JPH044771B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a distributed constant electromagnetic delay line that handles ultra-high-speed signals with a rise time of 1 ns or less, for example, and in particular, the present invention relates to a distributed constant electromagnetic delay line that handles an ultra-high-speed signal with a rise time of 1 ns or less, and in particular, the present invention relates to a distributed constant electromagnetic delay line that handles an ultra-high-speed signal with a rise time of 1 ns or less. This paper relates to improvements in distributed constant electromagnetic delay lines using impedance lines facing each other.

[Conventional technology]

This type of distributed constant electromagnetic delay line is constructed by covering the outer periphery of an elongated plate-shaped ground electrode with a dielectric material to form a flat and elongated bobbin, and then winding a conductor around the outer periphery of this bobbin in the form of a single-layer solenoid. There is a configuration in which a conductive path is formed and this conductive path is opposed to the ground electrode.

Such a distributed constant type electromagnetic delay line can easily obtain good delay characteristics for ultrahigh-speed signals, but the present invention is a further improvement.

[Problem that the invention seeks to solve]

The present invention has been made under these circumstances, and is intended to provide a distributed constant electromagnetic delay line with improved output waveforms, especially rising waveforms.

[Means for solving problems]

In order to solve these problems, the present invention
Equipped with a flat conductor line in which a conductor is space-wound in the form of a single-layer solenoid, and a ground electrode placed on the dielectric so as to face the conductor line on the back surface side through a dielectric having the same thickness. A distributed constant type electromagnetic delay line in which the ground electrode is arranged to face a part of the conductive line of each turn, and the part of the conductive line that faces the ground electrode does not face the ground electrode. The ground electrode is arranged so that it is wider than the ground electrode.

[Effect]

In the present invention equipped with such a means, in each turn of the conductive line wound in a space in the form of a single-layer solenoid, the ground electrode has a part that does not face the conductive line, and in that part, there is no contact with the ground electrode. The capacitance between them decreases, and a portion with a relatively large inductance is formed independently in series in the middle of the conductive line.

〔Example〕

Examples of the present invention will be described below.

1 and 2 are a front view and a side view showing an embodiment of a distributed constant electromagnetic delay line of the present invention.

The outer periphery of the elongated plate-shaped ground electrode 1 is covered with a dielectric material 2 such as fluororesin, and a flat and elongated bobbin 3 is formed.

On the outer periphery of the bobbin 3, a plurality of rectangular unit conductive lines 5 having a length of one pitch and a bent part 4 in the middle are crimped in parallel so as to cross the axial direction C-C of the bobbin 3. Unit conductive lines 5 are connected in series to form a flat conductive line 6 space-wound in the shape of a single-layer solenoid. Reference numeral 7 indicates a connection portion between each of the unit conductive lines 5.

In the distributed constant electromagnetic delay line of the present invention, the ground electrode 1 located inside the flatly wound conductive line 6 is arranged to be shifted to one side in the width W direction of the bobbin 3. .

That is, as shown in FIG. 2, the ground electrode 1 is connected to the unit conducting line 5 on the opposite side (upper side in the figure) from the connection part 7.
The distance between the other end of the ground electrode 1 (lower end in the figure) and the connection part 7 is longer than the distance B between one end of the ground electrode 1 (the upper end in the figure) and the inner side of the bent part 8. The distance D between the inner sides is increasing. Note that the width A of the ground electrode 1 is sufficiently larger than the distance D.

Therefore, most of the unit conducting paths 5 on the front and back sides of each turn face the ground electrode 1 at substantially equal intervals via the dielectric 2 having substantially the same thickness, and are separated from the ground electrode 1 in the portions before and after the connecting portion 7. The structure is such that it does not confront this.

Such a distributed constant electromagnetic delay line of the present invention is
Since the ground electrode 1 is placed closer to the bent portion 8 of the unit conductive line 5 and left open on the connecting portion 7 side of the unit conductive line 5, as shown by the solid line in Fig. 3,
The rising part of the output pulse signal is the output amplitude.
Quickly stand up to 100% at a specified tilt.

The following may be considered as the reason why such an effect is obtained.

In other words, since the conductive line 6 is space-wound in a flat single-layer solenoid shape, if a portion of each turn that does not face the grounding electrode 1 is formed, as shown in the equivalent circuit of FIG. The conductor line of each turn is connected in series with a microstrip line DL which has a capacitance with respect to the ground electrode 1, and an inductance L which does not face the ground electrode 1 but has almost no capacitance with respect to the ground electrode 1. The configuration is as follows.

The unit conductor line 5 of each turn has mutual induction of M1, M2, ...Mn between the adjacent unit conductor line 5, one unit conductor line 5, ... n-th unit conductor line 5, respectively. In each turn, the part of the microstrip line DL is larger than the part of the inductance L, so it is assumed that mutual induction is formed between each microstrip line DL, and the part of the inductance L is Can be ignored.

However, if the inductance L is large, it may be included in the microstrip line DL.

Note that the mutual induction in Figure 4 shows only the one formed between the leftmost microstrip line DL and the microstrip line DL on the right side; There is mutual induction, and each microstrip line DL is similarly coupled to the left and right microstrip lines DL.

Considering the electrical characteristics of the distributed constant electromagnetic delay line when it is composed of only a microstrip line DL without inductance L, and when it is composed of a microstrip line DL and an inductance L, the fifth The result will be as shown in the figure.

That is, regarding the relationship between the output amplitude V and the frequency, in a distributed constant electromagnetic delay line without an inductance L, the output amplitude V decreases with a gentle slope as the frequency increases, as shown by the broken line in FIG.
On the other hand, in a distributed constant electromagnetic delay line that also includes an inductance L, the output amplitude V tends to be flat up to a certain frequency, and decrease relatively rapidly at frequencies above that.

In this case, when focusing on the cutoff frequency, the frequency is higher for the characteristic indicated by the broken line.

However, the cutoff frequency does not need to be higher than the passband where the rise time of the input pulse signal is required.In fact, it is better for the output pulse signal to have a flat amplitude characteristic in the range where the rise time of the input pulse signal is required. The waveform becomes good.

Therefore, if the cutoff frequency is within the range required by the rise time of the input pulse signal, the conductor line 6
By forming the microstrip line DL portion and the inductance L portion, it is possible to improve the rising waveform of the output pulse signal.

In the distributed constant type electromagnetic delay line of the present invention, the ratio of the dimensions B and D to the width W of the bobbin 3 varies considerably depending on their values. For example, the present inventor formed a conductor with a thickness of 0.07 mm and a width of 0.2 mm into a single layer solenoid shape with 40 turns at a pitch of 0.35 mm on a bobbin 3 with a width W of 5 mm. 2ns,
We created and experimented with a distributed constant electromagnetic delay line with a characteristic impedance of 100Ω.

Then, the dimension D is about 5% larger than the width W than B.
By increasing the value, the rise of the output amplitude V was improved by about 8%, and as shown by the solid line in FIG. 3 mentioned above, it was possible to quickly rise to about 100% of the output amplitude.

Also, the rise time of the output pulse signal is
Although an ultra-high speed of 200 ps was obtained, the slope of the rising part was almost the same in both cases, and the output waveform was improved in the present invention.

On the other hand, if D is matched to B in the width direction W of the bobbin 3, and the number of turns of the conductive path 6 is, for example, 30 or more, the rising waveform of the output pulse signal will be as shown by the broken line in FIG. It tends to rise slightly below 100% and then gradually reach 100%. This tendency becomes even stronger when the number of turns in the conductive line 6 is increased to increase the delay time, which is not preferable.

The distributed constant electromagnetic delay line of the present invention has a ground electrode 1
It is not limited to the case where D is placed closer to the bent portion 8 side of the conductive line 6, but it may be placed closer to the connecting portion 7 side of the unit conductive line 5 so that D<B.

In addition, the dimensions B and D with respect to the width W dimension of the bobbin 3
The ratio, that is, the ratio at which the ground electrode 1 is moved to one side, may be selected to an optimal value depending on the configuration of the distributed constant electromagnetic delay line and the desired characteristics.

Alternatively, as shown in FIG. 6, the center portion of the bobbin 3 in the width W direction may be removed and the two ground electrodes 9a, 9b may be arranged along the longitudinal direction so as to face each other.
Although the distributed constant electromagnetic delay line having this configuration tends to have a slight increase in pre-cut, it is possible to achieve the object of the present invention.

Furthermore, as shown in FIG. 7, the distributed constant electromagnetic delay line of the present invention has a single-layer solenoid-shaped conducting path 6 as shown in FIG. and the outer periphery is dielectric 1
1, and a configuration is also possible in which the ground electrode 12 is covered so as to face the conductive line 6 except for the front and back of the connection part 7.

In this way, the present invention aims to improve the output waveform in the flat conductive line 6 space-wound in the form of a single-layer solenoid. Moreover, the ground electrode 1 may be arranged so that the portion of the conductive path 6 facing the ground electrode 1 is wider than the portion not facing the ground electrode 1.

In the distributed constant electromagnetic delay line of the present invention, in order to adjust the characteristic impedance of the conducting line 13, in particular, to increase the characteristic impedance,
As shown in FIG. 8, it is also possible to form a large number of thin slits 14 in the ground electrode 1 in a distributed manner.
Here, a continuous conductor is wound into a single-layer solenoid shape.

The slits 14 dispersedly formed in the ground electrode 1 in this configuration reduce the capacitance and increase the characteristic impedance over the entire conductive line 13, and as in the present invention, the slits 14 are formed in a microstrip in each turn. Inductance L separate from the conductor line
This is different from the one in which the microstrip line is formed in series with the microstrip line.

〔Effect of the invention〕

As explained above, in the distributed constant electromagnetic delay line of the present invention, a flat conductor path made of a conductor space-wound in the form of a single-layer solenoid is connected to a ground electrode via a dielectric material of the same thickness on the front and back sides. In the opposing distributed constant electromagnetic delay lines, the grounding is done so that it faces a part of the conductor line of each turn, and the part of the conductor line that faces the ground electrode is wider than the part that does not face the ground electrode. Because the electrodes are arranged, at each turn of the conductor line, a part with approximately only inductance L is formed in series with the microstrip line, and the flat range of the amplitude characteristic with respect to frequency is expanded, and the output waveform, especially The rising waveform is improved.

[Brief explanation of drawings]

1 and 2 are front and side views showing one embodiment of the distributed constant electromagnetic delay line of the present invention, and FIG. 3 is a front view and a side view showing an embodiment of the distributed constant electromagnetic delay line shown in FIG. Figure 4 is an equivalent circuit diagram of the distributed constant type electromagnetic delay line (not shown) shown in Figure 1.
6 to 8 are side views and front views showing other embodiments of the present invention. 1, 9a, 9b, 12...ground electrode, 2, 11
...Dielectric material, 3, 10... Bobbin, 5... Unit conducting line, 6, 13... Conducting line, 7... Connection part, 8...
...Bend portion, 14...Slit, DL...Microstrip line, L...Inductance.

Claims (1)

[Scope of Claims] 1. A flat conductive path formed by space-wound conductors in the form of a single-layer solenoid, and arranged on the dielectric so as to face the conductive path on the front and back sides through a dielectric having the same thickness. a distributed constant electromagnetic delay line comprising: a ground electrode arranged to face a portion of the conductive line of each turn; and a portion of the conductive line opposite to the ground electrode. The distributed constant electromagnetic delay line is characterized in that the ground electrode is arranged such that the ground electrode is wider than a portion not facing the ground electrode.