digital phase shift circuit groups and the relay digital phase shift circuit. At least one of the digital phase shift circuits constituting at least one digital phase shift circuit group and the relay digital phase shift circuit is a mitigation circuit that mitigates the distribution of phase shift amounts.

A digital phase shifter includes a plurality of digital phase shift circuit groups in which a plurality of digital phase shift circuits are connected in cascade, one or more relay digital phase shift circuits (digital phase shift circuits) provided between two digital phase shift circuit groups, and two or more bend-type connection units configured to connect one of the two digital phase shift circuit group and the relay digital phase shift circuit and connect the other of the two digital phase shift circuit groups and the relay digital phase shift circuit. At least one of the digital phase shift circuits constituting at least one digital phase shift circuit group and the relay digital phase shift circuit is a mitigation circuit that mitigates the distribution of phase shift amounts.