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 is provided. The circulator includes 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 reciprocal delay lines, and wherein each of the first stage and the second stage includes a pair of couplers.

A wide band radio frequency (RF) circulator is provided. The circulator includes 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 reciprocal delay lines, and wherein each of the first stage and the second stage includes a pair of couplers.

A transmission line is provided with a fixed physical length and a programmable electrical length for achieving a programmable time delay. The transmission line can include a dielectric and a biasing device disposed across the dielectric, and the biasing device can dynamically and continuously vary an absolute level of a bias voltage across the dielectric to vary a dielectric constant of the dielectric, which can vary a time delay of the transmission line. In some embodiments, the biasing device can modulate the bias voltage from a positive voltage to a negative voltage at a frequency and with waveform characteristics that prevent such modulation from interfering with a signal propagating through the dielectric, that prevent the bias voltage from unintentionally varying the time delay of the transmission line when the absolute level of the bias voltage is constant, and that prevents ion impurities within the dielectric from accumulating on bias electrodes.

A transmission line is provided with a fixed physical length and a programmable electrical length for achieving a programmable time delay. The transmission line can include a dielectric and a biasing device disposed across the dielectric, and the biasing device can dynamically and continuously vary an absolute level of a bias voltage across the dielectric to vary a dielectric constant of the dielectric, which can vary a time delay of the transmission line. In some embodiments, the biasing device can modulate the bias voltage from a positive voltage to a negative voltage at a frequency and with waveform characteristics that prevent such modulation from interfering with a signal propagating through the dielectric, that prevent the bias voltage from unintentionally varying the time delay of the transmission line when the absolute level of the bias voltage is constant, and that prevents ion impurities within the dielectric from accumulating on bias electrodes.

An optical device includes a first multi-mode waveguide, a first optical coupler coupled to the first multi-mode waveguide, the first coupler being tapered and curved, and a first single-mode waveguide having a first end coupled to the first optical coupler. The optical device may be used in an optical delay device. A method of propagating light in a first multi-mode waveguide toward a first optical coupler, propagating the light in the first optical coupler toward a first single-mode waveguide, the first optical coupler being tapered and curved, and propagating the light along the first single-mode waveguide is also disclosed.

An optical device includes a first multi-mode waveguide, a first optical coupler coupled to the first multi-mode waveguide, the first coupler being tapered and curved, and a first single-mode waveguide having a first end coupled to the first optical coupler. The optical device may be used in an optical delay device. A method of propagating light in a first multi-mode waveguide toward a first optical coupler, propagating the light in the first optical coupler toward a first single-mode waveguide, the first optical coupler being tapered and curved, and propagating the light along the first single-mode waveguide is also disclosed.

A wide band radio frequency (RF) circulator is provided. The circulator includes 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 reciprocal delay lines, and wherein each of the first stage and the second stage includes a pair of couplers.

A wide band radio frequency (RF) circulator is provided. The circulator includes 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 reciprocal delay lines, and wherein each of the first stage and the second stage includes a pair of couplers.

A structure of transmission line includes a first transmission line, a second transmission line and an interlayer via. The first transmission line includes a first line segment, a second segment and a first signal via. The second transmission line includes a third line segment, a fourth segment and a second signal via. Both of the first line segment and the third line segment are disposed in a first signal transmission layer and extend along a first direction. Both of the second line segment and the fourth line segment are disposed in a second signal transmission layer and extend along a second direction. The first signal via is connected to the first line segment and the second line segment. The second signal via is connected to the third line segment and the fourth line segment. The interlayer via is adjacent to the first line segment or the second line segment.