JP2021190907A - Hybrid ring circuit - Google Patents

Abstract

To improve electrical characteristics in a pass frequency band.SOLUTION: A first hybrid ring and a second hybrid ring are coupled with each other. Series resonance circuits each of which resonates at Fo respectively couple between each of first and second terminals P1 and P2 and the first hybrid ring, between each of third and fourth terminals P3 and P4 and the second hybrid ring, and between the first hybrid ring and the second hybrid ring. The series resonance circuits compensate impedance characteristics of the first hybrid ring and the second hybrid ring, and thereby, electrical characteristics in a pass frequency band whose center frequency is Fo are improved.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hybrid ring circuit capable of widening a wide band.

A conventional hybrid ring circuit is disclosed in Patent Document 1, and the circuit configuration of the conventional principle hybrid ring circuit is shown in FIG. The hybrid ring circuit 100 shown in FIG. 21 is used for distribution and synthesis of high frequencies, and when the wavelength of the center frequency Fo used is λo, the four distributed constant lines D101, each having an electric length of λo / 4, D102, D103, and D104 are connected in a ring shape. In the hybrid ring circuit 100 having an electric length of λo around the circumference, the connection point between D101 and D104 is the first terminal P101, the connection point between D101 and D102 is the second terminal P102, and the connection point between D102 and D103 is the third terminal. The connection point between the terminals P103, D103 and D104 is the fourth terminal P104. The characteristic impedances of the distributed constant lines D101, D102, D103, and D104 are W12, W23, W34, and W14, and the impedance connected with the first terminal P101 and the second terminal P102 as input terminals, that is, the input impedance is Za. The impedance connected with the 3rd terminal P103 and the 4th terminal P104 as the output terminal, that is, the output impedance is Zb. Then, when the second terminal P102 is terminated by Za and the power "1" is applied from the first terminal P101, the power ratio that appears in the fourth terminal P104 facing the first terminal P101 is N, and the diagonal of the first terminal P101. If the power ratio appearing at the third terminal P103 of is defined as (1-N), the characteristic impedances W12, W34, W14, and W23 of the distributed constant lines D101, D102, D103, and D104 are as follows (1) to (4). ) Is expressed. However, 1> N ≧ 0.5. In the following description, N is referred to as distribution ratio.
W12 = Za√ {N / (1-N)} (1)
W34 = Zb√ {N / (1-N)} (2)
W14 = √ (Za × Zb × N) (3)
W23 = √ (Za × Zb × N) (4)

In the circuit of FIG. 21, the phase between the terminals in Fo when the first terminal P101 is used as a reference is −90 ° with respect to the fourth terminal P104 on the opposite side corresponding to the passing terminal, and the pair corresponding to the coupling terminal. It is −180 ° with respect to the third terminal P103 in the angular direction. Further, no electric power appears at the terminated second terminal P102, and the terminal becomes an isolation terminal. Even in the phase when the reference terminal is other than the first terminal P101, it is -90 ° for the terminal on the opposite side of the reference input terminal and -180 ° for the diagonal terminal, and the remaining terminals are. It becomes an isolation terminal. The hybrid ring is characterized in that the electric power output to the terminals diagonally opposite to the opposite side when viewed from the input terminal has a relative phase difference of 90 °.

In the hybrid ring circuit 100, Za = Zb = Zo, and N = 0.5 when the hybrid ring circuit is set to be evenly distributed. Here, when the characteristic impedances W12, W34, W14, and W23 of the four distributed constant lines D101, D102, D103, and D104 when Zo = 50Ω are obtained from the equations (1) to (4), W12 = W34 = It is determined to be 50Ω, and W14 = W23≈35.355339Ω. In the hybrid ring circuit 100, the electrical characteristics when the characteristic impedances W12, W34, W14, and W23 are set to the above values and Fo is set to 150 MHz are shown in FIGS. 22 to 24. FIG. 22 is a diagram showing insertion loss characteristics and coupling loss characteristics between P101 and P104 terminals, FIG. 23 is a diagram showing isolation characteristics between P101 and P102 terminals, and FIG. 24 is a diagram showing relative phase deviation characteristics. Is.
In FIG. 22, the frequency characteristic of the insertion loss between the P101 and P104 terminals is shown by the solid line, and the frequency characteristic of the coupling loss between the P101 and P103 terminals is shown by the broken line, and the frequency range is 100 to 200 MHz. .. With reference to FIG. 22, it can be seen that the insertion loss and the coupling loss are evenly distributed at about 3 dB in Fo. Further, referring to FIG. 23, the frequency range is 100 to 200 MHz, the isolation between the P101 and P102 terminals is the maximum in Fo, and the frequency range in which 20 dB of isolation is obtained is about 142 to about 158 MHz. You can see that. Further, FIG. 24 shows the frequency characteristics of the relative phase deviation obtained by subtracting the phase between the P101 and P104 terminals from the phase between the P101 and P103 terminals, and the frequency range is 100 to 200 MHz. With reference to FIG. 24, it can be seen that a phase of approximately −90 ° is obtained in the frequency range of about 142 to about 158 MHz.

For the purpose of widening the bandwidth of the hybrid ring circuit 100 shown in FIG. 21, a hybrid ring circuit in which two hybrid ring circuits 100 shown in FIG. 21 are connected has been proposed. FIG. 25 shows the circuit configuration of the two-connected hybrid ring circuit 110.
The hybrid ring circuit 110 shown in FIG. 25 is configured by substantially connecting two hybrid ring circuits 100 shown in FIG. 21, and has four distributed constant lines D111 and D112 having an electric length of λo / 4, respectively. , D113, D114 are connected in a ring shape, and four distributed constant lines D113, D115, D116, D117 having an electric length of λo / 4, respectively, are connected in a ring shape. They are connected in a columnar sequence. In the two-connected hybrid ring circuit 110, the connection point between D111 and D114 is the first terminal P111, the connection point between D111 and D112 is the second terminal P112, and the connection point between D115 and D116 is the third terminal P113. The connection point between D116 and D117 is the fourth terminal P114. The opposite side of the first terminal P111 is the fourth terminal P114, and the diagonal direction of the first terminal P111 is the third terminal P113.
Here, when the hybrid ring circuit 110 is set to even distribution, the characteristic impedance of the distributed constant line D111 connected between the first terminal P111 and the second terminal P112, and the third terminal P113 and the fourth terminal P114 The characteristic impedance with the distributed constant line D116 connected between the two is equal to that of Z1. Further, the characteristic impedances of the two distributed constant lines D114 and D117 connected longitudinally between the first terminal P111 and the fourth terminal P114 are equally Z2, and are between the second terminal P112 and the third terminal P113. The characteristic impedances of the two distributed constant lines D112 and D115 connected in series are also Z2. Further, the characteristic impedance of the distributed constant line D113 connected between the connection point with the distributed constant lines D112 and D115 and the connection point with the distributed constant lines D114 and D117 is Z2'.

FIG. 29 shows a hybrid ring circuit 120 obtained by disassembling the two connected hybrid ring circuits 110 shown in FIG. 25 in order to obtain the characteristic impedances Z1, Z2, Z2'of the distributed constant lines D111 to D117 of the hybrid ring circuit 110.
The hybrid ring circuit 120 shown in FIG. 29 includes a first hybrid ring in which four distributed constant lines D111, D112, D113', and D114 having an electric length of λo / 4 are connected in a ring shape, and λo /, respectively. A second hybrid ring in which four distributed constant lines D113', D115, D116, and D117 having an electric length of 4 are connected in a ring shape is connected in a two-stage longitudinal manner. In the hybrid ring circuit 120, the connection point a between D111 and D114 is the first terminal P111, the connection point between D111 and D112 is the second terminal P112, and the connection point e between D115 and D116 is the third terminals P113 and D116. The connection point c with D117 is set to the fourth terminal P114. Further, let b be the connection point between D114 of the first hybrid ring and D117 of the second hybrid ring, and d be the connection point between D112 of the first hybrid ring and D115 of the second hybrid ring. The opposite side of the first terminal P111 is the fourth terminal P114, and the diagonal direction of the first terminal P111 is the third terminal P113.

Here, when the hybrid ring circuit 120 is set to even distribution, the characteristic impedance of the distributed constant line D111 of the first hybrid ring and the characteristic impedance of the distributed constant line D116 of the second hybrid ring become equal to each other and become Z1. Further, the characteristic impedances of D114 of the first hybrid ring and D117 of the second hybrid ring are equal to Z2, and the characteristic impedances of D112 of the first hybrid ring and D115 of the second hybrid ring are also equal to Z2. Further, the characteristic impedances of D113'of the first hybrid ring and D113' of the second hybrid ring are equal to Z3.

In the hybrid ring circuit 120, there are four transmission paths between the input / output terminals, and the transmission amount and the phase delay amount of each are obtained. Here, in the hybrid ring circuit 120, the input impedance is Zo with the first terminal P111 and the second terminal P112 as input terminals, and the output impedance is Zo with the third terminal P113 and the fourth terminal P114 as output terminals. Then, the second terminal P112 is terminated by Zo, and the distribution ratios of the first hybrid ring and the second hybrid ring are set to N, respectively.
Then, in the opposite path from the connection point a to the connection point c, the first path of the connection point a → the connection point b → the connection point c and the second path of the connection point a → the connection point d → the connection point c be. In the first path, the distribution ratio of the first hybrid ring from the connection point a to the connection point b is N, the phase delay amount is −90 °, and the distribution ratio of the second hybrid ring from the connection point b to the connection point c is. since the phase delay amount becomes -90 ° with N, the distribution ratio of the first path phase delay amount becomes -180 ° with N ^2. Further, in the second path, the distribution ratio of the first hybrid ring from the connection point a to the connection point d is (1-N), the phase delay amount is −180 °, and the second path from the connection point d to the connection point c. Since the distribution ratio of the hybrid ring is (1-N) and the phase delay amount is −180 °, the distribution ratio of the first path is (1-N) ² and the phase delay amount is -360 °.

Further, in the diagonal path from the connection point a to the connection point e, the third path of the connection point a → the connection point b → the connection point e and the fourth path of the connection point a → the connection point d → the connection point e. There is. In the third path, the distribution ratio of the first hybrid ring from the connection point a to the connection point b is N, the phase delay amount is −90 °, and the distribution ratio of the second hybrid ring from the connection point b to the connection point e is. Since the phase delay amount is −180 ° in (1-N), the distribution ratio of the third path is N (1-N) and the phase delay amount is -270 °. Further, in the fourth path, the distribution ratio of the first hybrid ring from the connection point a to the connection point d is (1-N), the phase delay amount is −180 °, and the second path from the connection point d to the connection point e. Since the distribution ratio of the hybrid ring is N and the phase delay amount is −90 °, the distribution ratio of the fourth path is N (1-N) and the phase delay amount is -270 °.
When the combined voltage ratio in the opposite path and the combined voltage ratio in the diagonal path are obtained and N is obtained from the obtained combined voltage ratio,
N = (2 + √2) / 4 (5)
It can be seen that the first hybrid ring and the second hybrid ring are unequally distributed hybrid rings.
That is, by connecting the first hybrid ring and the second hybrid ring of the unequal distribution of the distribution ratio N represented by the equation (5) in cascade, the hybrid ring circuit 120 of equal distribution can be obtained.

Next, let Zk be the impedance of the connection point b and the connection point d.
Zk = Zoo / (1 + √0.5) (6)
I will try it. Then, the characteristic impedances Z1, Z2, Z3 of the distributed constant lines D111 to D117 of the hybrid ring circuit 120 are obtained from the above equations (1) to (4). In this case, Z1 = W12, Z2 = W23 = W14, and Z3 = W34 are replaced, and N is represented by the above equation (5). When you ask for Z1,
Z1 = W12 = Zo√ {N / (1-N)} = (1 + √2) Zo (7)
Is required. Also, if you ask for Z3,
Z3 = W34 = Zk√ {N / (1-N)} = (1 + √2) Zk = Zo√2 (8)
Is required. Furthermore, when Z2 is obtained,
Z2 = W14 = W23 = √ (Zo × Zk × N) = Zoo / √2 (9)
Is required. Since Z2'in the hybrid ring circuit 110 is connected in parallel with Z3,
Z2'= Z3 / 2 (10)
Will be.

Here, in the hybrid ring circuit 110, when the characteristic impedances Z1, Z2, Z2'when Zo = 50Ω are obtained from the above equations (7) to (10), Z1≈120.711Ω is determined, and Z2≈ It is determined to be 35.355Ω, and Z2'is equal to Z2 and is determined to be Z2≈35.355Ω. In the hybrid ring circuit 110, the electrical characteristics when the characteristic impedances Z1, Z2, Z2'are set to the above values and Fo is set to 150 MHz are shown in FIGS. 26 to 28. FIG. 26 is a diagram showing insertion loss characteristics and coupling loss characteristics between P111 and P114 terminals, FIG. 27 is a diagram showing isolation characteristics between P111 and P112 terminals, and FIG. 28 is a diagram showing relative phase deviation characteristics. Is.
In FIG. 26, the solid line shows the frequency characteristic of the insertion loss between the P111 and P114 terminals, and the broken line shows the frequency characteristic of the coupling loss between the P101 and P113 terminals, and the frequency range is 100 to 200 MHz. .. With reference to FIG. 26, it can be seen that the insertion loss and the coupling loss are evenly distributed at about 3 dB in Fo. Further, referring to FIG. 27, the frequency range is 100 to 200 MHz, the maximum value of the isolation between the P111 and P112 terminals is obtained in Fo, and the frequency range in which the isolation of 25 dB is obtained is about 132 to about 167 MHz. It can be seen that the band is wider than the hybrid ring circuit 100. Further, FIG. 28 shows the frequency characteristics of the relative phase deviation obtained by subtracting the phase between the P111 and P114 terminals from the phase between the P111 and P113 terminals, and the frequency range is 100 to 200 MHz. With reference to FIG. 28, it can be seen that a phase of approximately −90 ° is obtained in the frequency range of about 132 to about 167 MHz. As described above, it can be seen that the hybrid ring circuit 110 has a wider band than the hybrid ring circuit 100.

Japanese Unexamined Patent Publication No. 2000-101312

In the conventional wideband hybrid ring circuit 110, in the frequency characteristics of the isolation shown in FIG. 27, about 132 MHz to about 167 MHz at which the isolation is 25 dB or more is set as an effective passing frequency band. Then, when the maximum value of the distribution deviation between terminals, which is the difference between the insertion loss between the P111 and P114 terminals and the coupling loss between the P111 and P113 terminals in the band of about 132 MHz to about 167 MHz, is read with reference to FIG. 26, it is about 0. It becomes .5 dB. Further, when the maximum in-band amplitude deviation of the coupling loss between the P111 and P113 terminals is read with reference to FIG. 26, it is about 0.5 dB, and there is a problem that the ideal 0 dB without deviation is not obtained. rice field.
Therefore, an object of the present invention is to provide a hybrid ring circuit capable of improving the electrical characteristics in the passing frequency band.

In order to achieve the above object, in the hybrid ring circuit of the present invention, when the center frequency used is Fo and the wavelength of Fo is λo, the first is four distributed constant lines having an electric length of λo / 4, respectively. The first hybrid ring, which is connected at the connection point or the fourth connection point to form a ring, and four distributed constant lines having an electric length of λo / 4, respectively, are connected at the fifth connection point to the eighth connection point. A second hybrid ring that is formed into a ring shape and is connected to the first hybrid ring, and a first series resonant circuit that resonates with Fo that connects the first terminal and the first connection point of the first hybrid ring. , A second series resonant circuit that resonates at Fo that connects the second terminal and the second connection point of the first hybrid ring, and the third connection point of the first hybrid ring and the sixth connection of the second hybrid ring. A third series resonant circuit that resonates with Fo that connects points, and a fourth series resonant circuit that resonates with Fo that couples the fourth connection point of the first hybrid ring and the fifth connection point of the second hybrid ring. And a fifth series resonant circuit that resonates at Fo connecting the seventh connection point of the second hybrid ring and the third terminal, and Fo connecting the eighth connection point and the fourth terminal of the second hybrid ring. The first hybrid ring and the second hybrid are provided by the first series resonant circuit or the sixth series resonant circuit, which is provided with a sixth series resonant circuit that resonates with the above and is configured by connecting an inductance and a capacitance in series. The most important feature is that the impedance characteristics of the ring are compensated and the electrical characteristics in the passing frequency band centered on Fo are improved.

In the hybrid ring circuit of the present invention, the values of the inductance and the capacitance constituting the first series resonance circuit or the sixth series resonance circuit are predetermined at frequencies lower than Fo and at the lowest frequency. It is a value at which isolation can be obtained.
Further, in the hybrid ring circuit of the present invention, when the impedance of the first terminal to the fourth terminal is set to Zoo, the first series resonance circuit, the second series resonance circuit, the fifth series resonance circuit, and the above. The capacitance value in the sixth series resonant circuit is A / (Fo · Zo), the capacitance value in the third series resonant circuit and the fourth series resonant circuit is B (Fo · Zo), and the first. The value of the inductance in the series resonant circuit, the second series resonant circuit, the fifth series resonant circuit, and the sixth series resonant circuit is (C · Zo) / Fo, and the third serial resonant circuit and the fourth series are The value of the inductance in the resonant circuit is normalized to (D · Zo) / Fo, and the constant A or the constant D becomes a value corresponding to the value of the predetermined isolation to be obtained.
Further, in the hybrid ring circuit of the present invention, the distributed constant line having the electric length of λo / 4 constituting the first hybrid ring and the second hybrid ring is separated from the inductance and the capacitance of the lumped constant. It can be configured by a low frequency pass type 90 ° phase circuit.
Further, in the hybrid ring circuit of the present invention, when n is an integer of 2 or more, a unit phase circuit having a phase of 90 ° / n can be connected in n stages to form the 90 ° phase circuit.

In the present invention, the first terminal or the fourth terminal and the hybrid ring connected in two are coupled by a series resonance circuit that resonates with Fo, and the hybrid rings are coupled by a series resonance circuit that resonates with Fo and connected in two. As a result, the electrical characteristics in the passing frequency band are improved and the band is widened.

It is a circuit diagram which shows the structure of the hybrid ring circuit of 1st Embodiment of this invention. It is a figure which shows the frequency characteristic of the insertion loss and the coupling loss of the hybrid ring circuit of 1st Embodiment of this invention. It is a figure which shows the frequency characteristic of the return loss of the hybrid ring circuit of 1st Embodiment of this invention. It is a figure which shows the frequency characteristic of the isolation of the hybrid ring circuit of 1st Embodiment of this invention. It is a figure which shows the frequency characteristic of the phase of the hybrid ring circuit of 1st Embodiment of this invention. It is a figure which shows the frequency characteristic of another phase of the hybrid ring circuit of 1st Embodiment of this invention. It is a figure which shows the frequency characteristic of the phase difference of the hybrid ring circuit of 1st Embodiment of this invention. It is a circuit diagram which shows the other structure of the hybrid ring circuit for demonstrating the circuit constant of the hybrid ring circuit which concerns on this invention. It is a figure which shows the electrical characteristic with respect to the circuit constant of the hybrid ring circuit shown in FIG. It is a figure which shows the frequency characteristic which contrasts with the example of the frequency characteristic of the isolation of the hybrid ring circuit shown in FIG. It is a circuit diagram which shows the other structure of the hybrid ring circuit for demonstrating the circuit constant of the hybrid ring circuit which concerns on this invention. It is a figure which shows the frequency characteristic which contrasts with the example of the frequency characteristic of the isolation of the hybrid ring circuit shown in FIG. It is a circuit diagram of a 90 ° phase circuit as a lumped constant circuit. It is a circuit diagram which shows the structure of the hybrid ring circuit of 2nd Embodiment of this invention. It is a figure which shows the frequency characteristic of the insertion loss and the coupling loss of the hybrid ring circuit of the 2nd Embodiment of this invention. It is a figure which shows the frequency characteristic of the return loss of the hybrid ring circuit of 2nd Embodiment of this invention. It is a figure which shows the frequency characteristic of the isolation of the hybrid ring circuit of 2nd Embodiment of this invention. It is a figure which shows the frequency characteristic of the phase of the hybrid ring circuit of 2nd Embodiment of this invention. It is a figure which shows the frequency characteristic of another phase of the hybrid ring circuit of 2nd Embodiment of this invention. It is a figure which shows the frequency characteristic of the phase difference of the hybrid ring circuit of 2nd Embodiment of this invention. It is a circuit diagram which shows the structure of the conventional hybrid ring circuit. It is a figure which shows the frequency characteristic of the insertion loss and the coupling loss of the conventional hybrid ring circuit. It is a figure which shows the frequency characteristic of the isolation of the conventional hybrid ring circuit. It is a figure which shows the frequency characteristic of the phase difference of the conventional hybrid ring circuit. It is a circuit diagram which shows the structure of another conventional hybrid ring circuit. It is a figure which shows the frequency characteristic of the insertion loss and the coupling loss of other conventional hybrid ring circuits. It is a figure which shows the frequency characteristic of the isolation of the other conventional hybrid ring circuit. It is a figure which shows the frequency characteristic of the phase difference of the other conventional hybrid ring circuit. It is a circuit diagram which shows the structure of the hybrid ring circuit which disassembled the other conventional hybrid ring circuit.

<First Example>
FIG. 1 shows a circuit diagram showing the configuration of the hybrid ring circuit according to the first embodiment of the present invention.
The hybrid ring circuit 1 of the first embodiment shown in FIG. 1 is used for distribution and synthesis of high frequencies, and when the wavelength of the center frequency Fo used is λo, the electric length of each of the four is λo / 4. Distributed constant line D1, D2, D3, D4 are connected in a ring shape to form a first hybrid ring having an electric length of λo, and four distributed constant lines having an electric length of λo / 4, respectively. D5, D6, D7, and D8 are connected in a ring shape, and a second hybrid ring having an electric length of λo is connected in a two-stage longitudinal manner. Further, the first series in which the first terminal P1 of the hybrid ring circuit 1 of the first embodiment and the first connection points of D1 and D4 of the first hybrid ring resonate with Fo in which the capacitance Cs and the inductance Ls are connected in series. It is coupled by a resonant circuit, and the second terminal P2 and the second connection point between D1 and D2 of the first hybrid ring are coupled by a second series resonant circuit that resonates with Fo in which the capacitance Cs and the inductance Ls are connected in series. There is. Further, a third series in which the third terminal P3 of the hybrid ring circuit 1 of the first embodiment and the seventh connection point of D6 and D7 of the second hybrid ring resonate with Fo in which the capacitance Cs and the inductance Ls are connected in series. It is coupled by a resonant circuit, and the fourth terminal P4 and the eighth connection point between D7 and D8 of the second hybrid ring are coupled by a fourth series resonant circuit that resonates with Fo in which the capacitance Cs and the inductance Ls are connected in series. There is. Furthermore, the third connection point between D2 and D3 of the first hybrid ring of the hybrid ring circuit 1 of the first embodiment and the sixth connection point between D6 and D5 of the second hybrid ring have a capacitance Co and an inductance Lo. It is coupled by a fifth series resonant circuit that resonates with Fo connected in series, and the fourth connection point between D3 and D4 of the first hybrid ring and the fifth connection point between D5 and D8 of the second hybrid ring have a capacitance Co. And the inductance Lo are coupled by a sixth series resonant circuit that resonates with Fo connected in series.

In the hybrid ring circuit 1 of the first embodiment in which two hybrid rings are connected as described above, one end of the first series resonant circuit in which the other end is connected to the first connection point between D1 and D4 of the first hybrid ring. Is the first terminal P1, one end of the second series resonant circuit to which the other end is connected to the second connection point between D1 and D2 is the second terminal P2, and the second hybrid ring D6 and D7. One end of the third series resonant circuit with the other end connected to the 7 connection point is the third terminal P3, and one end of the fourth series resonant circuit with the other end connected to the eighth connection point between D7 and D8 is the first. It is a 4-terminal P4. The opposite side of the first terminal P1 is the fourth terminal P4, and the diagonal direction of the first terminal P1 is the third terminal P3.
In the hybrid ring circuit 1 of the first embodiment, the phase between the terminals in Fo when the first terminal P1 is used as a reference is −180 ° with respect to the fourth terminal P4 on the opposite side corresponding to the passing terminal, and is coupled. It is -270 ° with respect to the third terminal P3 in the diagonal direction corresponding to the terminal. Further, no electric power appears at the second terminal P2 and it becomes an isolation terminal. Even in the phase when the reference terminal is other than the first terminal P1, it is -180 ° for the terminal on the opposite side of the reference input terminal and -270 ° for the diagonal terminal, and the remaining terminals are. It becomes an isolation terminal.

In the hybrid ring circuit 1 of the first embodiment, the impedance connected with the first terminal P1 and the second terminal P2 as input terminals, that is, the input impedance is set to Zoo, and the third terminal P3 and the fourth terminal P4 are connected as output terminals. Impedance, that is, output impedance is also Zo. Then, when the second terminal P2 is terminated by Zo and the power "1" is applied from the first terminal P1, the power ratio that appears in the fourth terminal P4 facing the first terminal P1 is N, and the diagonal of the first terminal P1. If the power ratio appearing at the third terminal P3 of the above is defined as (1-N) and N as the distribution ratio is 0.5, the hybrid ring circuit 1 is evenly distributed. In this case, by setting the distribution ratio of the first hybrid ring and the second hybrid ring to a predetermined distribution ratio N, the hybrid ring circuit 1 of the first embodiment can be set to even distribution. The predetermined distribution ratio N of the first hybrid ring and the second hybrid ring is obtained in (5) above as described with reference to FIG. 29. When formula (5) is reprinted,
N = (2 + √2) / 4 (5)
Will be. The impedance at the third connection point between D2 and D3 of the distributed constant line and the fourth connection point between D3 and D4 of the distributed constant line in the first hybrid ring having the distribution ratio N represented by the equation (5) is shown in FIG. 29. At the sixth connection point between D5 and D6 of the distributed constant line and the fifth connection point between D5 and D8 of the distributed constant line in the second hybrid ring having the impedance Zk described and the distribution ratio N shown in equation (5). The impedance is also Zk, and Zk is obtained in (6) above. When formula (6) is reprinted,
Zk = Zoo / {1 + √0.5} (6)
Will be. Assuming that Zk is obtained by the above equation (6), the hybrid ring circuit 1 of the first embodiment can have the widest bandwidth.

Further, the characteristic impedances of D1 of the distributed constant line in the first hybrid ring and D7 in the second hybrid ring are equal to Z1, and Z1 is obtained by the above equation (7). When formula (7) is reprinted,
Z1 = (1 + √2) Zo (7)
Will be. Further, the characteristic impedances of D3 of the distributed constant line in the first hybrid ring and D5 in the second hybrid ring become equal to Z3, and Z3 is obtained by the above equation (8). When formula (8) is reprinted,
Z3 = (1 + √2) Zk = Zo√2 (8)
Furthermore, the characteristic impedances of the distributed constant lines D2 and D4 in the first hybrid ring and the distributed constant lines D6 and D8 in the second hybrid ring are equal to Z2, and Z2 is obtained by the above equation (9). When formula (9) is reprinted,
Z2 = Zoo / √2 (9)
Will be.

When Zo = 50Ω, Zk is obtained from the above equation (6) to be about 29.289322Ω, and the characteristic impedances Z1, Z2, Z3 are obtained from the above (7) (8) (9).
Z1 ≒ 120.710678Ω
Z2 ≒ 35.355331Ω
Z3 ≒ 70.7106781Ω
Is required.

Here, between the first terminal P1, the second terminal P2, and the first hybrid ring, between the first hybrid ring and the second hybrid ring, the second hybrid ring, the third terminal P3, and the fourth terminal P4. The reason for coupling with the first series resonance circuit or the sixth series resonance circuit that resonates with Fo will be described.
In the conventional wideband hybrid ring circuit 110 shown in FIG. 25, the deviation of the distribution deviation between terminals and the deviation of the amplitude deviation in the maximum band of the coupling loss occurs in the low frequency range where the impedance characteristic seen from the first terminal P111 is Fo. From to Fo, it is inductive, but it was found that the cause is that the capacitance fluctuates from Fo to the high frequency range of Fo. On the other hand, the first series resonance circuit or the sixth series resonance circuit that resonates with Fo in which the capacitance Cs (Co) and the inductance Ls (Lo) are connected in series show capacitance from the low frequency range of Fo to Fo. However, it fluctuates in the reverse direction in an inductive manner from Fo to the high frequency range of Fo. Therefore, between the first terminal P1 and the second terminal P2 and the first hybrid ring, between the first hybrid ring and the second hybrid ring, and between the second hybrid ring and the third terminal P3 and the fourth terminal P4. By coupling between them with a first series resonant circuit or a sixth series resonant circuit that resonates with Fo, the impedance characteristics of the first hybrid ring and the second hybrid ring can be changed to the impedance of the first series resonant circuit or the sixth series resonant circuit. It will be compensated by the characteristics. As a result, it is possible to prevent the deviation of the distribution deviation between terminals and the deviation of the maximum in-band amplitude deviation of the coupling loss from occurring as much as possible.

In addition to the condition of resonating with Fo, as a condition for obtaining the values of the capacitance Cs and the inductance Ls in the first series resonance circuit or the fourth series resonance circuit and the capacitance Co and the inductance Lo in the fifth series resonance circuit and the sixth series resonance circuit. Let Ls, Lo, Cs, and Co in the frequency FL when the low frequency band expansion of Fo is maximized. Since the first hybrid ring and the second hybrid ring are unequally distributed and have different input / output impedances, they are used in the series resonant circuit on the input side of the first hybrid ring and the output side of the second hybrid ring. Capacitance Cs and inductance Ls and the optimum constants of capacitance Co and inductance Lo values in the series resonant circuit on the output side of the first hybrid ring and the input side of the second hybrid ring are difficult to obtain algebraically due to the large number of parameters. It becomes. Therefore, paying attention to the isolation characteristic which is interlocked with the impedance characteristic, the capacitance Cs and the inductance Ls, and the capacitance Co and the inductance Lo are separately obtained.
FIG. 8 shows a circuit diagram showing the configuration of a hybrid ring circuit for obtaining the values of the capacitance Co and the inductance Lo, and the circuit diagram showing the configuration of the hybrid ring circuit for obtaining the values of the capacitance Cs and the inductance Ls is shown in FIG. Shown in 11.

In the hybrid ring circuit 11 shown in FIG. 8, when the wavelength of the center frequency Fo used is λo, four distributed constant lines D1, D2, D3, and D4 having an electric length of λo / 4, respectively, are connected in a ring shape. It is composed of a hybrid ring having an electric length of λo around the circumference. The first terminal P21 of the hybrid ring circuit 11 is connected to the first connection point between D1 and D4 of the hybrid ring, and the second terminal P22 is connected to the second connection point between D1 and D2 of the hybrid ring. The terminal P23 and the third connection point between D2 and D3 of the hybrid ring are coupled by an eleventh series resonant circuit that resonates with Fo in which the capacitance C2 and the inductance L2 are connected in series, and the fourth terminal P24 and the hybrid ring D3 are coupled. The fourth connection point with D4 is coupled by a twelfth series resonant circuit in which the capacitance C2 and the inductance L2 resonate at Fo connected in series.

In the hybrid ring circuit 11, the impedance connected with the first terminal P21 and the second terminal P22 as input terminals, that is, the input impedance is Zo, and the impedance connected with the third terminal P23 and the fourth terminal P24 as output terminals, that is, the output impedance. Let be Zk. Then, when the third terminal P23 and the fourth terminal P24 are terminated by Zk and the power "1" is applied from the first terminal P21, the power ratio appearing at the fourth terminal P24 facing the first terminal P21 is N, the first. The power ratio appearing at the third terminal P23 diagonally of the terminal P21 is defined as (1-N), and N as the distribution ratio is defined as the distribution ratio shown in (5) above. That is, in the hybrid ring circuit 11, the insertion loss between the P21 and P24 terminals is about 0.68763081 dB, and the coupling loss between the P21 and P23 terminals is about 8.343206788 dB. In the hybrid ring circuit 11, the values of the capacitance C2 and the inductance L2 of the 11th series resonance circuit and the 12th series resonance circuit on the output side for which the isolation between the P21 and P22 terminals are optimized are set to the resonance frequency of Fo = 150 MHz. Select on the condition of. Further, although the series resonance circuit is not connected to the input side of the hybrid ring circuit 11, the mismatch loss due to the omission of the series resonance circuit is small with respect to the isolation value, so the constants of the capacitance C2 and the inductance L2. It has little effect on the decision.

The value of the inductance L at which the series resonance frequency becomes 150 MHz when the capacitance C is changed from 30.0 pF to 90.0 pF, and the frequency FL on the lower frequency side than Fo where the isolation of the hybrid ring circuit 11 becomes 20 dB at that time. And the frequency FH on the higher frequency side than Fo are simulated, and the results are shown in the chart of FIG. With reference to the chart shown in FIG. 9, the frequency at which the FL is the lowest and the frequency band is most extended to the low frequency side is 110.930 MHz, and the capacitance C at this time is 59.8 pF and the inductance L is about 18.826 nH. Will be. Further, the frequency at which the FH is the highest and the frequency band is most extended to the high frequency side is 189.054 MHz, and the capacitance C2 at this time is 45.0 pF and the inductance L2 is about 25.018 nH.
By the way, in a resonant circuit having a centralized constant such as the eleventh series resonant circuit, the impedance change from the resonant frequency to the DC is rapid on the low frequency side, while it is gentle in a wide band from the resonant frequency to the infinite frequency on the high frequency side. The impedance changes. Therefore, when a lumped constant circuit is added to a distributed constant line whose impedance change is symmetric with respect to frequency to compensate for impedance characteristics, it is better to prioritize band expansion on the low frequency side for the entire hybrid ring. The symmetry of the frequency band of is improved.

Therefore, when the optimum conditions are FL for the low frequency with isolation of 20 dB and FH for the high frequency, the values of the capacitance C2 and the inductance L2 when the FL is expanded to the lowest frequency are defined as the capacitance C2. Is selected as 59.8 pF and the inductance L2 is selected as 18.826 nH. The frequency characteristics of the isolation between the P21 to P22 terminals of the hybrid ring circuit 11 at this value are shown by a solid line in FIG. 10, and the isolation between the P21 to P22 terminals before connecting the capacitance C2 and the inductance L2 is shown. The frequency characteristics are shown by broken lines in FIG. 10, and the frequency range is 100 to 200 MHz. in this case,
R = Zk ≒ 29.289322 Ω
C2 = 59.8pF
L2 ≒ 18.826nH
With reference to the frequency characteristics of the isolation shown by the solid line in FIG.
FL ≒ 110.943 MHz
FH≈187.619MHz
BW = 76.676MHz
Can be read. BW is a bandwidth calculated by (FH-FL).
Further, referring to the frequency characteristics of the isolation shown by the broken line in FIG. 10,
FL ≒ 129.5 MHz
FH≈170.84MHz
BW = 41.34MHz
Can be read.
Comparing the frequency characteristics of the isolation shown by the solid line in FIG. 10 with the frequency characteristics of the isolation shown by the broken line in FIG. 10, the bandwidth of the hybrid ring circuit 11 having the capacitance C2 and the inductance L2 connected in series is about the same. It can be seen that the magnification is 1.85 times.
From the above, when the values of the capacitance Co and the inductance Lo are obtained, the 11th series resonant circuit and the 12th series resonant circuit in the hybrid ring circuit 11 are connected in series in two stages, that is, the hybrid ring circuit of the first embodiment. Since the fifth series resonant circuit and the sixth series resonant circuit in No. 1, the capacitance Co is 1/2 times the capacitance C2, and the inductance Lo is twice the inductance L2. That is,
Co = C2 / 2 = 29.9pF
Lo = 2L2 ≒ 37.65nH
Is required.

Next, in the hybrid ring circuit 12 shown in FIG. 11, when the wavelength of the center frequency Fo used is λo, the four distributed constant lines D1, D2, D3, and D4 having the electric lengths of λo / 4, respectively, are ring-shaped. The circumference is composed of a hybrid ring having an electric length of λo. In this hybrid ring circuit 12, the first terminal P31 and the first connection point between D1 and D4 of the hybrid ring are coupled by a 21st series resonant circuit that resonates with Fo in which the capacitance C1 and the inductance L1 are connected in series. The second terminal P32 and the second connection point between D1 and D2 of the hybrid ring are connected by a 22nd series resonant circuit that resonates with Fo in which the capacitance C1 and the inductance L1 are connected in series, and the third terminal P33 is D2 of the hybrid ring. And D3 are connected to the third connection point, and the fourth terminal P34 is connected to the second connection point between D3 and D4 of the hybrid ring.

In the hybrid ring circuit 12, the impedance connected with the first terminal P31 and the second terminal P32 as the output terminal, that is, the output impedance is set to Zoo, and the impedance connected with the third terminal P33 and the fourth terminal P34 as the input terminal, that is, the input impedance. Let be Zk. Then, when the first terminal P31 and the second terminal P32 are terminated by Zo and the power "1" is applied from the fourth terminal P34, the power ratio appearing at the first terminal P31 facing the fourth terminal P34 is N, the fourth. The power ratio appearing at the second terminal P32 on the diagonal of the terminal P34 is defined as (1-N), and N as the distribution ratio is defined as the distribution ratio shown in (5) above. That is, in the hybrid ring circuit 12, the insertion loss between the P34-P31 terminals is about 0.68763081 dB, and the coupling loss between the P34-P32 terminals is about 8.343206788 dB. In the hybrid ring circuit 12, the values of the capacitance C1 and the inductance L1 of the 21st series resonance circuit and the 22nd series resonance circuit on the output side for which the isolation between the P34 and P32 terminals are optimized are set to the resonance frequency of Fo = 150 MHz. Select on the condition of. Further, although the series resonance circuit is not connected to the input side of the hybrid ring circuit 12, the mismatch loss due to the omission of the series resonance circuit is small with respect to the isolation value, so the constants of the capacitance C1 and the inductance L1. It has little effect on the decision.

Although not shown in the chart, the value of the inductance L at which the series resonance frequency when the capacitance C is changed is 150 MHz, and the frequencies FL and Fo on the lower frequency side than Fo where the isolation of the hybrid ring circuit 12 is 20 dB at that time. The frequency FH on the higher frequency side is simulated and the result is obtained. Although the chart of the result of this simulation is not shown, the frequency at which FL is the lowest and the frequency band is most extended to the low frequency side is 122.248 MHz, and the capacitance C at this time is 22.1 pF and the inductance L is. It becomes about 50.941 nH. In this case, the optimum conditions are the same as above, and when the low frequency with isolation of 20 dB is FL and the high frequency is FH, the capacitance C1 and the inductance L1 when FL is expanded to the lowest frequency. It is defined as the value of. Then, the capacitance C1 is selected to be 22.1 pF and the inductance L1 is selected to be about 50.941 nH. The frequency characteristics of the isolation between the P33 and P34 terminals of the hybrid ring circuit 12 at this value are shown by the solid line in FIG. 12, and the isolation between the P33 and P34 terminals before connecting the capacitance C1 and the inductance L1 is shown. The frequency characteristics are shown by broken lines in FIG. 12, and the frequency range is 100 to 200 MHz. in this case,
R = Zoo = 50 Ω
C1 = 22.1pF
L1 ≒ 50.941nH
With reference to the frequency characteristics of the isolation shown by the solid line in FIG.
FL ≒ 122.2483MHz
FH≈177.072MHz
BW = 54.824MHz
Can be read.
Further, referring to the frequency characteristics of the isolation shown by the broken line in FIG. 12,
FL ≒ 136.07MHz
FH≈163.99MHz
BW = 27.92MHz
Can be read.
Comparing the frequency characteristics of the isolation shown by the solid line in FIG. 12 with the frequency characteristics of the isolation shown by the broken line in FIG. 12, the bandwidth of the hybrid ring circuit 12 having the capacitance C1 and the inductance L1 connected in series is about the same. It can be seen that the magnification is 1.96 times.

From the above, when the values of the capacitance Cs and the inductance Ls are obtained, the 21st series resonant circuit and the 22nd series resonant circuit in the hybrid ring circuit 12 are the same as the 5th series resonant circuit in the hybrid ring circuit 1 of the first embodiment. Since it is the sixth series resonant circuit, the capacitance Cs is the capacitance C1 and the inductance Ls is the inductance L21. That is,
Cs = C1 = 22.1pF
Ls = L1 ≈ 50.941nH
Is required.

The values of the constants of the first series resonance circuit to the sixth series resonance circuit in the hybrid ring circuit 1 of the first embodiment are summarized as follows. However, it is a real constant when Fo = 150 MHz and Zo = 50 Ω.
Cs = 22.1pF
Ls≈50.941nH
Co = 29.9pF
Lo ≒ 37.65nH
Further, if the above values are normalized by Fo [Hz] and Zo [Ω] to form a general formula, the following is obtained.
Cs [F] ≒ 0.16575 / (Fo ・ Zo)
Ls [H] ≒ (0.15282 ・ Zo) / Fo
Co [F] ≒ 0.22425 / (Fo ・ Zoo)
Lo [H] ≒ (0.11296 ・ Zo) / Fo
The hybrid ring circuit 1 of the first embodiment corresponds to a hybrid ring circuit in which the hybrid ring circuit 11 shown in FIG. 8 and the hybrid ring circuit 12 shown in FIG. 11 are connected, and the characteristic impedances of the distributed constant lines D1 to D7 are as follows. It will be as it is.
Z1 ≒ 120.710678Ω
Z2 ≒ 35.355331Ω
Z3 ≒ 70.7106781Ω
It should be noted that the arrangement of the capacitance and the inductance in the first series resonance circuit or the sixth series resonance circuit is electrically equivalent even if the arrangement is the reverse of the arrangement shown in FIG. It is preferable to determine the sequence for convenience and the like.

In the hybrid ring circuit 1 of the first embodiment, where Fo = 150 MHz and Zo = 50 Ω, the constant values of the first series resonant circuit to the sixth series resonant circuit and the characteristic impedance values of the distributed constant lines D1 to D7 are set as described above. The electrical characteristics when used as values are shown in FIGS. 2 to 7. FIG. 2 is a diagram showing the insertion loss characteristic and the coupling loss characteristic between the P1-P4 terminals, FIG. 3 is a diagram showing the return loss characteristic of the first terminal P1, and FIG. 4 is a diagram showing the isolation between the P1-P2 terminals. 5 is a diagram showing the characteristics, FIG. 5 is a diagram showing the phase characteristics between the P1-P4 terminals, FIG. 6 is a diagram showing the phase characteristics between the P1-P3 terminals, and FIG. 7 is a diagram showing the relative phase deviation characteristics. It is a figure.
In FIG. 2, the solid line shows the frequency characteristic of the insertion loss between the P1-P4 terminals, and the broken line shows the frequency characteristic of the coupling loss between the P1-P3 terminals, and the frequency range is 100 MHz to 200 MHz. .. With reference to FIG. 2, it can be seen that the insertion loss and the coupling loss are evenly distributed at about 3 dB in Fo, and the insertion loss and the coupling loss are also approximately 3 dB in a wide band of about 126 MHz to 176 MHz. Further, referring to the frequency characteristic of the return loss of the first terminal P1 whose frequency range is 100 MHz to 200 MHz shown in FIG. 3, it can be seen that the return loss is 25 dB or more in a wide band of about 126 MHz to 176 MHz.

Further, referring to the frequency characteristics of the isolation between the P1-P2 terminals having the frequency range of 100 MHz to 200 MHz shown in FIG. 4, the isolation between the P1-P2 terminals is the maximum value in Fo, and the isolation. It can be seen that the frequency range in which 25 dB is obtained is a wide band of about 126 to 176 MHz. Further, referring to the frequency characteristic of the phase between the P1-P4 terminals having the frequency range of 100 MHz to 200 MHz shown in FIG. 5, the phase is −180 ° in Fo. Furthermore, referring to the frequency characteristics of the phase between the P1-P3 terminals whose frequency range shown in FIG. 6 is 100 MHz to 200 MHz, the phase is -270 ° in Fo. Furthermore, the relative phase deviation characteristic shown in FIG. 7 shows the frequency characteristic of the relative phase deviation obtained by subtracting the phase between the P1-P4 terminals shown in FIG. 5 from the phase between the P1-P3 terminals shown in FIG. , The frequency range is 100 to 200 MHz. With reference to FIG. 7, it can be seen that a phase of approximately −90 ° is obtained in the wide band frequency range of about 126 to 176 MHz.

Comparing the electrical characteristics of the hybrid ring circuit 1 of the first embodiment shown in FIGS. 2 to 7 with the electrical characteristics of the conventional widebanded hybrid ring circuit 110, the return loss characteristics, the isolation characteristics, and the relatives are compared. All of the phase deviation characteristics have been improved, and in particular, the inter-terminal and in-band amplitude deviations in the insertion loss and coupling loss characteristics have been significantly improved. Comparing the insertion loss characteristics and the coupling loss characteristics shown in FIGS. 2 and 26, when the bandwidth of 126 MHz to 176 MHz of 50 MHz, which has an isolation and return loss of about 25 dB or more, is used as the frequency band, the insertion loss and the coupling loss are used. In the conventional hybrid ring circuit 110, the deviation is about 1.3 dB as shown in FIG. 26, but in the hybrid ring circuit 1 of the first embodiment, the deviation between the insertion loss and the coupling loss is as shown in FIG. It can be seen that the improvement is made to 0.1 dB or less.

By the way, in the above description, the frequency FL on the lower frequency side than Fo where the isolation is 20 dB is calculated, but it is not necessary to limit the isolation set when calculating the FL to 20 dB. Therefore, when the isolation set when calculating FL is set to 15 dB and 30 dB, the constant of the series resonant circuit obtained by the same procedure as the above procedure is obtained, as shown below. Become. It should be noted that Fo = 150 MHz and Zo = 50 Ω.
If the isolation is set to 15 dB,
Cs = 29.1pF
Ls≈38.690nH
Co = 44.3pF
Lo ≒ 25.413nH
If the above value is normalized by Fo [Hz] and Zo [Ω] to make a general formula,
Cs [F] ≒ 0.21825 / (Fo ・ Zo)
Ls [H] ≒ (0.11606 ・ Zo) / Fo
Co [F] ≒ 0.33225 / (Fo ・ Zoo)
Lo [H] ≒ (0.076239 ・ Zo) / Fo
Will be.

If the isolation is set to 30 dB,
Cs = 17.1pF
Ls≈65.836nH
Co = 22.1pF
Lo ≒ 50.941nH
If the above value is normalized by Fo [Hz] and Zo [Ω] to make a general formula,
Cs [F] ≒ 0.12825 / (Fo ・ Zo)
Ls [H] ≒ (0.19751 ・ Zo) / Fo
Co [F] ≒ 0.16575 / (Fo ・ Zo)
Lo [H] ≒ (0.15282 ・ Zo) / Fo
Will be.
Although not shown, the series resonant circuit in the hybrid ring circuit 1 of the first embodiment is obtained based on the FL calculated in the case where the isolation is set to 15 dB and the case where the isolation is set to 30 dB. The electrical characteristics when the constant is set to 20 dB are not significantly different from those when the isolation is set to 20 dB, but when the isolation is set to 15 dB, the wide band is generally widened, but the deviation between the insertion loss and the coupling loss increases. On the other hand, when it is set to 30 dB, the band is generally narrow, but the ideal transmission characteristic is that there is almost no deviation between the insertion loss and the coupling loss. From this, it is preferable to select the isolation to be set according to the desired frequency characteristics.

<Second Example>
FIG. 14 shows a circuit diagram showing the configuration of the hybrid ring circuit according to the second embodiment of the present invention.
The hybrid ring circuit 2 of the second embodiment shown in FIG. 14 is a hybrid ring circuit in which the distributed constant line in the hybrid ring circuit 1 of the first embodiment is made into a lumped constant. By making the distributed constant line a lumped constant, it is possible to reduce the size and easily realize a hybrid ring circuit. That is, in the hybrid ring circuit 1 of the first embodiment, the total number of distributed constant lines constituting the first hybrid ring and the second hybrid ring is as large as eight, and each has a line length of 1/4 wavelength. Therefore, it may become large depending on the frequency used. Further, since the characteristic impedance of the distributed constant lines D1 and D7 is a high impedance exceeding 100Ω, it may be difficult to create the distributed constant line because the line width becomes very narrow when the distributed constant line is formed by a microstrip line. However, these problems do not occur in the hybrid ring circuit 2 of the second embodiment.

In explaining the hybrid ring circuit 2 of the second embodiment, it will be described that the distributed constant line is made into a lumped constant. The 1/4 wavelength distributed constant line is electrically considered to be a 90 ° phase circuit, and FIG. 13 shows an example of a circuit diagram of a 90 ° phase circuit PH which is a lumped constant circuit. The 90 ° phase circuit PH shown in FIG. 13 is configured by connecting a π-type connection circuit to which an LPF circuit is applied in two stages. In the first stage π-type connection circuit, two capacitances Cd101 and Cd102 are shunt-connected to the ground, and one inductance Ld101 is connected in series between the capacitances Cd101 and Cd102 to form a 45 ° phase. The second-stage π-type connection circuit consists of three elements in which two capacitances Cd102 and Cd103 are shunt-connected to the ground and one inductance Ld102 is connected in series between the capacitances Cd102 and Cd103. It is a 45 ° phase circuit. As a result, the overall phase of the phase circuit PH becomes 90 °. In the π-type connection circuit of the LPF circuit configuration, if the capacitance is C, the inductance is L, the center frequency used is Fo, the characteristic impedance of the entire circuit is Zt, and the desired phase amount is θo, the capacitance C and inductance of the π-type connection circuit. The constant of L can be obtained by the following equations (11) and (12).
C = (1-cosθo) / (2πFo ・ Zt ・ sinθo) (11)
L = (Zt · sinθo) / (2πFo) (12)

Returning to FIG. 14, the hybrid ring circuit 2 of the second embodiment is shown in FIG. 13 in which the distributed constant lines D1 to D7 of the hybrid ring circuit 1 of the first embodiment are connected in two stages with a π-type connection circuit having an LPF circuit configuration. It is composed of a 90 ° phase circuit. That is, in the hybrid ring circuit 2 of the second embodiment, the three capacitances Cd1 and Cd2 and the three capacitances Cd1 in which the distributed constant line D1 of the first hybrid ring of the hybrid ring circuit 1 is shunt-connected to the ground. , A 90 ° phase circuit consisting of two inductances Ld1 connected in series between Cd2, and three capacitances Cd2, Cd3, Cd4 in which the distributed constant line D2 of the first hybrid ring is shunted to the ground. And a 90 ° phase circuit consisting of two inductances Ld2 connected in series between the three capacitances Cd2, Cd3 and Cd4, and the distributed constant line D3 of the first hybrid ring was shunted to the ground. It is composed of a 90 ° phase circuit consisting of three capacitances Cd4 and Cd5 and two inductances Ld3 connected in series between the three capacitances Cd4 and Cd5, and the distributed constant line D4 of the first hybrid ring is between the ground and the ground. It is composed of a 90 ° phase circuit consisting of three capacitances Cd2, Cd3 and Cd4 shunt-connected and two inductance Ld2 connected in series between the three capacitances Cd2, Cd3 and Cd4. As a result, the first hybrid ring has an electric length of λo around it.

Further, in the hybrid ring circuit 2 of the second embodiment, the three capacitances Cd4 and Cd5 and the three capacitances Cd4 in which the distributed constant line D5 of the second hybrid ring of the hybrid ring circuit 1 is shunt-connected to the ground. , A 90 ° phase circuit consisting of two inductances Ld3 connected in series between Cd5, and three capacitances Cd2, Cd3, Cd4 in which the distributed constant line D6 of the second hybrid ring is shunted to the ground. And a 90 ° phase circuit consisting of two inductances Ld2 connected in series between the three capacitances Cd2, Cd3 and Cd4, and the distributed constant line D7 of the second hybrid ring was shunted to the ground. It is composed of a 90 ° phase circuit consisting of three capacitances Cd1 and Cd2 and two inductances Ld1 connected in series between the three capacitances Cd1 and Cd2, and the distributed constant line D8 of the second hybrid ring is between the ground and the ground. It is composed of a 90 ° phase circuit consisting of three capacitances Cd2, Cd3 and Cd4 shunt-connected and two inductance Ld2 connected in series between the three capacitances Cd2, Cd3 and Cd4. As a result, the second hybrid ring has an electric length of λo around it.

Further, the first terminal P41 of the hybrid ring circuit 2 of the second embodiment and the first connection point A of the first hybrid ring are coupled by a first series resonant circuit that resonates with Fo in which the capacitance Cs and the inductance Ls are connected in series. The second terminal P42 and the second connection point B of the first hybrid ring are coupled by a second series resonant circuit that resonates with Fo in which the capacitance Cs and the inductance Ls are connected in series. Further, the third terminal P43 of the hybrid ring circuit 2 of the second embodiment and the seventh connection point G of the second hybrid ring are coupled by a third series resonant circuit that resonates with Fo in which the capacitance Cs and the inductance Ls are connected in series. The fourth terminal P44 and the eighth connection point H of the second hybrid ring are coupled by a fourth series resonant circuit that resonates with Fo in which the capacitance Cs and the inductance Ls are connected in series. Furthermore, the third connection point C of the first hybrid ring of the hybrid ring circuit 2 of the second embodiment and the sixth connection point F of the second hybrid ring resonate at Fo in which the capacitance Co and the inductance Lo are connected in series. A sixth series resonance in which the fourth connection point D of the first hybrid ring and the fifth connection point E of the second hybrid ring resonate at Fo in which the capacitance Co and the inductance Lo are connected in series by being coupled by the fifth series resonance circuit. It is connected by a circuit.

In the hybrid ring circuit 2 of the second embodiment in which the first hybrid ring and the second hybrid ring are two connected as described above, the first series in which the other end is connected to the first connection point A of the first hybrid ring. One end of the resonant circuit is the first terminal P41, the other end of the second series resonant circuit connected to the second junction B is the second terminal P42, and the seventh junction G of the second hybrid ring. One end of the third series resonant circuit to which the other end is connected is the third terminal P43, and one end of the fourth series resonant circuit to which the other end is connected to the eighth connection point H is the fourth terminal P44. The opposite side of the first terminal P41 is the fourth terminal P44, and the diagonal direction of the first terminal P41 is the third terminal P43.
In the hybrid ring circuit 2 of the second embodiment, the phase between the terminals in Fo when the first terminal P41 is used as a reference is −180 ° with respect to the fourth terminal P44 on the opposite side corresponding to the passing terminal, and is coupled. It is -270 ° with respect to the third terminal P43 in the diagonal direction corresponding to the terminal. Further, no electric power appears at the second terminal P42 and it becomes an isolation terminal. Even in the phase when the reference terminal is other than the first terminal P41, it is -180 ° for the terminal on the opposite side of the reference input terminal and -270 ° for the diagonal terminal, and the remaining terminals are. It becomes an isolation terminal.

In the hybrid ring circuit 2 of the second embodiment, the impedance connected with the first terminal P41 and the second terminal P42 as input terminals, that is, the input impedance is set to Zoo, and the third terminal P43 and the fourth terminal P44 are connected as output terminals. Impedance, that is, output impedance is also Zo. Then, when the second terminal P42 is terminated by Zo and the power "1" is applied from the first terminal P41, the power ratio that appears in the fourth terminal P44 facing the first terminal P41 is N, and the diagonal of the first terminal P41. If the power ratio appearing at the third terminal P43 of the above is defined as (1-N) and N as the distribution ratio is 0.5, the hybrid ring circuit 2 is evenly distributed. In this case, by setting the distribution ratio of the first hybrid ring and the second hybrid ring to a predetermined distribution ratio N, the hybrid ring circuit 2 of the second embodiment can be set to even distribution. The predetermined distribution ratio N of the first hybrid ring and the second hybrid ring is the distribution ratio of the unequal distribution obtained by the above equation (5). The impedance at the third connection point C and the fourth connection point D in the first hybrid ring having the distribution ratio N represented by the above equation (5) is the impedance Zk, and the sixth connection point F and the fifth connection point in the second hybrid ring. The impedance in E is also Zk, and Zk is obtained by the above equation (6).

The capacitances Cd1 to Cd5 and the inductances Ld1 to Ld3 in the hybrid ring circuit 2 of the second embodiment are obtained from the above equations (11) and (12) with Fo = 150 MHz and Zo = 50 Ω.
Cd1 ≈ 7.2818pF
Cd2 ≈ 16.072pF
Cd3 ≒ 24.862pF
Cd4 ≒ 18.646pF
Cd5 ≈ 12.431pF
Ld1 ≒ 90.565nH
Ld2 ≒ 26.526nH
Ld3 ≒ 53.052nH
Is required. Further, the values of the capacitance Cs and the inductance Ls of the first series resonance circuit or the fourth series resonance circuit and the capacitance Co and the inductance Lo of the fifth series resonance circuit and the sixth series resonance circuit are the values of the hybrid ring circuit of the first embodiment. It can be obtained by the same procedure as in 1, and is obtained as follows.
Cs = 20.9pF
Ls≈53.866nH
Co = 27.6pF
Lo ≒ 40.790nH

When the above obtained value is normalized by Fo [Hz] and Zo [Ω] to make a general formula, it becomes as follows.
Cd1 [F] ≒ 0.054613 / (Fo · Zo)
Cd2 [F] ≒ 0.12054 / (Fo · Zoo)
Cd3 [F] ≒ 0.18646 / (Fo ・ Zoo)
Cd4 [F] ≒ 0.13985 / (Fo ・ Zoo)
Cd5 [F] ≒ 0.10073 / (Fo ・ Zoo)
Ld1 [H] ≒ (0.27169 ・ Zo) / Fo
Ld2 [H] ≒ (0.079577 ・ Zoo) / Fo
Ld3 [H] ≒ (0.15915 ・ Zo) / Fo
Cs [F] ≒ 0.15675 / (Fo ・ Zo)
Ls [H] ≒ (0.16160 ・ Zo) / Fo
Co [F] ≒ 0.20700 / (Fo ・ Zoo)
Lo [H] ≒ (0.12237 ・ Zo) / Fo

In the hybrid ring circuit 2 of the second embodiment, where Fo = 150 MHz and Zo = 50 Ω, the values of the capacitances Cd1 to Cd5 and the inductances Ld1 to Ld3 and the constant values of the first series resonance circuit to the sixth series resonance circuit are set as described above. The electrical characteristics when used as values are shown in FIGS. 15 to 20. FIG. 15 is a diagram showing the insertion loss characteristic and the coupling loss characteristic between the P41 and P44 terminals, FIG. 16 is a diagram showing the return loss characteristic of the first terminal P41, and FIG. 17 is a diagram showing the isolation between the P41 and P42 terminals. It is a figure which shows the characteristic, FIG. 18 is a figure which shows the phase characteristic between P41-P44 terminal, FIG. 19 is a figure which shows the phase characteristic between P41-P43 terminal, and FIG. 20 is a figure which shows the relative phase deviation characteristic. It is a figure.
In FIG. 15, the frequency characteristic of the insertion loss between the P41 and P44 terminals is shown by the solid line, and the frequency characteristic of the coupling loss between the P41 and P43 terminals is shown by the broken line, and the frequency range is 100 MHz to 200 MHz. .. With reference to FIG. 15, it can be seen that the insertion loss and the coupling loss are evenly distributed at about 3 dB in Fo, and the insertion loss and the coupling loss are approximately 3 dB in a wide band of about 130 MHz to 175 MHz. Further, referring to the frequency characteristic of the return loss of the first terminal P41 whose frequency range is 100 MHz to 200 MHz shown in FIG. 16, it can be seen that the return loss is 25 dB or more in a wide band of about 130 MHz to 175 MHz.

Further, referring to the frequency characteristics of the isolation between the P41 and P42 terminals whose frequency range is 100 MHz to 200 MHz shown in FIG. 17, the isolation between the P41 and P42 terminals is the maximum value in Fo, and the isolation. It can be seen that the frequency range in which 25 dB is obtained is a wide band of about 130 to 175 MHz. Further, referring to the frequency characteristic of the phase between the P41-P44 terminals whose frequency range is 100 MHz to 200 MHz shown in FIG. 18, the phase is −180 ° in Fo. Furthermore, referring to the frequency characteristics of the phase between the P41 and P43 terminals whose frequency range is 100 MHz to 200 MHz shown in FIG. 19, the phase is -270 ° in Fo. Furthermore, the relative phase deviation characteristic shown in FIG. 20 shows the frequency characteristic of the relative phase deviation obtained by subtracting the phase between the P41 and P44 terminals shown in FIG. 18 from the phase between the P41 and P43 terminals shown in FIG. , The frequency range is 100 to 200 MHz. With reference to FIG. 20, it can be seen that a phase of approximately −90 ° is obtained in the wide band frequency range of about 130 to 175 MHz.

With reference to the electrical characteristics shown in FIGS. 15 to 20, it can be seen that the hybrid ring circuit 2 of the second embodiment has almost the same electrical characteristics of the hybrid ring circuit 1 of the first embodiment. Further, when the input terminal is P41, it is -180 ° with respect to the P44 terminal on the opposite side and -270 ° with respect to the diagonal P43 terminal, so that it is diagonal to the input terminal. It can be seen that the output terminal functions as a "90 ° hybrid circuit" whose phase is delayed by 90 ° with respect to the terminal on the opposite side.
In the hybrid ring circuit 2 of the second embodiment, when n is an integer of 2 or more, a unit phase circuit having a phase of 90 ° / n may be connected in n stages to form a 90 ° phase circuit. For example, if a 90 ° phase circuit is formed by connecting a unit phase circuit of 30 ° in three stages, the characteristics of the hybrid ring circuit 1 of the first embodiment can be further approached. In this way, by increasing the number of lumped constant elements in the 90 ° phase circuit, the characteristics of the 90 ° phase circuit can be asymptote to the characteristics of the distributed constant line. Further, the 90 ° phase circuit may be configured by using a T-type connection circuit having an LPF circuit configuration instead of the π-type connection circuit.

In the hybrid ring circuit of the embodiment according to the present invention described above, the parameter value as an electric constant is not limited to the parameter value described above, and is equivalent to the function and operation described above in each hybrid ring circuit. As long as it is a parameter value capable of exerting the function and action of, the present invention is not limited to the parameter value described above. That is, this parameter value has a permissible range above and below the parameter value described above, and this permissible range is set to be a range in which the functions and actions equivalent to the functions and actions described above are exhibited in each hybrid ring circuit.
In the hybrid ring circuit of the embodiment according to the present invention described above, the first hybrid ring and the second hybrid ring are connected to each other, and between the first terminal and the second terminal and the first hybrid ring, the third terminal and the third hybrid ring. The fourth terminal and the second hybrid ring, and the first hybrid ring and the second hybrid ring are coupled by a series resonance circuit that resonates at the center frequency Fo used. By coupling with a series resonant circuit, the impedance characteristics of the first hybrid ring and the second hybrid ring are compensated, and the electrical characteristics in the passing frequency band with Fo as the center frequency are improved. In this case, the frequency of the entire hybrid ring is set by setting the value of the inductance and the capacitance constituting the series resonant circuit to a value at which a predetermined isolation can be obtained at a frequency lower than Fo and at the lowest frequency. Band symmetry can be improved as much as possible to make the band wider. Alternatively, the frequency can be set to a value higher than Fo and a predetermined isolation can be obtained at the highest frequency, and even in this case, the symmetry of the frequency band of the entire hybrid ring should be improved. Can be done.

In the hybrid ring circuit of the embodiment according to the present invention described above, the circuit constant of the series resonant circuit can be normalized by Fo and the impedance Zo of the first terminal to the fourth terminal and expressed by a general formula. Further, the distributed constant line having the electric length of λo / 4 constituting the first hybrid ring and the second hybrid ring is composed of a low-pass type 90 ° phase circuit composed of a lumped constant inductance and a capacitance. can do. In this case, when n is an integer of 2 or more, a 90 ° / n phase unit phase circuit can be connected in n stages to form a 90 ° phase circuit.

1 hybrid ring circuit, 2 hybrid ring circuit, 11 hybrid ring circuit, 12 hybrid ring circuit, 100 hybrid ring circuit, 110 hybrid ring circuit, 120 hybrid ring circuit, D1, D2, D3, D4 distributed constant line, D5, D6, D7, D8 distributed constant line, P1, P21, P31, P41 1st terminal, P2, P22, P32, P42 2nd terminal, P3, P23, P33, P43 3rd terminal, P4, P24, P34, P44 4th terminal , D101, D102, D103, D104 distributed constant line, D111, D112, D113, D114, D115, D116, D117 distributed constant line, P101, P111 1st terminal, P102, P112 2nd terminal, P103, P113 3rd terminal, P104, P114 4th terminal, PH phase circuit

Claims (5)

When the center frequency used was Fo and the wavelength of Fo was λo, four distributed constant lines having an electric length of λo / 4 were connected at the first connection point to the fourth connection point to form a ring shape. With the first hybrid ring
Four distributed constant lines having an electric length of λo / 4 are connected at the fifth connection point to the eighth connection point to form a ring, and the second hybrid ring connected to the first hybrid ring and the second hybrid ring.
A first series resonant circuit that resonates with Fo that connects the first terminal and the first connection point of the first hybrid ring,
A second series resonant circuit that resonates with Fo that connects the second terminal and the second connection point of the first hybrid ring,
A third series resonant circuit that resonates with Fo that couples the third connection point of the first hybrid ring and the sixth connection point of the second hybrid ring.
A fourth series resonant circuit that resonates with Fo that couples the fourth connection point of the first hybrid ring and the fifth connection point of the second hybrid ring.
A fifth series resonant circuit that resonates with Fo that connects the seventh connection point of the second hybrid ring and the third terminal, and the fifth series resonant circuit.
A sixth series resonant circuit that resonates with Fo that connects the eighth connection point of the second hybrid ring and the fourth terminal is provided.
The impedance characteristics of the first hybrid ring and the second hybrid ring are compensated by the first series resonant circuit or the sixth series resonant circuit configured by connecting the inductance and the capacitance in series, centering on Fo. A hybrid ring circuit characterized in that the electrical characteristics in the passing frequency band as a frequency are improved. The values of the inductance and the capacitance constituting the first series resonant circuit or the sixth series resonant circuit are set to values at which a predetermined isolation can be obtained at a frequency lower than Fo and at the lowest frequency. The hybrid ring circuit according to claim 1, wherein the hybrid ring circuit is characterized in that. When the impedance of the first terminal to the fourth terminal is Zo, the value of the capacitance in the first series resonance circuit, the second series resonance circuit, the fifth series resonance circuit, and the sixth series resonance circuit is A / (Fo · Zo), the capacitance value in the third series resonant circuit and the fourth series resonant circuit is B (Fo · Zo), the first serial resonant circuit and the second series resonant circuit. The value of the inductance in the fifth series resonant circuit and the sixth series resonant circuit is (C.Zo) / Fo, and the value of the inductance in the third series resonant circuit and the fourth series resonant circuit is (D. The hybrid ring circuit according to claim 1, wherein the constant A to the constant D is normalized as Zo) / Fo and becomes a value corresponding to a predetermined isolation value to be obtained. The distributed constant line having the electric length of λo / 4 constituting the first hybrid ring and the second hybrid ring is a low-pass type 90 ° phase circuit composed of an inductance and a capacitance of a lumped constant. The hybrid ring circuit according to claim 1, wherein the hybrid ring circuit is configured. The hybrid ring circuit according to claim 4, wherein when n is an integer of 2 or more, a unit phase circuit having a phase of 90 ° / n is connected in n stages to form the 90 ° phase circuit.

Images