JPH0810810B2 - Hybrid circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hybrid circuit that divides an input signal into two output signals so that the output signals have a predetermined phase difference.

[Prior Art] FIG. 6 is a circuit diagram of a conventional 90-degree hybrid circuit (Hideho Yamamura, "Encyclopedia of Toroidal Core Utilization," 1983 1
Mon, CQ Publishing, pp366, see Figures 6-39).

In this conventional 90-degree hybrid circuit, for example, a bifilar winding that forms two inductors L1 and L2 is wound around a toroidal core, and a capacitor C1 is connected between each end of the inductors L1 and L2. A capacitor C2 is connected between the other ends of L2. here,
Both ends of inductor L1 are ports P1 and P2, and both ends of inductor L2 are ports P3 and P4.
Is grounded through a terminating resistor R _L equal to the characteristic impedance Z ₀ .

In the conventional 90-degree hybrid circuit configured as described above, when a high-frequency signal having a reference phase of 0 degrees is input to the port P1 from the high-frequency signal oscillator 30 having an output resistance Rs equal to the characteristic impedance Z ₀ , the high-frequency signal becomes 2 A signal having a phase of −45 degrees and a signal having a phase of +45 degrees are output to the ports P2 and P3, respectively, while no signal is output to the port P4. That is, the phase difference between the signals output to the ports P2 and P3 is 90 degrees and the amplitude levels of the signals are the same.

[Problems to be Solved by the Invention] In the conventional 90-degree hybrid circuit described above, the degree of coupling between the inductors L1 and L2 is proportional to the length of the winding, but in general, the length of the winding wound around the toroidal core. Since the inductors L1 and L2 cannot be coupled to a higher degree, the phase difference between the signals output to ports P2 and P3 can be adjusted to 90 degrees in a wide frequency band. There was a problem that it was difficult.

The object of the present invention is to solve the above problems, and it is possible to adjust the phase difference between the signals output to the ports P2 and P3 to a predetermined phase difference in a wide frequency band, and to operate in a wider frequency band than in the past. It is to provide a possible hybrid circuit.

[Means for Solving the Problems] In the hybrid circuit according to the present invention, the first, second, and third solid wires forming a set close to each other are wound around a magnetic core, and the second and third solid wires are Connected in parallel, one end of the first single wire is an input end, the other end of the first single wire is a first output end, and one end of the second and third single wires on the input end side is a first end. It is characterized in that the output end is 2.

Also, in the hybrid circuit, the first, second and third single wires are preferably trifilar windings.

Further, in the hybrid circuit, the magnetic core is preferably a toroidal core or an eyeglass type core.

[Operation] In the hybrid circuit configured as described above,
When a high frequency signal is input to the input terminal which is one end of the first single wire, the input high frequency signal is divided into two, and each of the two is divided into two.
The distributed signal is output to the first output end which is the other end of the first single wire and the second output end which is one end on the input end side of the second and third single wires. The phase difference of
It is possible to output so as to have a predetermined phase difference of 90 degrees.

Here, the second and third single wires are connected in parallel and the first
Since it is wound around the magnetic core close to the single wire, the degree of coupling between the inductor formed by the first single wire and the inductor formed by the second and third single wires is larger than that of the conventional one. can do. Therefore, it becomes easier to adjust the phase difference between the signals output to the first and second output terminals to a predetermined phase difference of 90 degrees, for example, over a wider frequency band than in the conventional case. It is possible to realize a hybrid circuit that can operate in a wide band.

Embodiments Embodiments according to the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a 90-degree hybrid circuit which is an embodiment of the present invention, and FIG. 2 is an equivalent circuit of the 90-degree hybrid circuit.

In FIG. 1, a toroidal core 10 is provided with a set of trifilar windings 1 consisting of three single wires 1, 2, and 3 which are close to each other.
00 penetrates the hole 11 of the toroidal core 10 and is closely attached to the surface of the toroidal core 10 and is wound for a plurality of turns.
Here, one end of the single wire 1 is electrically connected to the port P1,
The other end of the single wire 1 is electrically connected to the port P2, and the single wires 2, 3
Each of the one ends on the port 1 side is electrically connected to the port P3, and the other ends of the single wires 2 and 3 are electrically connected to the port P4.

As shown in FIG. 2, among the three single wires 1, 2, and 3 of the trifilar winding 100, the single wire 1 constitutes the inductor L11, the single wire 2 constitutes the inductor L12, and the single wire 3 constitutes the inductor L13.
Is composed. Therefore, the inductors L12, L13 are connected in parallel, and the inductors L11, L12, L13 are coupled to each other via the toroidal core 10 by inductive coupling. Also,
Both ends of the inductor L11 are connected to the ports P1 and P2, respectively, and both ends of the inductors L12 and L13 that are connected together are connected to the ports P3 and P4, respectively.

Each single wire 1, 2, 3 of the trifilar winding 100 is formed by covering the copper core wire 4 with a polyurethane jacket 5 as shown in FIG. 4 (A).
The cross sections of the single wires 1, 2, and 3 are juxtaposed on a straight line so that the single wire 1 is located between the single wires 2 and 3, and the copper core wires 4 are parallel and the outer jackets 5 are close to each other in close contact with each other. It is arranged and configured.

In the 90-degree hybrid circuit configured as above, the output resistance equal to the characteristic impedance Z ₀ is applied to port P1.
When a high frequency signal is input from the high frequency signal oscillator 30 having Rs, the high frequency signal is divided into two, and output signals having a phase difference of 90 degrees are output to the ports P2 and P3.

The present inventor wound a toroidal core 10 made of carbonyl iron having an outer diameter of 10 mm, an inner diameter of 9 mm and a thickness of 5 mm, and winding a trifilar winding 100 having a core wire diameter of 0.3 mm for 3 turns, and illustrated in FIG. Create a 90 degree hybrid circuit of this embodiment,
Further, a bifilar winding having a core diameter of 0.3 mm was wound around the same toroidal core 10 as the toroidal core 10 for 5 turns to prepare a hybrid circuit of a comparative example shown in FIG.
For each hybrid circuit, the forward transfer coefficient S ₂₁ between the port P1 and the port P2 and the forward transfer coefficient S ₃₁ between the port P1 and the port P3 were measured.

FIG. 7 is a graph showing the frequency characteristics of the forward transfer coefficients S ₂₁ and S ₃₁ of the 90-degree hybrid circuit of the embodiment shown in FIGS. 1 and 2, and FIG. 8 is shown in FIG. 7 is a graph showing frequency characteristics of forward transfer coefficients S ₂₁ and S ₃₁ of the hybrid circuit thus prepared.

In the comparative example, as is clear from FIG. 8, ports P2 and P
The amplitude of each signal output to 3 is the same when the signal frequency is about 150 MHz.
The signals attenuated by 4.5 dB are output to ports P2 and P3. At this time, the phase difference Δθ between the signals output to ports P2 and P3
Is about 78 degrees. Further, it can be seen that this phase difference Δθ changes depending on the frequency.

On the other hand, in this embodiment, as is apparent from FIG. 7, the amplitudes of the signals output to the ports P2 and P3 are the same when the signal frequency is about 150 MHz. The signals attenuated by about 3.5 dB are output to the ports P2 and P3, and the phase difference Δθ between the signals output to the ports P2 and P3 is about 90 degrees. The phase difference Δθ is about 10
It can be seen that it is almost constant over a wide frequency band from 0 MHz to about 350 MHz. Therefore, the degree of coupling between the inductor L11 and the inductors L12 and L13 can be increased as compared to the comparative example, which allows the 90-degree hybrid circuit to operate over a wider frequency band than the comparative example. .

As described above, the toroidal core 10 is wound with the trifilar winding 100, and two of the trifilar windings 100 are wound.
Since the single wires 2 and 3 are connected in parallel to form a 90-degree hybrid circuit, the degree of coupling between the single wire 1 forming the inductor L11 and the single wires 2 and 3 forming the inductors L12 and L13 is determined by the bifilar winding. It can be made larger than that of the comparative example configured by using the line, which makes it easy to set the phase difference between the two output signals to 90 degrees over a wide frequency band. Therefore, a 90-degree hybrid circuit that can be used in a wide band can be constructed.

In the above embodiment, the trifilar winding 100 is wound around the toroidal core 10 to form a 90-degree hybrid circuit, but the present invention is not limited to this, and as shown in FIG. A 90-degree hybrid circuit may be formed by winding the trifilar winding 100 in a portion that connects the two holes 21 and 22 and penetrates the holes 21 and 22 and is in close contact with the surface of the core 20.

In the above embodiment, the trifilar winding 100 is the fourth
Although it is configured as shown in FIG. 4A, the present invention is not limited to this and may be configured so that the intervals between the copper core wires 4 are equal as shown in FIG. 4B.

Although the 90-degree hybrid circuit has been described in the above embodiments, the present invention is not limited to this, and the input signal is adjusted so that the phase difference between the output signals becomes a predetermined phase difference.
It can be applied to a distributing hybrid circuit.

[Effect of the Invention] As described in detail above, according to the present invention, the first, second, and third single wires that are close to each other and form a set are wound around the magnetic core,
Since the second and third single wires are connected in parallel, the degree of coupling between the inductor formed by the first single wire and the inductor formed by the second and third single wires is larger than that of the conventional one. can do. Therefore, it becomes easier to adjust the phase difference between the signals output to the two output terminals to a predetermined phase difference, for example, 90 degrees, over a wider frequency band than in the conventional case, and thus it is possible to operate in a wide band. There is an advantage that a hybrid circuit can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view of a 90-degree hybrid circuit according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing an equivalent circuit of the 90-degree hybrid circuit shown in FIG. 1, and FIG. FIG. 4 is a perspective view showing a modified example of the 90-degree hybrid circuit according to FIG. 4, FIGS. 4A and 4B are cross-sectional views of the trifilar winding used in the 90-degree hybrid circuit of FIG. 1, and FIG. 5 is a toroidal core. FIG. 6 is a circuit diagram showing an equivalent circuit of a hybrid circuit of a comparative example which is constructed by winding a bifilar winding on a wire, FIG. 6 is a perspective view of a conventional 90-degree hybrid circuit, and FIG. 7 is shown in FIGS. FIG. 8 is a graph showing the frequency characteristic of the forward transfer coefficient of the 90-degree hybrid circuit of the illustrated embodiment, and FIG. 8 is a graph showing the frequency characteristic of the forward transfer coefficient of the hybrid circuit of the comparative example shown in FIG. is there. 1,2,3 …… Single wire, 10 …… Toroidal core, 20 …… Glasses core, 100 …… Trifiler winding, P1, P2, P3, P4 …… Port.

Claims (3)

[Claims] 1. A first core wire, a second core wire, and a third core wire, which are close to each other and form a pair, are wound around a magnetic core, and the second core wire and the third core wire are connected in parallel, and one end of the first core wire is connected. As the input end, the other end of the first single wire as the first output end, and the one end on the input end side of the second and third single wires as the second output end. circuit. 2. The hybrid circuit according to claim 1, wherein the first, second and third single wires are trifilar windings. 3. The hybrid circuit according to claim 1, wherein the magnetic core is a toroidal core or an eyeglass type core.