JPH0451082B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a lumped constant electromagnetic delay line that combines an inductance element and a capacitor, and more particularly to an electromagnetic delay line that has an ultra-fast rise time and little output waveform distortion.

[Prior art and its problems]

Conventionally, lumped constant electromagnetic delay lines have been created by winding a conductor around a bobbin to form an inductance element.
It is known that a capacitor is connected between the conducting wire and the ground at each predetermined turn of the inductance element, and the inductance element has a configuration consisting of a plurality of sections.

However, in the electromagnetic delay line configured in this manner, it is difficult to select the optimum polarity and value of the coupling coefficient between sections in the inductance element in a high frequency band. In particular, it is difficult to select optimal values for the coupling coefficients between adjacent sections and the coupling coefficients between adjacent sections.

As a result, the rise time is fast, about 1 ns,
Moreover, it was difficult to obtain an electromagnetic delay line with good output waveform distortion.

[Purpose of the invention]

The present invention has been made to solve these conventional drawbacks, and its object is to provide an electromagnetic delay line with an extremely fast rise time, little output waveform distortion, and good delay characteristics.

[Structure and effects of the invention]

In order to achieve this object, the present invention provides a folded conductor line in which conductors intersecting a virtual axis and conductors parallel to the virtual axis are alternately formed, between the center part of the conductor intersecting the virtual axis and the ground. An electromagnetic delay line consisting of a plurality of sections is configured by connecting capacitors, the length of the conducting wire parallel to the virtual axis is made larger than the interval between the adjacent center portions, and the center of the conducting wire that intersects the virtual axis Both sides of the part are deformed in opposite directions so that the conductive wires parallel to the virtual axis approach each other.

According to the configuration of the present invention, it becomes possible to easily select and adjust the optimum coupling state in the inductance element in a high frequency band, thereby achieving ultra-high speed rise time and distortion of the output waveform. It is possible to improve the delay characteristics.

[Embodiments of the invention]

The details of the present invention will be explained below.

1 and 2 are a developed view and a perspective view showing an embodiment of the electromagnetic delay line of the present invention.

In the figure, a folded conductive line 1 having a rectangular folded shape and constituting an inductance element has a folded conductor 2 whose center portion is bent orthogonal to a virtual axis (horizontal virtual line in Figure 1, not shown). The conductive wire 2 is slightly parallel to the imaginary axis, and the conductive wire 3 is formed between the ends of the conductive wire 2 parallel to the imaginary axis. A capacitor C is connected between each central portion of the conducting wire 2 and the ground, thereby configuring a lumped constant electromagnetic delay line having a plurality of sections.

The folded conductor path 1 has an effective length between the conductor wires 2 in one section (length between the centers of the conductor wires 2)
is longer, and the effective length G2 between adjacent conducting wires 2 (the length between the centers of adjacent conducting wires 2) in one interval is shorter than the pitch P. And these relationships are shown as follows.

P = (X + G2) / 2 ... (1) The unfolded folded conductor line 1 is an imaginary line drawn parallel to the imaginary axis line in the middle of the conductor 2 in each section so as to sandwich the center of each conductor 2. Q-Q, R-
At R, the conductive wires 2 are each bent at right angles in opposite directions, and the conductive wires 2 in adjacent sections are made to face each other, as shown in FIGS. 2 and 4A. That is, the conductive wires 2 in adjacent sections are configured to overlap and face each other when viewed from the longitudinal cross-sectional direction.

This folded conductor path 1 is
A conductive wire is connected to a capacitor C which has a ground electrode 5 formed on one main surface (lower surface in the figure) of a flat and elongated dielectric plate 4 and a plurality of capacitor electrodes 6 formed at predetermined intervals on the opposite main surface (upper surface in the figure). The center part of 2 is the capacitive electrode 6
It is connected and installed.

FIG. 3 shows an equivalent circuit diagram of the electromagnetic delay line of the present invention, and symbols S0, S1, and S2 in the figure indicate sections on the right side in sequence with respect to the section on the left side in FIG. The symbol a ₁ is the coupling coefficient between the section S0 and the section S1 adjacent to the right side, and the symbol a ₂ is the coupling coefficient between the section S0 and the section S2 that is connected to the right side.

Note that FIG. 4 is a side view of one section of the conductor 2 of the folded conductor path 1 viewed from the side in the cross-sectional direction.

Next, we will discuss the coupling coefficient in the electromagnetic delay line configured in this way.

Generally, when considering the coupling coefficient in the folded conductor line 1, there are coupling coefficients between all the conductors that form the folded conductor line 1 and the angles between the conductors are not right angles, but among them, the one with the largest value will be considered. By doing so, it is possible to know the tendency of the coupling coefficient of the folded conductive line 1.

Therefore, in the electromagnetic delay line of the present invention, the coupling between the opposing conductors 2 and 2 and between the conductors 3 and 3 in the above-mentioned FIG. 2 and FIG. do.

When the current flows in the folded conductor line 1 in the direction of the arrows shown in FIGS. 1 and 2, the sections S0,
Regarding the coupling coefficient a ₁ between S1, A-B and E-F are mainly involved among the conducting wires 3 parallel to the virtual axis. Since the direction of current is the same between AB and EF, positive coupling affects the coupling coefficient _a1 .

Then, the distance G1 between A-B and E-F of the conductor 3
As shown in FIG. 4A, since the conductor 2 is bent at right angles, the imaginary lines Q-Q, R in FIG.
- equal to the spacing Z of R. Therefore, by changing the interval Z, the value of the coupling coefficient _a1 can be varied.

On the other hand, regarding the coupling coefficient a ₂ between the sections S0 and S2, B-D and G-H are mainly involved among the conductors 2 perpendicular to the virtual axis, but between B-D and G-H, the direction of the current is is in the opposite direction, so the coupling coefficient a ₂
is affected by negative coupling.

The distance G2 between the conductive wires 2 shown in FIG.
Since it is possible to arbitrarily determine the above equation (1), the coupling coefficient a ₂ can be varied.

Similarly, for the coupling coefficient an, odd-numbered coupling coefficients are positive for the same reason as above,
Even-numbered coupling coefficients are negative.

When examining the delay characteristics of the electromagnetic delay line of the present invention in detail, it is necessary to calculate the coupling coefficients a ₁ , a ₂ , ... an by considering the coupling of other conductor parts in addition to the coupling described above. However, in the electromagnetic delay line of the present invention, odd-numbered coupling coefficients tend to be positive and even-numbered coupling coefficients tend to be negative, which is a desirable configuration for an electromagnetic delay line.

In general, in the case of an electromagnetic delay line, the coupling coefficients a ₁ and a ₂ have a large influence on the delay characteristics, and according to the present invention, the polarities of the coupling coefficients a ₁ and a ₂ are set to desired polarities, that is, the coupling coefficient It is easy to set a ₁ to be positive and the coupling coefficient a ₂ to be negative, and the pitch P, the effective length X of the conducting wire 3 for one section, and the effective length G2 between the adjacent conducting wires 2 in one section apart. , and the virtual line Q-Q,R
By appropriately selecting the angle of bending at −R, etc., it is easy to bring the value of the coupling coefficient close to the optimum value.

In the present invention, the folded conductive line 1 can be easily formed by photoetching a copper foil or a copper plate, or can be formed by bending a conductive wire having a circular cross section.

In the above embodiment, the folded conductor line 1 has an air-core free-standing structure, but a copper foil with a thin insulating film pasted thereon is formed by photo-etching or the like, and is wound together with the insulating film around a rectangular bobbin or the like. It is also possible.

As a specific example, the present inventor has provided a diameter of 0.2 mm.
Using the conductor, pitch P = 2.05mm, X = 3.7mm,
The experiment was conducted using the following dimensional relationships: Z=G1=0.45mm, G2=0.4mm, and Y=1.5mm.

Then, the coupling coefficient in the inductance element is
a ₁ = 0.161, coupling coefficient a ₂ = -0.0313, coupling coefficient a ₃ =
0.0085, and when combined with a capacitor of 2pF to form a 20-section electromagnetic delay line, the total delay time is
We were able to obtain an ultrahigh-speed electromagnetic delay line with a characteristic impedance of 2ns, a characteristic impedance of 50Ω, and an output pulse rise time of approximately 250ps.

The embodiment of the present invention described above is based on the virtual line Q-
Bending at right angles at Q and R-R, the distance between the conductor wires 3 parallel to the imaginary axis and the conductor 2 that intersects with the imaginary axis
An example is shown in which the intervals between the two are equal. However, in the present invention, the bending angle can also be arbitrarily selected according to the desired characteristics. For example, as shown in Figure 4B, the bending angle is set to 90° or more to deform the cross section into a triangular or circular shape when viewed from the cross-sectional direction, so that the conductors intersect with the imaginary axis rather than the interval between the conductors 3 parallel to the imaginary axis. It is possible to configure the conductor wires 2 by increasing the distance between them.

Rather, in the present invention, as shown in FIGS. 4B and 4C, the spacing G1 between the conducting wires ₃ , which mainly affects the coupling coefficient a ₁ , is made small as in FIG. It is preferable to increase the interval between the conductive wires 2 in adjacent sections in the Y direction (direction perpendicular to the virtual axis) related to .

That is, although the total value of the coupling of the conductive wires 2 in the Y direction related to the coupling coefficient _a1 is not a large value, this becomes a negative coupling, and among the conductive wires 3 in FIGS. 1 and 2, A-B, Since it weakens the positive coupling between E and F, it is desirable to increase the spacing between the conductors 3 in the Y direction to reduce the effect of negative coupling.

In addition, in the present invention, the conducting wire 2 is not limited to the case where it is formed so as to be orthogonal to the virtual axis line, but can also be formed so that it intersects diagonally.

As explained above, in the electromagnetic delay line of the present invention, the length of the conductive wire parallel to the virtual axis is made larger than the interval between adjacent central portions, and both sides of the central portion of the conductive wire that intersects with the virtual axis are Since the conducting wires parallel to the virtual axis are deformed in opposite directions so as to approach each other, it is easy to select the polarity and value of the coupling coefficient in the desired direction.

Therefore, in the ultra-high frequency band, the rise is extremely fast, output waveform distortion can be suppressed to a small level, and delay characteristics are improved.

[Brief explanation of drawings]

Fig. 1 is a developed view showing one embodiment of the electromagnetic delay line of the present invention, Fig. 2 is an assembled perspective view of the electromagnetic delay line shown in Fig. 1, and Fig. 3 is an equivalent of the electromagnetic delay line shown in Fig. 1. The circuit diagram and FIG. 4 are side views of the electromagnetic delay line of the present invention viewed from the cross-sectional direction. 1...Returning conductor line, 2...Conductor line crossing the virtual axis line, 3...Conductor line parallel to the virtual axis line, a ₁ , a ₂ ,
an...Coupling coefficient, C...Capacitor, S0, S
1, S2... section.

Claims (1)

[Scope of Claims] 1. A capacitor is connected between the center part of the conductor that intersects with the imaginary axis and ground in a folded conductor line that is formed alternately of conductors that intersect with the imaginary axis and conductors that are parallel to the imaginary axis. constitute an electromagnetic delay line consisting of a plurality of sections, the length of the conducting wire parallel to the imaginary axis is greater than the interval between the adjacent central portions, and both sides of the central portion of the conducting wire that intersects the imaginary axis are , an electromagnetic delay line characterized in that conductors parallel to the virtual axis are deformed in opposite directions so as to approach each other. 2. The electromagnetic delay line according to claim 1, wherein the distance between the conductive wires parallel to the virtual axis is equal to the distance between the conductive wires crossing the virtual axis. 3. The electromagnetic delay line according to claim 1, wherein the distance between the conducting wires parallel to the virtual axis is narrower than the distance between the conducting wires crossing the virtual axis.