Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of bismuth can be added into specific sites in the crystal structure of the synthetic garnet in order to boost certain properties, such as the dielectric constant and magnetization. Accordingly, embodiments of the disclosed materials can be used in high frequency applications, such as in base station antennas.

A compact six-port Photonic Crystal (PhC) circulator includes a hexagonal PhC branch waveguide and six waveguide ports, wherein six PhC branch waveguides respectively correspond to the six waveguide ports, and the six waveguide ports respectively are symmetrically distributed at the periphery of PhCs. One second dielectric material column is arranged at the center of the hexagonal PhC waveguide. Six identical magneto-optical material columns respectively are arranged at first adjacent positions of the second dielectric material column. Six identical third dielectric material columns respectively are arranged at second adjacent positions of the second dielectric material column. An electromagnetic signal is inputted from any one of the waveguide ports and is outputted from the next waveguide port adjacent thereto, while the remaining waveguide ports are in a signal isolated state, thus forming unidirectional circular transmission.

Input/output terminals 6a, 6b and 6c are formed within portions of cutouts 5a, 5b and 5c provided in a ground conductor 5 on the underside of a magnetic material 3; signal conductors 9a, 9b and 9c are formed within portions of cutouts 8a, 8b and 8c provided in a ground conductor 8 on the top surface of a dielectric substrate 7 at the same places as the cutouts 5a, 5b and 5c of the ground conductor; through holes 10a, 10b and 10c electrically connect a center conductor 4 to the input/output terminals 6a, 6b and 6c; metal bumps 11a, 11b and 11c electrically connect the input/output terminals 6a, 6b and 6c to the signal conductors 9a, 9b and 9c facing each other; and metal bumps 16 electrically connect the ground conductor 5 to the ground conductor 8.

Input/output terminals 6a, 6b and 6c are formed within portions of cutouts 5a, 5b and 5c provided in a ground conductor 5 on the underside of a magnetic material 3; signal conductors 9a, 9b and 9c are formed within portions of cutouts 8a, 8b and 8c provided in a ground conductor 8 on the top surface of a dielectric substrate 7 at the same places as the cutouts 5a, 5b and 5c of the ground conductor; through holes 10a, 10b and 10c electrically connect a center conductor 4 to the input/output terminals 6a, 6b and 6c; metal bumps 11a, 11b and 11c electrically connect the input/output terminals 6a, 6b and 6c to the signal conductors 9a, 9b and 9c facing each other; and metal bumps 16 electrically connect the ground conductor 5 to the ground conductor 8.

A method of fabricating a portion of magnetically controlled signal distribution device includes receiving a substrate and screen printing a low-k dielectric spacer over an upper surface of the surface from a low-k dielectric paste. The method also includes firing the substrate after the spacer has been screen printed thereon, forming an adhesive layer on top of the spacer and securing a magnet to a top of the adhesive layer.

A method of fabricating a portion of magnetically controlled signal distribution device includes receiving a substrate and screen printing a low-k dielectric spacer over an upper surface of the surface from a low-k dielectric paste. The method also includes firing the substrate after the spacer has been screen printed thereon, forming an adhesive layer on top of the spacer and securing a magnet to a top of the adhesive layer.

A circulator, comprising: a gyrator having a first side (1S) and a second side (2S) connected to a third port; a first transmission line section (TLS) having a 1 S connected to the 1 S of the gyrator and a 2S connected to a first port; a second TLS having a 1S connected to the first port and having a 2S connected to a second port; a third TLS having a 1S connected to the second port and having a 2S connected to the third port; a first cancellation path (CP) that is connected between the first port and the third port and introduces a current that is 90 degrees out of phase with a first voltage at the first port; and a second CP that is connected between the second port and the third port and introduces a current that is orthogonal to the current introduces by the first CP.

A circulator, comprising: a gyrator having a first side (1S) and a second side (2S) connected to a third port; a first transmission line section (TLS) having a 1 S connected to the 1 S of the gyrator and a 2S connected to a first port; a second TLS having a 1S connected to the first port and having a 2S connected to a second port; a third TLS having a 1S connected to the second port and having a 2S connected to the third port; a first cancellation path (CP) that is connected between the first port and the third port and introduces a current that is 90 degrees out of phase with a first voltage at the first port; and a second CP that is connected between the second port and the third port and introduces a current that is orthogonal to the current introduces by the first CP.

A circuit comprising a differential transmission line and eight switches provides non-reciprocal signal flow. In some embodiments, the circuit can be driven by four local oscillator signals using a boosting circuit. The circuit can be used to form a gyrator. The circuit can be used to form a circulator. The circuit can be used to form three-port circulator than can provide direction signal flow between a transmitter and an antenna and from the antenna to a receiver. The three-port circulator can be used to implement a full duplex transceiver that uses a single antenna for transmitting and receiving.

A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator. The method also includes generating an RF output signal using at least one of multiple reflective filter elements. Each reflective filter element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a filtered RF signal to the at least one non-reciprocal circulator. The reflective filter elements include amplitude change reflectors configured to modify amplitudes of the RF signal at different frequencies. The RF output signal represents the RF input signal as modified by the at least one of the reflective filter elements.