JPS58145209A - Delay line - Google Patents

Abstract

PURPOSE:To speed up the leading time, by specifying the shape of an inductance element, in a lump constant time delay line combining the inductance element and a capacitor. CONSTITUTION:A conductor 2 is wound around a rod shaped bobbin 1 having rectangular shape, T in thickness and W in width, in the lengthwise direction of the bobbin in a pitch P, with space winding of single solenoid, to form the inductance element 3. A capacitor C is connected between the conductor 2 and ground at each turn of the inductance element 3. The pitch P of the inductance element 3 and the winding width T at the shorter side has the relation of 0.2< P/T<1.9. Thus, the leading time is quickened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lumped constant type delay line formed by combining an inductance element and a capacitance, and particularly to a super-high-contact single line that has an extremely fast rise time and is suitable for digital circuits.

Conventionally, delay lines with a fast rise time, for example, a rise time of less than Ins, have been constructed by cutting a coaxial cable to a length that provides the desired delay time, or are considered to be a type of distributed constant circuit such as a meander line. A configuration has been proposed. However, +iIjg has a large shape and terminal processing is troublesome, and the back is large and expensive, and its characteristics are not good, so none of the delay lines have been put into practical use.On the other hand, inductance elements and capacitors There is also a lumped constant delay line that combines However, in a delay line with this configuration, in a high operating frequency band (for example, 1 GHz or higher), the inductance element has a frequency characteristic and the Q of the inductance element also decreases, deteriorating both the delay characteristic and the amplitude characteristic, so the rise time is Ins. It has become difficult to obtain a high-speed delay line with the following characteristics.

The present invention has been made to solve the above-mentioned drawbacks.
The aim is to provide an ultra-small, ultra-high-speed, and inexpensive delay line.

In order to achieve this object, the present invention forms a single-layer solenoid-like inductance element with a pitch P having a space with a conductor, and inserts and connects a capacitor between the conductor and ground for each turn of this inductance element. , the pitch P of the inductance element and the winding diameter T in the minor axis direction are set to have a relationship of 1 0.2 < P/T < 1.9.

The present invention will be explained in detail below.

FIG. 1 is a schematic diagram for explaining the present invention in detail.
FIG. 2 is an equivalent circuit diagram of the delay line shown in FIG. 1. 1st
In the figure, an inductance element 3 is formed by space-wound a conductive wire 2 in a single-layer solenoid shape at a pitch P in the longitudinal direction on a rod-shaped non-magnetic pobbin 1 having a rectangular cross-section and a thickness ■ and a width W. Note that the thickness and width dimensions T and W are, more precisely, the thickness and width of the conductor 2 on the opposite surface in the width direction of the bobbin 1.
The distance between the centers of

One turn of the inductance element 3 is an inductance L, a capacitor C is inserted and connected between the conductor 2 and the ground for each turn, and the inductance L for one turn is one section of the delay line. The inductance L is mutually inductively coupled to another inductance L as shown in FIG. Note that in Fig. 2, only the leftmost inductance is connected to the inductance L on the right side, but naturally there is also an inductance L on the left side, and it is also connected to them in the same way. Other inductance L
are similarly coupled to the left and right inductances L.

Then, each inductance t, a, and II is coupled with a coupling coefficient al, the second inductance is lead, and the nth inductance is coupled with a coupling coefficient a1. ing.

Next, consider the delay line of the present invention. First, the coupling coefficient a1+a
1+..., find ayu.

Using any one conductor having the width W on the top surface of the bobbin 1 in FIG. 1 as a reference, the coupling coefficient between the conductors on the top surface of the bobbin is determined sequentially as shown in FIG. ....

kln' The coupling coefficient between the conducting wires on the lower surface of the bobbin is sequentially set to 1+, 3+"""+ kln-1+ k, and B+1.

Considering the current flowing through the reference conductor, the currents flow in the same direction for the conductor on the -L plane, resulting in positive coupling, and the currents flow in the opposite direction for the conductor on the lower surface, so the coupling becomes negative. The absolute value of the coupling coefficient becomes smaller as the distance between the conducting wires becomes longer.

To simplify the explanation, if the dimensions of width W and thickness T shown in FIG. .

The delay characteristics of the delay line are mainly determined by these coupling coefficients a1. a.

First, let us consider the coupling coefficient a1.

Assuming that the sign of al is positive and there is no value below a, conventional theoretical calculations indicate that a = 0.142 (corresponding to m = 1.34 in the induced m-type) is optimal.

However, in practice, it is necessary to take into account the existence of couplings below a and the influence of stray capacitance, and in the end, studies have been carried out in the range of about a=0.1 to 02.

On the other hand, when the coupling coefficient in Fig. 3 is 1, 3 constitutes
When the conductors of the book are located at equal intervals from each other (at each vertex of a regular triangle), It<1=kt.

Therefore, under these conditions, the above equation (1) becomes
becomes. As is clear from FIG. 3, the relationship Fi1 between the coupling coefficient R and 3 is +>lk and 1, so under this condition, the coupling coefficient alI/ia+>O is always satisfied. In other words, the relationship between the pitch P and the dimension ■ in the thickness direction in the same figure is
T-(1/?J/2) p or P/T=1.15
5, it is easily seen that al>0. When P/T increases beyond this condition, it passes through the point of 81=0 and a I
<O, that is, al becomes negative. On the other hand, P/T is 1.1
When it decreases from 55, 81 increases monotonically. When P/T is changed in this way, 8. increases or decreases.

Next, the coupling coefficient aI will be considered.

Theoretically, the sign of a is negative, and its absolute value is 002 to 0.
It is said that around 03 is good. On the other hand, from the spacing between each conductor in Fig. 3, the coupling coefficient kH+ is 4·k.
It can be seen that the relationship is lkl Dk+>lk+ 1, and these absolute values are quite close. As a result, the value of the numerator of the above equation (2) becomes considerably small, and the coupling coefficient a also becomes very small. Further, when the pitch P shown in the figure decreases, 81 increases positively.

In addition, the coupling coefficient a++..., am is ~ the above (3
) formula and Figure 3, k t n-+ L:=k t n #k r n+
It is considered that i, and the value is almost negligible.

Figure 4 shows the case where W/T is 1.10.100 for al, and the case where W/T is 1 for a and a, using the dimension ratio W/T of width W and thickness T as a parameter. It is a characteristic diagram obtained from a theoretical formula for the relationship with P/T in the case of
Furthermore, the wire diameter of the conductor is d, and Figure 4A shows the case where the relationship between the wire diameter d and the thickness T is d/T=0.02 (a relatively small ratio within a practical range). B is the same < d/T=0.
9 (the ratio that can be maximized within a practical range) is shown.

From the same figure, when W/i is 1, that is, the cross section of bobbin 1 is square, W/T is 100, that is, when bobbin 1 is very thin and plate-shaped, d/T is 002,
In other words, if the wire diameter d of the conducting wire is selected to be relatively small, then d
yT25 export, 9. In other words, in a wide practical range when the wire diameter of the conductor is selected to be very thick, the delay line pitch P
By appropriately selecting the relationship between T and thickness T, the optimum value of the coupling coefficient 81 can be easily determined. In that case, the coupling coefficient a! is suppressed to a small positive value that has almost no effect on the delay characteristics, making it possible to make the coupling coefficient a and below negligible, and only the coupling coefficient a exists.Characteristics that are very close to those of an induced m-type delay line can be obtained.

However, when configuring an actual delay line, the delay characteristics are affected by the distributed capacitance between the inductances, the inductance of the capacitor lead connected to the inductance, etc., so a delay line with even delay characteristics is obtained. In order to achieve this, the coupling coefficient a is selected to be from 0.1 to 02. Furthermore, the delay characteristic of the delay line is not limited to a flat delay characteristic, but may have a sloped delay characteristic for the purpose of phase compensation of the external circuit, so the coupling coefficient a = 0.05 to 0.2
It is practical to select around 5.

As can be seen from FIG. 4, even in a large range of W/T and d/T values, the coupling coefficient 81 can be set at 0.05 to 0.05.
P/T is 0.2 to make it in the range of 25 (Fig. 8A).

By selecting a value in the range from point Q) to 1.9 (points B and R in FIG. 8), an inductance element having a desired coupling coefficient of 81 can be easily constructed.

To summarize these relationships, by selecting the pitch P and thickness direction dimension ■ of the inductance element within the range of the relationship 0.2 (P/T (1,9(5)), various state highways can be used. It was found that a suitable Yunobu wire could be obtained.

Based on the above theoretical study regarding the delay line, specific embodiments of the delay line of the present invention will be shown below.

In FIG. 5, the inductance element 3 is constructed by attaching a silver-plated bare conductive wire 2 to the outer periphery of a rectangular rod-shaped nonmagnetic bobbin 1 whose width is slightly shorter than W and whose thickness is also slightly shorter than T. It is wound in a single layer solenoid shape with pitch P, width W, and thickness T. A capacitive element 7 is inserted and connected between the conducting wire 2 and the ground for each turn of the inductance element 3. This capacitive element 7 includes a dielectric plate 6 extending in the longitudinal direction at the bottom of the bobbin 1, and a dielectric plate 6 extending downwardly from the dielectric plate 5.
A plurality of capacitor electrodes 4 are formed on the upper surface at the same pitch as the pitch P of the inductance element 3. The delay line 8 is constructed by connecting the conductive wire 2 on the lower short side of the inductance element 3 and the capacitor electrode 4 by a solder reflow method or the like.

In the delay line 8 having such a configuration, most of the conducting wire 2 of the inductance element 3 is away from the ground electrode 6, so there is little loss in the inductance element 3 due to overcurrent, and multiple pieces can be easily arranged in parallel, resulting in high performance. Suitable for density mounting.

The inventor proposed that the delay line of the configuration shown in FIG. 5 has a diameter of 0.
An inductance element 3 is formed by winding 40 turns of silver-plated bare copper wire with a pitch P0.411, a thickness TO, 6fiW, and a width W2 to a length of 16mm, and a capacitance 4 of 0.5PF.
When this experiment was carried out using a combination of capacitive elements 7 having 0 elements, the characteristic impedance was 100 Ω, the delay time was 2 ns, the rise time was 150 pS, and the -3 dB passband was 23 GHz. Despite its structure, it is ultra-high speed and has a large delay time to rise time ratio (approximately 13.3), achieving good characteristics that were not possible with conventional lumped delay lines. .

In addition, in the present invention, as shown in FIG. 6, the inductance element 3
Since the solder is fixed for each turn and can stand on its own, if the non-magnetic bobbin 1 is pulled out from the delay line 8 and used in an air-core free-standing structure, the dielectric loss of the bobbin 1 at ultra-high frequencies can be further reduced. can do.

FIG. 6 shows another embodiment of the invention.

This delay line 8 is constructed by forming an inductance element 3 by forming conductor strips 21 at a pitch P on a non-magnetic bobbin 1 having a rectangular cross section.
is also used as a capacitive electrode 4', and is combined with a capacitive element 7 with a dielectric plate 6 sandwiched therebetween and facing the ground electrode 6.

Also in this configuration, the relationship between pitch P and thickness T is 0.
If it is selected within the range of 2<P/T<1.9, good delay characteristics can be obtained and the structure of the capacitive element 7 can be simplified.

Furthermore, the present invention is not limited to the example of using the bobbin 1 with a rectangular cross section, but it is also possible to use a bobbin with a circular or elliptical cross section as shown in FIG. 7, for example. In these bobbins as well, the diameter of the circle and the short axis of the ellipse are T, and the inductance element 3 may be constructed according to the relationship of 0.2 (P/T (1, 9). You can think of it as consisting of

FIG. 8 shows still another embodiment of the present invention. Delay in figure! fM is a non-magnetic bobbin 1' in which a toroidal bobbin (
(indicated by a two-dot chain line in the figure), and is equipped with an inductance element 3 (indicated by three turns in the figure) in which a conducting wire 2 is space-wound in a single-layer solenoid shape around this toroidal non-magnetic bobbin 1'. . This delay line has a different pitch P1 on the inner circumferential side and a pitch P2 on the outer circumferential side of the bobbin 1', and naturally P
+ < p l, but the pitch P in the above equation (5) is one average pinch, that is, P = (PI + P + )/2
The above equation (5) may be applied as follows.

The delay line with such a configuration can be formed into an annular shape such as a frame shape, but especially if a toroidal bobbin is used, it becomes possible to form an arc-shaped fixed contact array, and the bobbin Since the movable contacts can very easily slide on the fixed contact array using the center as a fulcrum, it is possible to realize a variable delay line that is small and easy to operate.

As explained above, the delay line of the present invention has a simple structure, has a large degree of freedom in design such as shape and conductor wire diameter, is ultra-high speed, and can obtain arbitrary delay characteristics. It also has the following major features:

The coupling coefficients that determine the delay characteristics of the delay line are determined not by the absolute values of the dimensions that make up the delay line, but by the ratio of the dimensions, and the relationship between the dimensions that make up one extension line and the characteristics can be clearly obtained. . In other words, if all the dimensions constituting the delay line are reduced in proportion to 1/S (however, the capacitance C is also set to a value of 1/8), the characteristic impedance remains unchanged and the delay time and rise time become 1/S. 5 (-3dE1 passband is 8 times) - The installation area is 1/8" and the volume is 1/8".

This means that by miniaturizing the delay line of the present invention,
This means that it will be possible to dramatically increase speed and density. The inductance element 3 used in the delay line of the present invention has a very simple structure and is suitable for microfabrication. For example, in addition to winding a conductor wire, 1. After forming a conductive layer on the surface of a non-magnetic bobbin such as alumina porcelain by plating, etc., the surface of the bobbin is subjected to mechanical precision grinding, photo etching, or laser beam processing, etc. It is also possible to form a single-layer solenoid-like inductance element by other means, and the cross-sectional shape of the conductor such as a conductor wire can also be arbitrary. Furthermore, the capacitive element 7 can also be easily formed with a dielectric material and an electrode on the inductance element 3 by high-speed sputtering or the like.

Furthermore, in the delay line of the present invention, if a fixed contact array is formed on a conductor strip on a non-magnetic bobbin and a movable contact is slid on this, an ultra-high-speed variable delay line can be obtained. The delay line of the present invention has a rise time In
The delay characteristics, which had reached their limit near s, have been dramatically improved, achieving faster delay characteristics and a smaller, more dense structure.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams explaining the present invention in detail and their equivalent circuit diagrams, FIG. 3 is a diagram explaining the coupling relationship between conductors in the inductance element shown in FIG. 1, and FIG.
The figure is a characteristic diagram showing the relationship between the ratio of the winding diameter T to the pitch P and the coupling coefficient in an inductance element, FIG. 5 is a partial plan view and side view showing a positive embodiment of the delay line of the present invention, and FIGS. FIG. 8 is a partial cross-sectional view and a side view of another embodiment of the delay line of the present invention, and FIG. 7 is a diagram showing an embodiment of the bobbin used in the inductance element of the present invention. 1...Bobbin 2, 2'...Conductor (conductor wire, conductor strip) 3...Inductance element, 7...
... Capacitive element, P ... Pitch, ■ ...
... Winding diameter in the short diameter direction of the bobbin, a++..., ayu...
... Coupling coefficient patent applicant Elmec Co., Ltd. Ya 1 Figure (A) CB) Ya 2
Figure 3 Figure 5 Figure 6 Figure 8 Figure 1'

Claims (5)

[Claims] (1) Form a single-layer solenoid-like inductance element with a pitch P having a space with a conductor, insert and connect a capacitor between the conductor and the ground for each turn of this inductance element, and connect the inductance element with a pitch P of the inductance element. and the winding diameter T in the minor axis direction is 0.2 (P / T (
A delay line set in the relationship 1,9. (2) Claim 1, characterized in that the conductor of the inductance element is formed on a non-magnetic bobbin.
Delay line as described in section. (3) The delay line according to claim 1, characterized in that the interface element has an air-core self-supporting configuration. (4) Claim 1 or 2, characterized in that the inductance element is formed in an annular shape.
Delay line as described in section. (5) The delay line according to claim 4, wherein the conductor of the inductance element is formed in a toroidal bobbin.