Non-reciprocal circuit elements

Abstract

To provide a non-reciprocal circuit element having a wide-bandwidth frequency characteristic.SOLUTION: A non-reciprocal circuit element of the present invention is a circuit element that comprises a non-reciprocal part transmitting a signal only in a specific direction, and having a non-reciprocal transmission direction characteristic where a transmission is not performed in a reverse direction, and the non-reciprocal part is constructed by: a ferrite; an electromagnet applying a current magnetic field to the ferrite; and a conductor in which a plurality of terminal ends arranged cross in an insulation state respectively to the ferrite are short-circuited. The non-reciprocal circuit element comprises: an irreversible circuit part that is connected between an input and output port and the other end of the conductor where each terminal end is short-circuited, and does not have polarization in a transmission direction; and a DC power supply control part that controls a DC current supplied to the electromagnet. The DC power supply control part controls the DC current supplied to the electromagnet, and controls the DC magnetic field applied to the electromagnet. By the control of the DC magnetic field, a center frequency of a frequency characteristic of the non-reciprocal circuit element is matched to a frequency of a high frequency signal to reduce a loss in an insertion of the non-reciprocal circuit element.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a non-reciprocal circuit element of a ferrite device such as an isolator or a circulator, and in particular to a non-reciprocal circuit element composed of lumped constant elements. [Background technology]

[0002] Known non-reciprocal circuit elements that utilize the Faraday effect of ferrite include isolators that absorb reflected waves from a load to ensure stable operation of oscillators and amplifiers, and circulators that transmit high-frequency signals unidirectionally to two-terminal elements. Circulators are basic ferrite devices because they can be used as isolators by terminating one end with a resistor.

[0003] A known three-port lumped-element circulator is composed of a permanent magnet, ferrite to which a DC magnetic field is applied by the permanent magnet, three central conductors arranged to cross the ferrite in an electrically insulated state, and matching capacitors electrically connected to the central conductors. The operating frequency is adjusted by the capacitance values ​​of the capacitors connected in parallel to the three central conductors (Patent Document 1, Patent Document 2).

[0004] FIG. 11(a) is a diagram showing the configuration of a three-port lumped constant circulator, and FIG. 11(b) shows the equivalent circuit. 11(a), a lumped-parameter circulator 101 includes ferrite elements 102 (102a, 102b), a permanent magnet 104 that applies a DC magnetic field to the ferrite element 102, conductors 103 (103a-103c) that are electrically insulated from the ferrite element 102, and capacitors 105 (105a-105c) that are connected in parallel to the conductors 103. The conductors 103 include three conductors: a first conductor 103a, a second conductor 103b, and a third conductor 103c. The three conductors cross each other at 120° intervals and are insulated from one another. One end of each of the conductors 103a-103c is connected to a first port P1, a second port P2, and a third port P3, respectively, and the other end is short-circuited. Capacitors 105a-105c are connected in parallel to the conductors 103a-103c, and a parallel resonant circuit is formed by the inductance of the conductors and the capacitance of the capacitors.

[0005] 11(b) shows an equivalent circuit of a parallel resonant lumped parameter circulator, which is composed of an ideal circulator 100 and parallel resonant circuits 106 (106a to 106c). Each parallel resonant circuit 106 (106a to 106c) is composed of lumped parameter elements, namely, inductors Lp (Lp1, Lp2, Lp3) and capacitance constants Cp (Cp1, Cp2, Cp3). The frequency characteristics of the lumped parameter circulator are determined by the lumped parameter elements.

[0006] In a three-port lumped constant circulator, a high-frequency signal input from the first port P1 is output from the third port P3, a high-frequency signal input from the third port P3 is output from the second port P2, and a high-frequency signal input from the second port P2 is output from the first port P1. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-55222 [Patent Document 2] International Publication No. 2016 / 158044 Summary of the Invention [Problem to be solved by the invention]

[0008] The characteristics of non-reciprocal circuit devices are evaluated by the insertion loss of the forward direction and the isolation of the reverse direction. The insertion loss of the forward direction is evaluated as a pass characteristic, while the reverse loss characteristic of a circulator is evaluated by the isolation when a termination resistor is connected to one end.

[0009] Conventional non-reciprocal circuit elements have a narrow operating frequency range, and therefore have the problem of being unable to accommodate the variable frequency range of a high frequency power source.

[0010] The characteristics of a non-reciprocal circuit element have frequency characteristics determined by the capacitance value of the matching capacitor of the parallel resonant circuit, and the frequency band in which effective frequency characteristics are obtained depends on the circuit characteristics of the parallel resonant circuit. Since the operating frequency range of a non-reciprocal circuit element is narrow and a wide operating frequency range cannot be obtained, it is difficult to effectively operate the entire variable frequency range of a high-frequency power supply with a single parallel resonant circuit.

[0011] Fig. 12 is a diagram for explaining the narrow-band characteristics of a conventional non-reciprocal circuit device, and shows the frequency characteristics of the circulator as a pass characteristic with respect to frequency. Note that the frequency characteristic diagram in Fig. 12 is a schematic diagram and does not show the actual frequency characteristics.

[0012] Figure 12(a) shows the state when the center frequency fc of the frequency response, which represents the passband characteristics of a circulator, matches the frequency f of the high-frequency power source. Normally, when the center frequency fc of the circulator's frequency response is set to match the frequency f of the high-frequency power source, the passband characteristics degrade when the frequency f of the high-frequency power source deviates from fc. Due to this frequency response, as shown in Figure 12(b), the passband characteristics when the frequency f of the high-frequency power source deviates from the center frequency fc (fc±Δf) exhibit a narrowband characteristic compared to when the frequency f of the high-frequency power source matches the center frequency fc, because the passband characteristics are reduced by the insertion loss ΔPs due to the impedance mismatch of the non-reciprocal circuit element. Because of this narrowband characteristic, a non-reciprocal circuit element cannot provide good passband characteristics over a wide frequency range, making it difficult to accommodate the variable frequency range of the high-frequency power source.

[0013] Therefore, an object of the present invention is to broaden the frequency characteristics of a non-reciprocal circuit device by reducing the insertion loss of the non-reciprocal circuit device. [Means for solving the problem]

[0014] The non-reciprocal circuit element of the present invention is a circuit element having a non-reciprocal section that has a non-reciprocal transmission direction characteristic that transmits signals only in a specific direction and not in the reverse direction, and the non-reciprocal section is composed of ferrite, an electromagnet that applies a DC magnetic field to the ferrite, and multiple conductors with short-circuited ends that are arranged to cross the ferrite in an insulated state.

[0015] The non-reciprocal circuit device of the present invention includes a reciprocal circuit section that is connected between an input / output port and the other end of the short-circuit terminated conductor and has no bias in the transmission direction, and a DC power supply control section that controls the DC current supplied to the electromagnet.

[0016] (A) Irreversible part The conductor connected to the input port of the non-reciprocal section generates a high-frequency magnetic field in response to a high-frequency signal supplied from a high-frequency power source. The high-frequency magnetic field generated by the conductor and a DC magnetic field generated by an electromagnet are applied to the ferrite.

[0017] The high frequency magnetic field becomes a positive circularly polarized magnetic field that rotates clockwise in the direction of the DC magnetic field and a negative circularly polarized magnetic field that rotates counterclockwise.

[0018] Electromagnetic waves propagating through ferrite magnetized by a DC magnetic field have different permeability μ depending on whether the rotation direction of the two circularly polarized waves is the same or opposite to the rotation direction of the ferrite's spin magnetic moment, and the path of the polarization plane of the electromagnetic waves curves, changing the direction of propagation of the electromagnetic waves.

[0019] The complex permeability μ of ferrite is the permeability μ + and the permeability μ for a negative circularly polarized magnetic field - By applying a DC magnetic field, the circularly polarized magnetic permeability μ + becomes smaller, and the negative circularly polarized permeability μ - becomes larger.

[0020] (B) DC power supply control section The DC power supply control unit included in the non-reciprocal circuit device of the present invention controls the DC current supplied to the electromagnet, thereby varying the intensity of the DC magnetic field applied to the ferrite. By varying the intensity of the DC magnetic field, the circularly polarized magnetic permeability μ + and negative circularly polarized permeability μ - By changing the difference between these, the transmission characteristics between the forward and reverse terminals can be varied.

[0021] Because the characteristics of magnetic permeability μ (circularly polarized magnetic permeability μ±) relative to magnetic field strength H depend on the operating frequency, by changing the magnetic field strength H of the DC magnetic field applied to the ferrite using an electromagnet, it is possible to control the shift of the center frequency of the frequency characteristics of the non-reciprocal section to the higher or lower frequency side. In this way, by matching the center frequency of the non-reciprocal section to the high frequency of the high-frequency signal input to the non-reciprocal circuit element, the pass characteristics of the non-reciprocal circuit element are improved.

[0022] By controlling the DC current supplied to the electromagnet in accordance with changes in the frequency of the high-frequency signal from the high-frequency power supply and varying the strength of the DC magnetic field generated by the electromagnet, the center frequency of the non-reciprocal part is adjusted to the frequency of the high-frequency signal, thereby broadening the frequency characteristics of the non-reciprocal circuit element in response to changes in the frequency of the high-frequency signal from the high-frequency power supply and suppressing fluctuations in the signal strength of the high-frequency signal output within the variable frequency range of the high-frequency power supply.

[0023] The non-reciprocal circuit device of the present invention can achieve the effect of suppressing thermomagnetic characteristics due to temperature fluctuations in addition to the effect of widening the frequency characteristics described above.

[0024] When a DC magnetic field is applied to ferrite using a permanent magnet, the frequency characteristics of the nonreciprocal circuit device change with temperature fluctuations due to the thermomagnetic properties of the permanent magnet. In contrast, the nonreciprocal circuit device of the present invention controls the DC current supplied to the electromagnet using a DC power supply control unit, making it possible to vary the DC magnetic field generated by the electromagnet, thereby suppressing the thermomagnetic properties caused by temperature fluctuations.

[0025] (C) Reversible circuit section The reciprocal circuit section is composed of a parallel resonant circuit consisting of the inductance of the conductor in the non-reciprocal section and a capacitor connected in parallel. The parallel resonant circuit (a) functions as a resonator that determines the frequency characteristics, and (b) as an impedance matcher that matches the input impedance to the characteristic impedance of the input / output transmission line.

[0026] The inductor Lp of the inductance of the parallel resonant circuit and the capacitance constant Cp of the capacitor are determined by the irreversibility index η and the frequency ω as shown in the following equations (1) to (3).

number

[0027] Here, the complex permeability μ of ferrite is expressed as μ = μ'-jμ". The real part μ' of the complex permeability μ indicates the magnetization response, and the imaginary part μ" indicates the magnetic loss. Circularly polarized permeability μ + The real part μ + ′ and negative circularly polarized permeability μ - The real part μ - ' and the permeability difference Δμ (= μ - ′-μ + The absolute value of |Δμ| of |′| indicates irreversibility.

[0028] (Ca: function of resonator) The function of the resonator is to vary the resonant frequency of the parallel resonant circuit, thereby varying the center frequency of the reversible circuit. Equations (1) and (2) show that the inductor Lp and capacitance constant Cp contain frequency ω as a parameter. This means that the resonant frequency of the parallel resonant circuit can be varied by changing the values ​​of the inductor Lp and capacitance constant Cp that make up the parallel resonant circuit.

[0029] By changing the values ​​of the inductor Lp and / or the capacitance constant Cp, the center frequency of the reciprocal circuit unit is adjusted to match the frequency of the high-frequency signal from the high-frequency power source input to the non-reciprocal circuit device. By adjusting the center frequency of the reciprocal circuit unit to the frequency of the high-frequency signal from the high-frequency power source input to the non-reciprocal circuit device, the pass characteristics of the non-reciprocal circuit device are improved.

[0030] In the nonreciprocal circuit device of the present invention, the nonreciprocal part mainly controls the center frequency, and the reciprocal part controls the center frequency by the resonator function as an additional function. Therefore, the center frequency can be controlled not only by the nonreciprocal part that controls the magnetic field strength of the DC magnetic field of the electromagnet, but also by the resonator function of the reciprocal circuit part in addition to the control by the nonreciprocal part.

[0031] (Cb: Impedance matching function) The parallel resonant circuit of the reciprocal circuit section also functions as an impedance matcher that matches the impedance between each conductor of the non-reciprocal section and the input / output port side.

[0032] Since the inductance Lp of the parallel resonant circuit is determined by the inductance of the conductor of the non-reciprocal part, impedance matching is achieved by setting the capacitance constant Cp of the capacitor of the parallel resonant circuit based on the frequency of the high-frequency signal from the high-frequency power supply.

[0033] When adjusting the center frequency of the reversible circuit section to the frequency of the high-frequency signal from the high-frequency power supply, if the center frequency is changed by changing the DC magnetic field of the electromagnet in the non-reversible section, impedance mismatching may occur in the transmission line system including the reversible circuit section, resulting in insertion loss.To address such impedance mismatching, the reversible circuit section functions as an impedance matching box to match the impedance, thereby reducing the insertion loss due to impedance mismatching.

[0034] (Cc: Constant change section) The non-reciprocal circuit device of the present invention includes a constant changing section that changes the capacitance of the capacitor in the reciprocal circuit section.

[0035] The constant changing unit changes the capacitance of the capacitor in the reversible circuit unit based on the frequency of the high frequency signal from the high frequency power supply, thereby changing the resonant frequency of the parallel resonant circuit.

[0036] The constant change unit changes the resonant frequency of the non-reciprocal unit. (c1) A function for changing the frequency characteristics to match the center frequency with the frequency of the high-frequency signal of the high-frequency power source; and (c2) Impedance matching function to match the impedance of input and output ports It plays a key role.

[0037] The main function of the non-reciprocal section to change the variable frequency characteristics is achieved by controlling the direct current supplied to the electromagnet to change the center frequency.

[0038] In contrast, the function (c1) for changing the frequency characteristics acts as an additional function. When the frequency of the high-frequency power supply fluctuates around the center frequency of the non-reciprocal circuit device, or when the frequency of the high-frequency power supply varies within the variable frequency range, the DC power supply control unit controls the DC magnetic field generated by the electromagnet in the non-reciprocal section, and the constant changing unit sets the capacitance of the capacitor in the reciprocal circuit section to optimize the frequency characteristics and broaden the frequency band of the non-reciprocal circuit device.

[0039] The impedance matching function (c2) suppresses the degradation of the passing characteristics of high frequency signals due to changes in frequency characteristics, etc.

[0040] (D) Control of DC current The control of the DC current supplied to the electromagnet by the DC power supply control unit includes (Da) a control mode based on the amount of electricity supplied to the high-frequency signal input to the non-reciprocal unit, or (Db) a control mode based on the frequency of the high-frequency signal supplied to the non-reciprocal unit.

[0041] (Da: Control based on the amount of electricity supplied) The DC power supply control unit controls the current value of the DC current based on the amount of electricity supplied by the high-frequency signal input from the high-frequency power supply to the non-reciprocal unit, thereby varying the strength of the DC magnetic field, thereby adjusting the center frequency of the frequency characteristics of the non-reciprocal unit to the frequency of the high-frequency signal from the high-frequency power supply.

[0042] A power supply detector is provided between the high frequency power supply and the reversible circuit connected to the input port, and this power supply detector detects the amount of power supply electricity. The amount of power supply electricity can be any one of voltage, current, power, and reflectance. If there is a discrepancy between the center frequency of the frequency characteristics of the non-reversible part and the frequency of the high frequency signal from the high frequency power supply, insertion loss occurs, and the amount of power supply electricity, such as voltage, current, power, and reflectance, decreases.

[0043] The power supply detection unit detects the amount of power supply electricity and feeds back the detected amount of power supply electricity to the DC power supply control unit. The DC power supply control unit compares the amount of power supply electricity fed back from the power supply detection unit with a set value and controls the current value of the DC current supplied to the electromagnet so that the amount of power supply electricity becomes the set value. The set value can be a set voltage value, a set current value, a set power value, or a set reflectivity. Each set value is set based on the respective value when there is no insertion loss.

[0044] (Db: Frequency-based control) The DC power supply control unit controls the current value of the DC current based on the frequency of the high-frequency signal input to the non-reciprocal unit, thereby varying the strength of the DC magnetic field, thereby adjusting the center frequency of the frequency characteristics of the non-reciprocal unit to the frequency of the high-frequency signal from the high-frequency power supply.

[0045] The frequency characteristics of the non-reciprocal part vary depending on the frequency of the high-frequency signal input to the high-frequency power supply. Therefore, by controlling the current value of the DC current according to the frequency of the high-frequency signal and varying the strength of the DC magnetic field, the center frequency of the frequency characteristics of the non-reciprocal part can be adjusted to the frequency of the high-frequency signal from the high-frequency power supply, even if the frequency of the high-frequency signal changes. The control based on the frequency of the high-frequency signal from the high-frequency power supply can be a control mode (d1) based on a detected frequency obtained by detecting the frequency of the high-frequency signal input from the high-frequency power supply to the non-reciprocal part, or a control mode (d2) based on a control frequency that controls the frequency of the high-frequency power supply.

[0046] (d1) Control mode based on detected frequency This control mode detects the frequency of a high-frequency signal input from the high-frequency power supply to the non-reciprocal circuit unit, and controls the DC current supplied to the electromagnet based on the detected frequency. This control mode includes a frequency detection unit that detects the frequency of the high-frequency signal between the high-frequency power supply and the reversible circuit unit connected to the input port. The DC power supply control unit controls the DC current based on the frequency detected by the frequency detection unit.

[0047] (d2) Control mode based on control frequency This control mode controls the DC current supplied to the electromagnet based on a control frequency that controls the frequency of the high frequency power supply. This control mode includes a frequency control unit that controls the frequency of the high frequency power supply. The DC power supply control unit controls the DC current based on the control frequency of the frequency control unit.

[0048] (E) Multiple unit configuration The nonreciprocal circuit device of the present invention is configured to include a plurality of units, each unit including a nonreciprocal section, a reversible circuit section, and a DC power supply control section.

[0049] The non-reciprocal part of each unit has frequency characteristics with different center frequencies, and each unit outputs a high frequency signal in a different frequency band.

[0050] The center frequency of the frequency characteristics of each unit is set to be shifted within the frequency band of the high-frequency power supply, and each unit outputs a high-frequency signal in the frequency band set for that unit in accordance with changes in the high-frequency frequency of the high-frequency power supply.By combining the frequency bands set for multiple units in a sequentially shifted manner, the frequency characteristics of the non-reciprocal circuit device can be made broadband.

[0051] (F: Switch output port) The non-reciprocal circuit device of the present invention selects an output port from among a plurality of ports by switching, and outputs a high frequency signal from the selected output port.

[0052] The non-reciprocal circuit device of the present invention can switch the output port in two ways (f1) and (f2).

[0053] (f1) First mode of output port switching In the switching of the output port of the first aspect, the DC power supply control unit switches the current direction of the DC current supplied to the electromagnet. By switching the current direction of the DC current, the direction of the DC magnetic field generated by the electromagnet is switched. By switching the direction of the DC magnetic field, the propagation direction of the electromagnetic wave in the ferrite of the non-reciprocal portion changes, and the output port that outputs the high-frequency signal is switched.

[0054] (f2) Second mode of output port switching In the second aspect of the output port switching, the DC power supply control unit changes the current value as well as the current direction of the DC current, thereby enabling the output port switching and the frequency characteristics to be changed simultaneously.

[0055] For example, when the output mode in which port P2 is the first output port and a high-frequency signal is output is defined as the first mode, and the output mode in which port P3 is the second output port and a high-frequency signal is output is defined as the second mode, and the output port is switched between these two output modes, the first mode outputs a high-frequency signal of frequency f1 from the first output port when switching to the first mode, and the second mode outputs a high-frequency signal of frequency f2 from the second output port when switching to the second mode. Conversely, the frequencies of the high-frequency signals output from the output ports may be swapped, so that the first mode outputs a high-frequency signal of frequency f2 from the first output port when switching to the first mode, and the second mode outputs a high-frequency signal of frequency f1 from the second output port when switching to the second mode. [Effects of the Invention]

[0056] As described above, according to the present invention, the frequency characteristics of a non-reciprocal circuit device can be broadened by reducing the insertion loss of the non-reciprocal circuit device. [Brief explanation of the drawings]

[0057] [Figure 1] 1 is a diagram illustrating a schematic configuration of a non-reciprocal circuit device according to the present invention. [Figure 2] 4A and 4B are diagrams illustrating frequency characteristics of the nonreciprocal circuit device of the present invention. [Figure 3] 1 is a schematic diagram illustrating a first configuration example of a non-reciprocal circuit device according to the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating a second configuration example of a non-reciprocal circuit device according to the present invention. [Figure 5] FIG. 4 is a schematic diagram illustrating a third configuration example of a non-reciprocal circuit device according to the present invention. [Figure 6] FIG. 10 is a schematic diagram illustrating a fourth configuration example of the non-reciprocal circuit device of the present invention. [Figure 7] FIG. 10 is a schematic diagram illustrating a fifth configuration example of a non-reciprocal circuit device according to the present invention. [Figure 8] FIG. 10 is a schematic diagram illustrating a sixth configuration example of a non-reciprocal circuit device according to the present invention. [Figure 9] FIG. 10 is a schematic diagram illustrating a seventh configuration example of a non-reciprocal circuit device according to the present invention. [Figure 10] FIG. 10 is a schematic diagram illustrating the frequency characteristics of a seventh configuration example of the non-reciprocal circuit device of the present invention. [Figure 11] FIG. 1 is a diagram showing the configuration of a three-port lumped constant circulator and an equivalent circuit thereof. [Figure 12] 10A and 10B are diagrams for explaining narrow-band characteristics of a conventional non-reciprocal circuit device. DETAILED DESCRIPTION OF THE INVENTION

[0058] The following describes a schematic configuration of the nonreciprocal circuit device of the present invention with reference to FIGS. 1 and 2, and describes configuration examples 1 to 7 of the nonreciprocal circuit device of the present invention with reference to FIGS.

[0059] Configuration examples 1 to 4 are examples in which the frequency characteristics of the non-reciprocal part are controlled. Configuration example 1 shown in Figure 3 is an example in which DC current is controlled based on the amount of electricity supplied by the high-frequency signal input from the high-frequency power source to the non-reciprocal section, configuration examples 2 and 3 shown in Figures 4 and 5 are examples in which DC current is controlled based on the frequency of the high-frequency signal input from the high-frequency power source to the non-reciprocal section, and configuration example 4 shown in Figure 6 is an example in which the constants of the reversible circuit section are changed based on the frequency of the high-frequency signal input from the high-frequency power source to the non-reciprocal section.

[0060] Configuration Examples 5 to 7 are examples of usage of the non-reciprocal circuit device of the present invention. Configuration example 5 shown in Figure 7 is an example in which the output port is switched by switching the direction of the direct current supplied to the electromagnet, configuration example 6 shown in Figure 8 is an example in which the output port is switched and the frequency of the high-frequency signal to be output is also switched, and configuration example 7 shown in Figures 9 and 10 is an example in which multiple units with different frequency characteristics are provided.

[0061] [Outline of the present invention] The schematic configuration of the non-reciprocal circuit device of the present invention will be described with reference to FIGS. 1 shows an example of a lumped-constant three-port circulator as the non-reciprocal circuit device 1, which outputs a high-frequency signal input to port P1 from a high-frequency power supply 8 to port P2 or port P3. In Fig. 1, the non-reciprocal circuit device 1 includes a non-reciprocal section 6 that transmits signals only in a specific direction and does not transmit signals in the reverse direction.

[0062] The non-reciprocal part 6 includes a ferrite 2, an electromagnet 4 that applies a DC magnetic field to the ferrite 2, and a plurality of conductors 3. In a lumped-parameter three-port circulator, the conductors 3 are three conductors 3a, 3b, and 3c that are arranged so as to cross the ferrite 2 while being insulated from each other, with one end of each conductor connected to the input / output port and the other end grounded.

[0063] The ferrite 2a and the ferrite 2b are arranged on both sides of the conductor 3. The ferrite 2 is not limited to being arranged on both sides of the conductor 3, but may also be arranged on one side of the conductor 3.

[0064] The electromagnet 4 generates a DC magnetic field by a DC current supplied from a DC power supply 7 and applies it to the ferrite 2. A DC power supply control unit 9 is provided between the DC power supply 7 and the electromagnet 4. The DC power supply control unit 9 controls the DC current Idc supplied from the DC power supply 7 to the electromagnet 4, and controls the strength of the DC magnetic field generated by the electromagnet 4.

[0065] The terminals opposite the short-circuit terminal of each conductor 3 (3a, 3b, 3c) of the non-reciprocal section 6 are connected to ports P1 to P3 via reversible circuit sections 5a, 5b, 5c. A high-frequency power supply 8 is connected to port P1, and a high-frequency signal from the high-frequency power supply 8 is supplied to the conductor 3a through the reversible circuit section 5a, generating a high-frequency magnetic field.

[0066] A high-frequency magnetic field generated by the conductor 3a and a DC magnetic field generated by the electromagnet 4 are applied to the ferrite 2 (2a, 2b). The high-frequency magnetic field becomes a positive circularly polarized magnetic field that rotates clockwise toward the direction of the DC magnetic field, and a negative circularly polarized magnetic field that rotates counterclockwise toward the direction of the DC magnetic field. By controlling the strength of the DC magnetic field, the permeability of the positive and non-circularly polarized waves can be controlled, and the direction of propagation of the electromagnetic wave can be set to a predetermined angle. Since the permeability μ of the ferrite changes depending on the frequency f of the high-frequency signal and the magnetic field strength Hdc of the DC magnetic field, the frequency characteristics of the non-reciprocal section 6 shift according to the magnetic field strength Hdc of the DC magnetic field.

[0067] The frequency characteristics shown in FIG. 2(a) are a schematic representation of the pass characteristics when a high-frequency signal passes through the reversible circuit unit 5 and the non-reversible unit 6. In FIG. 2(a), the center frequency fc of the frequency characteristics indicates a case where the magnetic field strength Hdc of the DC magnetic field is a predetermined value. At this time, the frequency f1 of the high-frequency signal coincides with the center frequency fc, and the pass characteristics are good. If the frequency f of the high-frequency signal deviates from the center frequency fc by Δf and changes from f1 to f2 (= fc + Δf), an impedance mismatch occurs in the reversible circuit unit 5 and the non-reversible unit 6. This impedance mismatch causes an insertion loss ΔP, reducing the strength of the high-frequency signal output from the non-reversible unit 6. The frequency characteristics shown in FIG. 2(b) are a schematic representation of the pass characteristics when the frequency f of the high-frequency signal deviates from the center frequency fc.

[0068] Here, when the insertion loss due to impedance mismatch in the reversible circuit unit 5 is expressed as ΔPre and the insertion loss due to impedance mismatch in the non-reciprocal unit 6 is expressed as ΔP, the overall insertion loss ΔP of the reversible circuit unit 5 and the non-reciprocal unit 6 combined is expressed as ΔP = ΔPre + ΔPire, which is the sum of the insertion loss ΔPre of the reversible circuit unit 5 and the insertion loss ΔPire of the non-reciprocal unit 6.

[0069] In FIG. 2(b), the solid line indicates the frequency characteristics before the frequency f of the high-frequency signal is shifted, and the dashed line indicates the frequency characteristics after the frequency f of the high-frequency signal is shifted. Here, the center frequency fc indicates the center frequency of the frequency characteristics after the frequency f of the high-frequency signal is shifted. In the frequency characteristics after the frequency f of the high-frequency signal is shifted, an insertion loss ΔP occurs at the center frequency fc due to impedance mismatch caused by the shift in frequency f, and the output of the high-frequency signal decreases. The insertion loss ΔP is the sum of the insertion loss ΔPre of the reciprocal circuit section 5 and the insertion loss ΔPire of the nonreciprocal section 6. Note that it is assumed here that there is no internal loss in the nonreciprocal circuit device 1.

[0070] The insertion loss ΔPire of the non-reciprocal unit 6 can be compensated for by matching the impedance by matching the center frequency fc of the frequency characteristics of the non-reciprocal unit 6 with the frequency f2 of the high-frequency signal. Also, the insertion loss ΔPre of the reversible circuit unit 5 can be compensated for by matching the impedance by changing the capacitance constant of the reversible circuit unit 5.

[0071] 2(c) shows a state in which the insertion loss ΔP due to impedance mismatching is suppressed by adjusting the frequency characteristics of the non-reciprocal unit 6 and the capacitance of the reversible circuit unit 5. The insertion loss ΔP is suppressed by matching the center frequency fc of the frequency characteristics of the non-reciprocal unit 6 to the frequency f2 of the high-frequency signal to perform impedance matching of the non-reciprocal unit 6 when the frequency characteristics are shifted, and by changing the capacitance constant of the reversible circuit unit 5 to perform impedance matching of the reversible circuit unit 5.

[0072] The DC power supply control unit 9 controls the DC current supplied to the electromagnet 4 to vary the magnetic field strength Hdc of the DC magnetic field applied to the ferrite 2 , thereby controlling the frequency characteristics of the non-reciprocal unit 6 .

[0073] When the frequency of the high frequency signal of the high frequency power supply 8 is varied within the variable frequency range, the magnetic field strength Hdc of the DC magnetic field is controlled to control the frequency characteristics of the non-reciprocal part 6, thereby making it possible to uniformize the strength of the high frequency signal output from the non-reciprocal circuit element 1.

[0074] When the frequency of the high frequency power supply 8 fluctuates around a predetermined frequency, the magnetic field strength Hdc of the DC magnetic field can be controlled to control the frequency characteristics of the non-reciprocal part 6, thereby suppressing fluctuations in the intensity of the high frequency signal output from the non-reciprocal circuit element 1.

[0075] Hereinafter, configuration examples 1 to 7 of the present invention will be described. In configuration examples 1 to 7, the non-reciprocal circuit device 1 is described as having no internal loss.

[0076] [Configuration example 1] A first example of the configuration of the non-reciprocal circuit device of the present invention will be described with reference to FIG. Configuration example 1 is an example in which the DC power supply control unit 9 controls the DC current based on the amount of electricity supplied from the high frequency power supply 8 to the non-reciprocal unit 6. Configuration example 1 includes a power supply detection unit 10 between the high frequency power supply 8 and the reversible circuit unit 5a in the schematic configuration shown in FIG. 1. The power supply detection unit 10 detects the amount of electricity supplied from the high frequency power supply 8 to the non-reciprocal unit 6.

[0077] The voltage, current, and power decrease and the reflectance increase due to insertion loss caused by impedance mismatch in the reversible circuit unit 5 and the non-reciprocal unit 6. The power supply detection unit 10 detects the voltage, current, power, or reflectance that fluctuates due to insertion loss caused by impedance mismatch in the reversible circuit unit 5 and the non-reciprocal unit 6 as the amount of supplied electricity, and feeds this back to the DC power supply control unit 9. Configuration example 1 detects the amount of supplied electricity to detect the amount of change due to reverse loss and forward loss, and feeds back this amount of change to the DC power supply control unit 9.

[0078] The DC power supply control unit 9 controls the DC current supplied from the DC power supply 7 to the electromagnet 4 based on the fed-back amount of electricity, controls the DC magnetic field generated by the electromagnet 4, and controls the frequency characteristics of the non-reciprocal unit 6. The DC power supply control unit 9 compares the detected amount of electricity supplied with a reference value and controls so as to reduce the difference obtained by the comparison. The reference value can be, for example, the amount of electricity supplied when the reverse loss and forward loss are at preset values.

[0079] In configuration example 1, the frequency fRF of the high frequency signal output by the high frequency power supply 8 may be varied by the frequency control unit 11. The frequency control unit 11 controls the frequency fRF of the high frequency signal output by the high frequency power supply 8 within a variable frequency range.

[0080] [Configuration example 2] A second configuration example of the non-reciprocal circuit device of the present invention will be described with reference to FIG. In the second configuration example, the DC power supply control unit 9 controls the DC current based on the frequency fRF of the high frequency signal input from the high frequency power supply 8 to the non-reciprocal unit 6.

[0081] Configuration example 2 includes a frequency detection unit 12 that detects the frequency of the high-frequency signal. The frequency detection unit 12 transmits the detected frequency fRF of the high-frequency signal to the DC power supply control unit 9. The DC power supply control unit 9 controls the DC current supplied from the DC power supply 7 to the electromagnet 4 based on the frequency fRF of the transmitted high-frequency signal, thereby controlling the DC magnetic field generated by the electromagnet 4.

[0082] The DC power supply control unit 9 determines in advance the relationship between the center frequency fc and the DC current Idc within the variable frequency range. The DC power supply control unit 9 sets the frequency fRF of the detected radio frequency signal as the center frequency fc of the frequency characteristics of the non-reciprocal unit 6, calculates the DC current Idc from the center frequency fc corresponding to the frequency fRF of the detected radio frequency signal based on the predetermined relationship between the center frequency fc and the DC current Idc, and supplies the calculated DC current Idc to the electromagnet 4 to control the DC magnetic field and thereby control the frequency characteristics of the non-reciprocal unit 6.

[0083] In configuration example 2, similarly to configuration example 1, the frequency fRF of the high frequency signal output by the high frequency power supply 8 may be varied by the frequency control unit 11. The frequency control unit 11 controls the frequency fRF of the high frequency signal output by the high frequency power supply 8 within a variable frequency range.

[0084] [Configuration example 3] A third configuration example of the non-reciprocal circuit device of the present invention will be described with reference to FIG. Similar to configuration example 2, configuration example 3 is an example in which the DC power supply control unit 9 controls the DC current based on the frequency fRF of the radio frequency signal input from the radio frequency power supply 8 to the non-reciprocal unit 6. While configuration example 2 is configured to obtain the frequency fRF of the radio frequency signal from the detection signal detected by the frequency detection unit 12, configuration example 3 is configured to obtain the frequency fRF of the radio frequency signal from the frequency control unit 11 that controls the frequency fRF of the radio frequency signal output from the radio frequency power supply 8.

[0085] Configuration example 3 includes a frequency control unit 11, which controls the frequency fRF of the high frequency signal output by the high frequency power supply 8. The frequency control unit 11 transmits the frequency fRF of the high frequency signal to the DC power supply control unit 9. The DC power supply control unit 9 controls the DC current supplied from the DC power supply 7 to the electromagnet 4 based on the frequency fRF of the transmitted high frequency signal, controls the DC magnetic field generated by the electromagnet 4, and controls the frequency characteristics of the non-reciprocal unit 6.

[0086] As in configuration example 2, the DC power supply control unit 9 determines in advance the relationship between the center frequency fc and the DC current Idc within the variable frequency range. The DC power supply control unit 9 sets the frequency fRF of the detected radio frequency signal as the center frequency fc of the frequency characteristics of the non-reciprocal unit 6, and determines the DC current Idc from the center frequency fc corresponding to the frequency fRF of the detected radio frequency signal based on the predetermined relationship between the center frequency fc and the DC current Idc. The determined DC current Idc is supplied to the electromagnet 4 to generate a DC magnetic field.

[0087] [Configuration example 4] A fourth configuration example of the non-reciprocal circuit device of the present invention will be described with reference to FIG. Like configuration example 1, configuration example 4 includes a control system that controls the DC current by feeding back the amount of power supply electricity detected by the power supply detection unit 10 to the DC power supply control unit 9, controls the DC magnetic field generated by the electromagnet 4 based on the DC current Idc obtained by controlling the DC current, and controls the frequency characteristics of the non-reciprocal unit 6.

[0088] Configuration example 4 includes a control system that controls the frequency characteristics of the non-reciprocal unit 6 by controlling the DC current using the DC power supply control unit 9, as well as a control system that controls the frequency characteristics of the non-reciprocal unit 6 by changing the capacitance constant of the capacitor provided in the reversible circuit unit 5a.

[0089] Configuration example 4 includes a constant changing unit 13 that changes the capacitance constant Cp of the capacitor included in the reversible circuit unit 5a. The constant changing unit 13 acquires the frequency fRF of the high-frequency signal from the frequency control unit 11, calculates the capacitance constant Cp based on the relationship in equation (2), and changes the capacitance constant of the reversible circuit unit 5a based on the calculated constant Cp. This allows the reversible circuit unit 5a to match the center frequency fc of the frequency characteristics of the non-reversible unit 6 to the frequency fRF of the high-frequency signal from the high-frequency power supply 8.

[0090] [Configuration example 5] A fifth configuration example of the non-reciprocal circuit device of the present invention will be described with reference to FIG. Configuration example 5 is a configuration example in which the output port of the non-reciprocal unit 6 is switched. The output port can be switched in any of configuration examples 1 to 4, but the following description will be given taking configuration example 1 as an example.

[0091] The output port of the non-reciprocal unit 6 is switched by reversing the direction of the DC magnetic field generated by switching the current direction of the DC current Idc supplied to the electromagnet 4. The current direction of the DC current Idc is switched by the control unit 14 controlling the DC power supply control unit 9. Fig. 7(a) shows the case where port P2 is switched to the output port, and Fig. 7(b) shows the case where port P3 is switched to the output port.

[0092] [Configuration example 6] A sixth configuration example of the non-reciprocal circuit device of the present invention will be described with reference to FIG. Configuration example 6 is a configuration example in which the output port of the non-reciprocal unit 6 is switched as in configuration example 5, and simultaneously with the switching, the frequency of the high frequency signal output from the output port is switched.

[0093] The output port of the non-reciprocal unit 6 is switched and the frequency is switched by switching the current direction of the DC current Idc supplied to the electromagnet 4 and simultaneously switching the frequency of the high frequency frequency output by the high frequency power supply 8.

[0094] The sixth configuration example includes a control unit 14, which performs current direction control for switching the current direction of the direct current Idc and frequency control for switching the frequency of the high frequency signal output by the high frequency power supply 8.

[0095] The control unit 14 controls the DC power supply control unit 9 to switch the direction of the DC current Idc, thereby reversing the direction of the DC magnetic field generated. The control unit 14 also controls the high frequency power supply 8 to switch the frequency of the high frequency signal.

[0096] Figure 8(a) shows the case where port P2 is switched to the output port and a high-frequency signal with frequency f1 is output from port P2, and Figure 8(b) shows the case where port P3 is switched to the output port and a high-frequency signal with frequency f2 is output from port P3. The frequencies f1 and f2 of the high-frequency signals output from ports P2 and P3 can be set arbitrarily within the variable frequency range of the high-frequency power supply.

[0097] [Configuration Example 7] A seventh example of the configuration of the non-reciprocal circuit device of the present invention will be described with reference to FIGS. Configuration example 7 includes a plurality of units with different frequency characteristics, and outputs a high-frequency signal from a non-reciprocal circuit element of a unit having frequency characteristics suitable for the frequency of a high-frequency signal input from a high-frequency power source.

[0098] The variable frequency range of the frequency characteristics obtained by changing the DC magnetic field is limited, and if the variable frequency range of the high frequency power supply is wide, it is difficult to cover the entire variable frequency range with a single non-reciprocal circuit element. Configuration Example 7 uses multiple units with frequency characteristics that separate different frequency ranges, and by separating high frequency signals of different frequency ranges using each unit, it is possible to separate signals over the entire variable frequency range of the high frequency power supply.

[0099] Each unit 20 includes a non-reciprocal section 6, a reversible circuit section 5, and a DC power supply control section 9. Configuration example 7 shows a configuration including three units 20A, 20B, and 20C as the multiple units 20.

[0100] The reversible circuit section 5 included in each unit 20A, 20B, and 20C has constants set to correspond to the respective frequency ranges. The non-reversible section 6 of each unit 20A, 20B, and 20C shifts the frequency characteristics of the center frequency determined by the reversible circuit section 5 by controlling the DC magnetic field of the electromagnet 4, thereby widening the frequency range to be separated.

[0101] By shifting the frequency ranges separated by each of the units 20A, 20B, and 20C, the total frequency range of the non-reciprocal circuit device becomes the combination of the frequency ranges of each unit, making it possible to achieve a wide frequency range.

[0102] Fig. 10 schematically shows the frequency characteristics of the non-reciprocal circuit device according to Configuration Example 7 configured with multiple units. Fig. 10 shows an example in which the overall frequency bandwidth BW of the non-reciprocal circuit device is configured by combining three frequency bandwidths: frequency bandwidth BW1, frequency bandwidth BW2, and frequency bandwidth BW3. In this configuration example, the frequency characteristics of unit 20A, unit 20B, and unit 20C are set with frequencies fc1, fc2, and fc3 as center frequencies, respectively, and frequency bandwidths BW1, BW2, and BW3 are set.

[0103] 10(a) shows a frequency width BW1 obtained by shifting the frequency characteristics with the frequency fc1 as the center frequency by varying the DC magnetic field of the electromagnet in the unit 20A. The frequency width BW1 is set by shifting the frequency characteristics.

[0104] FIG. 10(b) shows the frequency width BW2 of the frequency characteristics of the unit 20B with the frequency fc2 as the center frequency, and FIG. 10(c) shows the frequency width BW3 of the frequency characteristics of the unit 20C with the frequency fc3 as the center frequency.

[0105] The frequency width by which the frequency characteristics are shifted can be set based on the relationship between the change width of the DC magnetic field of the electromagnet and the change width of the frequency characteristics, and can be set by the change width of the frequency characteristics that can be changed by changing the DC magnetic field of the electromagnet.

[0106] FIG. 10(d) shows a state in which the overall frequency bandwidth BW of the non-reciprocal circuit device is formed by combining the frequency widths BW1, BW2, and BW3 of the units 20A, 20B, and 20C.

[0107] According to configuration example 7, even if the frequency bandwidth of the frequency characteristics that can be adjusted by each unit is narrow, by combining multiple units having frequency characteristics with different center frequencies, the overall frequency bandwidth BW of the non-reciprocal circuit device can be widened, thereby achieving a broadband.

[0108] In each configuration example, the reverse loss (isolation), which is the power loss caused by reflections that occur at the output port of the circulator, can be detected by adding power supply detection units to ports P2 and P3 in addition to the power supply detection unit installed at port P1.

[0109] When the circulator transmits high-frequency current from port P1 to the load at port P2, from the load at port P2 to the load at port P3, and from the load at port P3 to port P1, the power supply detection unit provided at port P2 detects the amount of electricity reflected from the load connected to the output of the circulator, and the power supply detection unit provided at port P3 detects the amount of electricity reflected from the load and input to the circulator.

[0110] The reverse loss is obtained by adding up the electrical quantities detected by these power supply detectors. By feeding back the detected electrical quantities to the DC power supply controller, it becomes possible to apply control to reduce the reverse loss.

[0111] It should be noted that the description of the above embodiments and modifications is merely an example of a non-reciprocal circuit element according to the present invention, and the present invention is not limited to the respective embodiments. Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention. [Industrial Applicability]

[0112] The non-reciprocal circuit device of the present invention can be applied to a power source (RF generator) that outputs high frequency waves and is used in, for example, semiconductor manufacturing equipment, liquid crystal panel manufacturing equipment, and the like. [Explanation of symbols]

[0113] 1. Non-reciprocal circuit elements 2, 2a, 2b Ferrite 3, 3a, 3b, 3c conductor 4. Electromagnets 5, 5a, 5b, 5c Reversible circuit section 6 Irreversible part 7 DC power supply 8 High frequency power supply 9 DC power supply control section 10 Power supply detection unit 11 Frequency control section 12 Frequency detection section 13 Constant change section 14 Control Unit 20, 20A, 20B, 20C units 100 Ideal Circulator 101 Lumped constant circulator 102 Ferrite 103, 103a, 103b, 103c conductors 104, 104a, 104b permanent magnets 105, 105a, 105b, 105c capacitors 106, 106a, 106b, 106c parallel resonant circuit BW Frequency Bandwidth BW1, BW1, BW2 frequency width Cp capacitance constant Hdc DC magnetic field strength Idc direct current Lp inductor P1, P2, P3 ports ΔP insertion loss ΔPre insertion loss ΔPire insertion loss ΔPs Insertion loss fc, fc1, fc2, fc3 center frequency η irreversibility index

Claims

1. a non-reciprocal section including a ferrite, an electromagnet that applies a DC magnetic field to the ferrite, and a plurality of conductors that are arranged to cross the ferrite in an insulated state and have a plurality of short-circuited ends; a reversible circuit section connected between the other ends of the conductors and an input / output port, for varying the resonant frequency of a parallel resonant circuit formed by the inductance of the conductor of the non-reversible section and the capacitor of the reversible circuit section; a DC power supply control unit that controls a DC current supplied to the electromagnet based on a high frequency signal input from a high frequency power supply to the non-reciprocal unit; Equipped with the DC power supply control unit controls the DC current supplied to the electromagnet to vary the intensity of the DC magnetic field applied to the ferrite, thereby controlling the frequency characteristics of the non-reciprocal unit. Non-reciprocal circuit element.

2. the DC power supply control unit controls the current value of the DC current based on the amount of electricity supplied by the high-frequency signal input from the high-frequency power supply to the non-reciprocal unit to vary the intensity of the DC magnetic field, and aligns the center frequency of the frequency characteristics of the non-reciprocal unit with the frequency of the high-frequency signal from the high-frequency power supply. The non-reciprocal circuit device according to claim 1 .

3. a power supply detection unit for detecting the amount of supplied electricity is provided between the high frequency power source and a reversible circuit unit connected to the input port; The amount of electricity supplied is any one of voltage, current, power, and reflectance; The non-reciprocal circuit device according to claim 2 .

4. the DC power supply control unit controls the DC current based on the frequency of a high-frequency signal input from a high-frequency power supply to the non-reciprocal unit to vary the intensity of the DC magnetic field, thereby adjusting the center frequency of the frequency characteristics of the non-reciprocal unit to match the high-frequency signal of the high-frequency power supply; The non-reciprocal circuit device according to claim 1 .

5. a frequency detection unit for detecting a frequency of the high frequency signal is provided between the high frequency power supply and a reversible circuit unit connected to an input port; the DC power supply control unit controls the DC current based on the frequency detected by the frequency detection unit. The non-reciprocal circuit device according to claim 4.

6. a frequency control unit for controlling the frequency of the high frequency power supply, the DC power supply control unit controls the DC current based on the control frequency of the frequency control unit. The non-reciprocal circuit device according to claim 4.

7. the reversible circuit unit includes a capacitor that forms a parallel resonant circuit together with the inductance of the conductor; The non-reciprocal circuit device according to claim 1 .

8. a constant changing unit that changes the capacitance of the capacitor of the reversible circuit unit; the constant changing unit changes the capacitance of the capacitor of the reversible circuit unit based on the frequency of the high-frequency signal of the high-frequency power supply, changing the resonant frequency of the parallel resonant circuit by changing the capacitance; By changing the frequency of the resonant frequency, the non-reciprocal portion (a) Changing the frequency characteristics to match the center frequency with the frequency of the high-frequency signal of the high-frequency power source; and (b) Impedance matching for matching the impedance of input and output ports To do The non-reciprocal circuit device according to claim 7.

9. a plurality of units each including the non-reciprocal unit, the reciprocal circuit unit, and the DC power supply control unit; The non-reciprocal parts of the units have frequency characteristics with different center frequencies, and each unit outputs a high-frequency signal in a different frequency band.

9. The non-reciprocal circuit device according to claim 1.

10. the DC power supply control unit switches the current direction of the DC current supplied to the electromagnet, thereby switching the output port from which the non-reciprocal unit outputs the high-frequency signal.

10. The non-reciprocal circuit device according to claim 1.

11. the DC power supply control unit changes the current value along with switching the current direction of the DC current; Switching output ports and changing frequency characteristics. The non-reciprocal circuit device according to claim 10.

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