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.

Remote compensators for mobile devices are provided. In certain embodiments, a remote compensator includes a first balun, a cable-side circulator including an output that provides a transmit signal and an input that receives an amplified receive signal, a first phase shifter, a second phase shifter, a first antenna-side circulator, a second antenna-side circulator, transmit amplifier circuitry, and a receive amplifier that generates the amplified receive signal by amplifying a first receive signal from the first antenna-side circulator and a second receive signal from the second antenna-side circulator. The transmit amplifier circuitry includes an input that receives the transmit signal, a first output connected to a first end of a winding of the first balun through the first antenna-side circulator and the first phase shifter, and a second output connected to a second end of the winding of the first balun through the second phase shifter and the second antenna-side circulator.

Remote compensators for mobile devices are provided. In certain embodiments, a remote compensator includes a first balun, a cable-side circulator including an output that provides a transmit signal and an input that receives an amplified receive signal, a first phase shifter, a second phase shifter, a first antenna-side circulator, a second antenna-side circulator, transmit amplifier circuitry, and a receive amplifier that generates the amplified receive signal by amplifying a first receive signal from the first antenna-side circulator and a second receive signal from the second antenna-side circulator. The transmit amplifier circuitry includes an input that receives the transmit signal, a first output connected to a first end of a winding of the first balun through the first antenna-side circulator and the first phase shifter, and a second output connected to a second end of the winding of the first balun through the second phase shifter and the second antenna-side circulator.

In accordance with some embodiments, non-reciprocal circulators are provided, the circulators comprising: a 3X/4-long ring section having a first end and a second end, wherein is an operating wavelength of the non-reciprocal circulator; and a N-path filter having a first port, a second port, and N-paths, each of the N-paths being connected to the first port and the second port. In some of these embodiments, the 3/4-long ring section includes a transmit port, an antenna port, and a receive port. In some of these embodiments, the transmit port is /4 away from the antenna port. In some of these embodiments, the antenna port is /4 away from the receive port. In some of these embodiments, the receive port is at the first port of the N-path filter.

In accordance with some embodiments, non-reciprocal circulators are provided, the circulators comprising: a 3X/4-long ring section having a first end and a second end, wherein is an operating wavelength of the non-reciprocal circulator; and a N-path filter having a first port, a second port, and N-paths, each of the N-paths being connected to the first port and the second port. In some of these embodiments, the 3/4-long ring section includes a transmit port, an antenna port, and a receive port. In some of these embodiments, the transmit port is /4 away from the antenna port. In some of these embodiments, the antenna port is /4 away from the receive port. In some of these embodiments, the receive port is at the first port of the N-path filter.

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.

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.