JPH0211170B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electromagnetic delay line formed by combining an inductance element and a capacitor in a ladder shape.
This invention relates to improvements in electromagnetic delay lines that can obtain a wide range of rise characteristics up to relatively high speeds, and can be used in digital and analog circuits.

[Prior art and its problems]

Such an electromagnetic delay line with a relatively fast rise time is formed by connecting multiple inductances in series to form an inductance element, and by connecting a capacitor between each adjacent inductance and the ground to form a ladder shape. In particular, in order to reduce the size of the inductance, there is a structure in which these inductances are coaxially wound at predetermined intervals on a rod-shaped bobbin.

In such an electromagnetic delay line, the engagement coefficient formed between adjacent inductances is a ₁ , the coupling coefficient formed between two adjacent inductances is a ₂ , and the coupling formed between two adjacent inductances is coefficient
a ₃ , the coupling coefficient formed between (n-1) inductances is _ao , especially the coupling coefficient a ₁ ,
It is known that a ₂ greatly affects the delay characteristics of electromagnetic delay lines.

Conventionally, the value of the coupling coefficient a ₁ is set to a ₁ = 0.1 ~
It is said that good delay characteristics can be obtained by selecting the value of the coupling coefficient a ₂ to be _{approximately 0.2, the value of the coupling coefficient a 2 to be approximately −0.015 to −0.03, and the value of the coupling coefficient a 3 to be} approximately 0.01 to 0.02. ing.

In order to obtain such good delay characteristics, conventionally, the direction of coupling of each inductance making up the electromagnetic delay line has been devised to obtain a positive coupling coefficient a ₁ and a negative coupling coefficient a ₂ .

However, when constructing an electromagnetic delay line, it is actually difficult to obtain the above-mentioned theoretical optimum value or a value close to this as the value of the coupling coefficients a ₁ and a ₂ between the inductances in the inductance element. In particular, when a plurality of inductances are coaxially wound on a rod-shaped bobbin and connected in series, the values of the coupling coefficients a ₁ and a ₂ tend to become large.

Moreover, if the direction of coupling is changed, such as by changing the winding direction of the inductance, in order to obtain the optimum values of the coupling coefficients a ₁ and a ₂ , the structure of the inductance tends to become complicated and manufacturing becomes troublesome.

[Purpose of the invention]

The present invention has been made under these circumstances, and aims to provide an electromagnetic delay line that is easy to obtain the optimum value of the coupling coefficient, provides good delay characteristics, and has a simple structure.

[Structure and effects of the invention]

That is, the present invention provides an electromagnetic delay line comprising an inductance element wound with a conductor and a capacitor connected between the conductor and the ground, and having a plurality of sections, in which the inductance element winds the conductor an integer number of turns. the first interval and this first interval
Second sections different by 0.5 turns from the sections are arranged alternately, and the numbers of positive mutual induction and negative mutual induction are made different between the conductors of the first and second sections.

According to the configuration of the present invention, it is easy to obtain an optimal coupling coefficient between the inductances forming the inductance element, and good delay characteristics such as a fast rise time can be obtained. It has the advantage of being simple.

[Embodiments of the invention]

The details of the present invention will be explained below.

1 and 2 are a schematic front view and a schematic side view showing an embodiment of the electromagnetic delay line of the present invention, and FIG. 3 is an equivalent circuit diagram thereof.

1 and 2, a flat bobbin 1 having a rectangular cross section is wound with a conductor 2 space-wound in the form of a single-layer solenoid with a pitch P to form an inductance element 3. Note that the symbol W in the figure is the distance between the conductors 2 in the long side direction of the bobbin 1,
The symbol T is the distance between the conductors 2 in the short side direction of the bobbin 1.

In the inductance element 3, for example, the first
Based on the conductor 2 ( ₁ point A) on the bottom left side of the bobbin 1 in the figure, the 1.5th turn, 1st turn, ... conductor 2 ( ₂ points A, ₃ points A, respectively) - the following 1.5 turns and 1st turn A capacitor C is connected in a ladder-like manner between - and ground to form an electromagnetic delay line 4.

The electromagnetic delay line 4 configured in this manner has 1.5 turns of winding as the second section of inductance L, and 1 turn of winding as the first section of inductance L'.
These sections are alternately arranged as shown in FIG. 3.

In the second section of the inductance L and the other first and second sections, the coupling coefficients are determined in order from the adjacent sections.
a ₁ , a ₂ , a ₃ , ..., and between the first section of the inductance L' and the other first and second sections, the coupling coefficients a ₁ , a ₂ ' are applied in order from the adjacent sections. , a ₃ ,
It is connected by... That is, for even-numbered connections, the first and second sections have different values.

In addition, in FIG. 3, attention is paid to the section on the left side of the figure, and the connections on the right side are shown, but in reality, there are also connections on the left side, making it symmetrical.

Next, the electromagnetic delay line configured in this way will be considered in detail.

Figure 4 shows only the conductor ² in the cross section taken along line X-X' _in Figure 1. This figure shows the mutual induction relationship between the conductors on the lower surface of the upper surface on the W side located on the right side of the upper surface.

In the same figure, since the direction of current is the same in the same column, they form a positive connection and are sequentially M ₀₁ , M ₀₂ , M ₀₃ ,
..., and since the direction of the current is opposite to that of the other columns, it becomes a negative coupling and has M ₁₁ , M ₁₂ , M ₁₃ , ...
In addition, there is a symmetrical same bond on the left side of the figure,
All conductors other than those shown with diagonal lines have similar connections.

For ease of explanation, a case will be considered in which T is smaller than W and the T side can be omitted.The portion surrounded by the broken line in FIG. 4 is a group of conductors constituting one section.

The conductor group on the left constitutes an inductance L consisting of three conductors, the next conductor group consists of two conductors and constitutes an inductance L', and thereafter the three conductor groups and the two conductor groups are repeated in order. Here, in every other three conductor groups, 0.5 turn portions are arranged vertically alternately.

In this case, the relationship between the inductances L, L' and the coupling coefficients a ₁ , a ₂ , a ₂ ', and a ₃ in Figure 3 can be expressed by the following formula, assuming that the inductance of one conductor is Ls. .

L=3・Ls+2・M ₀₁ −4・M ₁₁ ………(1) L′=2・Ls−2・M ₁₁ ………(2) a ₂ =2・M ₀₂ +2・M ₀₃ −M ₁₂ −3・M ₁₃ −M ₁₄
/L……(4) a ₂ ′=M ₀₂ +M ₀₃ −2・M ₁₃ /L′……(5) Paying attention to the number of positive and negative mutual inductions in each of the above-mentioned equations (3) to (6), it can be seen that there are three positive and negative mutual inductions for the odd-numbered coupling coefficients _a1 and _a3 . On the other hand, in the even-numbered coupling coefficient a ₂ , there are four positive and five negative coupling coefficients, and there are two each of the positive and negative coupling coefficients a ₂ ′. That is, the number of mutual inductions in which only the coupling coefficient a ₂ is negative is one more. The value of mutual induction increases as the distance between the conductors 2 becomes smaller, but since each mutual induction value in the same formula belongs to the same conductor group, the values do not differ greatly,
It is composed of multiple mutual inductions that differ slightly from each other.

Therefore, in the conventional electromagnetic delay line, L = L' and a ₂ =
a ₂ ′, but in the configuration of the present invention described above, generally
a ₁ > a ₂ ′ > a ₃ > 0 and a ₂ < 0. Therefore, |a ₂ |
> a ₂ ′, the positive value of a ₂ ′ is compensated for by the negative value of a ₂ , and overall the combination of a ₂ and a ₂ ′ has the ideal characteristic of a negative value. You can do it like this.

As described above, the present invention is characterized in that negative coupling is easily realized by increasing the number of negative mutual inductions between the conductors 2 in each section than the number of positive mutual inductions, and the inductance The structure of element 3 becomes very simple.

In addition, in the above-mentioned configuration, the second section where the conductor 2 is wound for 1.5 turns and the first section where the conductor 2 is wound for 1 turn are arranged alternately, that is, the first section is arranged alternately.
An example is shown in which the section is an integer number of turns, and the second section is 0.5 turns more. However, in the present invention, it is also possible to implement a combination of a first section having an integer number of turns of 2 or more and a second section having an integer number of turns of 0.5 turns or more.

The inventor of the present invention uses a bare conductor wire with a wire diameter of 0.1 mm, W=6 mm,
T = 0.4 mm, P = 3.1 mm, wound in a single layer solenoid shape with 45 turns spaced, inductance L' with 2 integer turns, and 2.5 with 0.5 turns added to it.
A capacitor C with a capacitance value of 2.3 pF is connected so that the inductance L of the turn is arranged alternately, and the sections of inductance L and L' are arranged alternately, 10 sections each for a total of 20
An electromagnetic delay line arranged in sections was constructed.

In this case, the theoretical values of the bond line a ₁ = 0.114, a ₂ = -
0.047, a ₂ ′ = 0.031, a ₃ = 0.019, characteristic impedance is 100Ω, delay time is inductance L
section is 250 ps per section, inductance
High speed performance was achieved with a delay time of 200 ps per section of L', a total delay time of 4.5 ns for 20 sections, and a rise time of 400 ps. FIG. 5 shows another embodiment of the electromagnetic delay line of the present invention.

The structure of an inductance element 3 in which a conducting wire 2 is wound around a bobbin 1 is the same as that shown in FIG. The same is true for one turn between the _two integer turns and the _three points A, except that the turn between the _one point A and the _two points A consists of 0.5 turns, which is 0.5 turns less than the integer turns.

An electromagnetic delay line with such a configuration is also represented by the same equivalent circuit as in Fig. 3, and if Fig. 3 is expressed by the same mutual induction between conductors as in Fig. 4, L = Ls ...... (7) L' = 2・Ls−2・M ₁₁ ………(8) a ₂ = −M ₁₂ /L ………(10) a ₂ ′=M ₀₁ +M ₀₂ −2・M ₁₂ /L′ ………(11) Therefore, only equation (10) for a ₂ has no positive mutual induction and only one negative mutual induction, so the number of negative mutual inductions is greater than the number of positive mutual inductions,
Otherwise, the number of positive and negative mutual inductions will be equal.

Therefore, only the coupling coefficient a ₂ is negative, and the other coupling coefficients a ₁ , a ₂ ′, and a ₃ are positive. In this case also |a ₂ |>
By setting a ₂ ′, a good coupling coefficient can be easily obtained.

By the way, in the present invention, the integer turns are 2.
Even if the number of turns is more than 0.5 turns, various combinations can be created by alternately combining the number of turns with 0.5 turns less than the number of turns. In short, the object of the present invention can be achieved by alternately arranging a first section in which the conductor is wound with an integral number of turns and a second section which is different from the first section by 0.5 turns.

In order to simplify the explanation, the above embodiments have been explained using the case where W≫T so that the T side of the inductance element 3 can be ignored. However, even if the ratio of W and T is arbitrarily determined, Good delay characteristics can be achieved by appropriately selecting the wire diameter, etc.

Further, the bobbin 1 may have any shape other than a square, such as a circle or an ellipse, and the conductor 2 may also be formed into a conductor strip or other shape by etching, in addition to having a circular cross section.

As explained above, the electromagnetic delay line of the present invention includes a first section in which a conductor is wound in an integral number of turns, and a first section in which a conductor is wound in integral turns.
The second sections are alternately arranged different from the sections by 0.5 turn, and the inductance elements have different numbers of positive and negative mutual inductions between the conductors of the first and second sections, so that the inductance element It becomes easy to obtain the optimum coupling coefficient for each section, good delay characteristics are obtained, and the configuration of the inductance element is simplified.

[Brief explanation of drawings]

1 and 2 are a schematic front view and a schematic side view showing one embodiment of the electromagnetic delay line of the present invention, and FIG.
The figure shows the equivalent circuit diagram of the electromagnetic delay line shown in Figure 1, and the equivalent circuit diagram of the electromagnetic delay line shown in Figure 4.
This figure is a diagram for explaining the connection between the sections of the electromagnetic delay line shown in FIG. 1, and FIG. 5 is a schematic cross-sectional view showing another embodiment of the electromagnetic delay line of the present invention. 1...Bobbin, 2...Conductor, 3...Inductance element, _a1 , _a2 , _a2 ', _a3 ...Coupling coefficient, C...
...Capacitor, L, L'...Inductance.

Claims (1)

[Scope of Claims] 1. An electromagnetic delay line comprising an inductance element wound with a conductor and a capacitor connected between the conductor and ground, and having a plurality of sections, wherein the inductance element winds the conductor with an integral number of turns. A first section with a difference of 0.5 turns from the first section and a second section different from the first section by 0.5 turns are arranged alternately, and positive mutual induction and negative mutual induction are formed between the conductors of the first and second sections. An electromagnetic delay line characterized by having different numbers. 2. The electromagnetic delay line according to claim 1, wherein the second section is wound 0.5 turns more than the first section. 3. The electromagnetic delay line according to claim 1, wherein the second section is wound 0.5 turns less than the first section.