A circuit for driving a switched transistor comprises: a level shifter comprising at least one transistor, the level shifter configured to convert an input pulse to a pulse having a greater voltage swing than the input pulse and shift a voltage level of the converted pulse; and a pulse shaping filter coupled between the level shifter and the gate of the switched transistor, the pulse shaping filter tuned to cancel or reduce an impedance of the gate of the switched transistor. The switched transistor and/or the at least one transistor are a GaN High Electron Mobility Transistor (HEMT).

A circuit for driving a switched transistor comprises: a level shifter comprising at least one transistor, the level shifter configured to convert an input pulse to a pulse having a greater voltage swing than the input pulse and shift a voltage level of the converted pulse; and a pulse shaping filter coupled between the level shifter and the gate of the switched transistor, the pulse shaping filter tuned to cancel or reduce an impedance of the gate of the switched transistor. The switched transistor and/or the at least one transistor are a GaN High Electron Mobility Transistor (HEMT).

A communicate device includes transmitters and a receiver. The first transmitter is coupled to a first 90 phase shifter that is also coupled to a first antenna, and to a second 90 phase shifter that is also coupled to a first node. The second transmitter is coupled to a third 90 phase shifter that is also coupled to a second antenna, and to a fourth 90 phase shifter that is also coupled to the first node. The receiver is coupled to a fifth 90 phase shifter that is also coupled to the first antenna, and to a sixth 90 phase shifter that is also coupled to the second antenna. A non-reciprocal element, coupled between the receiver and the first node, provides a 90 phase shift from the receiver to the first node and a 90 phase shift from the first node to the receiver.

A communicate device includes transmitters and a receiver. The first transmitter is coupled to a first 90 phase shifter that is also coupled to a first antenna, and to a second 90 phase shifter that is also coupled to a first node. The second transmitter is coupled to a third 90 phase shifter that is also coupled to a second antenna, and to a fourth 90 phase shifter that is also coupled to the first node. The receiver is coupled to a fifth 90 phase shifter that is also coupled to the first antenna, and to a sixth 90 phase shifter that is also coupled to the second antenna. A non-reciprocal element, coupled between the receiver and the first node, provides a 90 phase shift from the receiver to the first node and a 90 phase shift from the first node to the receiver.

A microelectromechanical resonant circulator device is providing, having a substrate, and at least three electrical ports supported on the substrate. At least three electromechanical resonator elements are connected with associated switch elements and an associated port. The switch elements are operative to provide commutation over time of the electromechanical resonator elements.

A microelectromechanical resonant circulator device is providing, having a substrate, and at least three electrical ports supported on the substrate. At least three electromechanical resonator elements are connected with associated switch elements and an associated port. The switch elements are operative to provide commutation over time of the electromechanical resonator elements.

A wide band radio frequency (RF) circulator, including: a first stage having four ports; and a second stage having four ports, wherein the first stage and the second stage are connected via a pair of conductive delay lines including a reciprocal delay line placed on a dielectric substrate and a non-reciprocal delay line placed on ferrite substrate, wherein each of the first stage and the second stage include a pair of couplers.

A wide band radio frequency (RF) circulator, including: a first stage having four ports; and a second stage having four ports, wherein the first stage and the second stage are connected via a pair of conductive delay lines including a reciprocal delay line placed on a dielectric substrate and a non-reciprocal delay line placed on ferrite substrate, wherein each of the first stage and the second stage include a pair of couplers.

Sequentially-Switched Delay Line (SSDL) can realize passive, nonmagnetic and non-reciprocal components for electromagnetic waves over ultra-wideband through the breaking of the time-reversal symmetry. A SSDL structure with six sections of transmission lines and five Single Pole Double Throw (SPDT) switches has been proposed as a three-port circulator in the literature. In this disclosure, a simpler structure consisting of only two sections of transmission lines with two switches is proposed, which can operate as a two-port non-reciprocal phase shifter (gyrator) with two SPDT switches, a three-port circulator with one DPDT switch and one SPDT switch, or a four-port circulator with two DPDT switches. Simulation results for one design at radio frequency demonstrated the expected non-reciprocal behavior from DC to 1.5 GHz for aforementioned three configurations.

Sequentially-Switched Delay Line (SSDL) can realize passive, nonmagnetic and non-reciprocal components for electromagnetic waves over ultra-wideband through the breaking of the time-reversal symmetry. A SSDL structure with six sections of transmission lines and five Single Pole Double Throw (SPDT) switches has been proposed as a three-port circulator in the literature. In this disclosure, a simpler structure consisting of only two sections of transmission lines with two switches is proposed, which can operate as a two-port non-reciprocal phase shifter (gyrator) with two SPDT switches, a three-port circulator with one DPDT switch and one SPDT switch, or a four-port circulator with two DPDT switches. Simulation results for one design at radio frequency demonstrated the expected non-reciprocal behavior from DC to 1.5 GHz for aforementioned three configurations.