KR20060124747A - An improved tuneable delay line - Google Patents

Abstract

A tunable electromagnetic delay line, comprising a first conductor with a first main direction of extension, said first conductor being arranged on top of a non-conducting substrate, characterized in that the delay line additionally comprises a layer of a ferroelectric material with first and second main surfaces, which layer separates the first conductor and the substrate, and in that the delay line also comprises a second conductor with a second main direction of extension, with the first and second main directions of extensions essentially coinciding with each other, and with the first and second conductors being each other's mirror image with respect to an imagined line in the center of the delay line along said first and second main directions of extension, said tuning being accomplished by applying a voltage between said first and second conductors.

Description

Improved Adjustable Delay Line {AN IMPROVED TUNEABLE DELAY LINE}

The present invention relates to an adjustable electromagnetic delay line comprising a first conductor having a first major stretching direction, wherein the first conductor is disposed on top of the nonconductive substrate.

Delay lines are a common component in many current electrical systems, mainly microwave systems. Examples of the art in which delay lines are used are radar systems, amplifiers, and oscillators.

Most of the technologies used in delay lines make the components huge, which is often not cost effective and difficult to integrate into standard semiconductor technology. Moreover, it is highly desired that the delay line be adjustable, i.e. have a delay time that can be changed. In addition, most current adjustable delay lines consume a lot of power, a major drawback.

Therefore, as described above, there is a need for an adjustable delay line that is useful for being compact, consuming less power, and having a longer delay time.

This need is met by the present invention which discloses an adjustable electromagnetic delay line comprising a first conductor having a first major stretching direction, wherein the first conductor is disposed on top of the nonconductive substrate.

The delay of the present invention additionally includes a layer of ferroelectric material having a first and a second major surface, which layer is separated into a first conductor and a substrate. The delay line also includes a second conductor having a second major stretching direction.

It is essential that the first and second major stretching directions coincide, and that the first and second conductors are symmetrical with respect to the imaginary line in the center of the delay line along the first and second major stretching directions. Delay line adjustment of the present invention is accomplished by applying a voltage between the first and second conductors.

The advantages provided by this design will become apparent in the detailed description given below.

The invention will be described in detail below with reference to the drawings.

1 is a top view of a first embodiment of the present invention;

2 is a cross-sectional view along line II-II for the device of FIG. 1, FIG.

3 is a top view of a second embodiment of the present invention;

4 is a cross sectional view along line III-III for the device of FIG. 3;

5 is a top view of another embodiment of the present invention;

6 is a cross-sectional view along line VI-VI for the device of FIG. 5, and

7-12 are top views of several different embodiments of the present invention.

1, a first embodiment 100 of an adjustable delay line according to the present invention is shown in a top view. Delay line 100 includes a first conductor 110 having a first major stretching direction, indicated by arrow A in FIG. 1. In addition to the first conductor 110, the delay line 100 also includes a second conductor 120 having a second major stretching direction.

Turning now to FIG. 2, along the line II-II in FIG. 1, a cross-sectional view of the device from FIG. 1 is shown. As shown in FIG. 2, the first and second conductors 110 and 120 are disposed on top of the ferroelectric material layer 130 having a high dielectric constant. Several examples of such materials are BaTiO ₃ , SrTiO ₃ and various compounds of TiO ₃ represented mainly by Ba _x Sr _(1-x) TiO ₃ , but mainly Na _x K _(1-x) NO ₃ . Represented are Na, K and NO ₃ compounds.

Under the ferroelectric material layer 130, a support layer or substrate 240 made of a non-conductive material is disposed. In Fig. 2, it is also schematically shown how the delay T of the device 100 is changed: AC control voltage V _TUNE is applied between the first and second conductors 110, 120 and the voltage is the desired delay. Changed to achieve (T). The fact that there is a capacitive connection between two conductors 110 and 120 is indicated by a dashed line in FIG. 2.

1 again, in the delay line 100 of the present invention, the first major stretching direction A of the first conductor 110 coincides with the second major stretching direction B of the second conductor 120 and It is also essential that the first and second conductors 110, 120 are shown to be symmetrical with respect to the imaginary line C at the center of the delay line along the first and second major stretching directions.

Preferably, as also shown in FIG. 1, the first conductor 110 is wavyly formed, and optionally includes a section 111 having a second stretching direction and a section 113 having a third stretching direction. . The second conductor 120 includes a section 112 having a fourth stretching direction and a section 115 having a fifth stretching direction.

According to the invention, it is essential that the second and fourth stretching directions coincide, and the second and fourth stretching directions also coincide.

In the embodiment shown in Fig. 1, it is essential that the second and third stretching directions of the first conductor are perpendicular to each other, and the second stretching direction coincides with the first main stretching direction of the first conductor. Due to the curved form of the embodiment shown in FIG. 1, this means that both the first and second conductors have a section in the general direction of the device, ie towards the "straight ahead". The result is perpendicular to the general orientation of one device. Two conductors change this section, which in this embodiment results in a curved type of conductor.

As mentioned above, and also as shown in Figure 2, there is a capacitive connection between the two conductors of the device.

Another embodiment 300 of the present invention is shown in FIG. 3. This embodiment is more flexible to suit the impedance of the device. The device 100 of FIGS. 1 and 2 includes an inductor in the form of a bent line, but only has a potential capacitive connection between the bent lines. In contrast, embodiment 300 has a capacitor represented by a dashed line in FIG. 3, the cross section in the cross section of FIG. 4 along the line IV-IV in FIG. 3.

As shown in FIGS. 3 and 4, the embodiment 300 includes the first and second conductors 320 in the same bent form as the embodiment 100 in FIGS. 1 and 2. However, in an embodiment, it additionally includes a third conductor 350 disposed between the nonconductive substrate and the ferroelectric material layer, wherein the third conductor is disposed so that it extends from a point below the first conductor to a point below the second conductor. , It is essential that the stretching direction is perpendicular to the first and second stretching directions.

Preferably, the third conductor 350 is disposed below the first and second conductors 310, 320 at a point below the first and second conductor sections indicating the general direction A / B of the device 300, and thereafter. The third conductor is disposed so that it connects to the first and second connectors, wherein the term “connecting” here wherein at least a first part of the third conductor is located below the first conductor and at least a second part of the third conductor is 2 used under the conductor. Thus, a capacitor is formed between each of the first and second conductors and the third conductor.

Such third conductors are suitably disposed at all or most of these positions within the apparatus 300, which satisfy the conditions described above for the position of the third conductor 350. Therefore, the device 300 of the present invention represents a number of such conductors, all located at corresponding places within the device 300.

Delay adjustment of the delay line 300 is accomplished by applying a DC voltage between the first and second conductors 310 and 320, as shown in FIG.

Another embodiment 500 in accordance with the present invention is shown in FIGS. 5A-5C. This embodiment illustrates a method of monitoring resistive losses: The first conducting pattern, delay line 505 shown in FIG. 5C, is formed between the lower layer of the device, ie, the substrate and the ferroelectric material, the first delay line. It is essential that 505 is similar to that shown in Figures 1 and 3, i.e., it has two curved forms of conductors 510,520, which are parallel to each other and extend in a common common direction, which conductors It is important to be symmetrical with respect to the virtual line C in between, which extends in the general direction of the device.

Therefore, the two conductors of the delay line 505 are directed “right ahead”, ie one section 532 in the general direction of the device and one section 531 perpendicular to the general direction C of the device 500. Has Both conductors 510 and 520 allow this section to be changed so that each section is associated with the next section. Therefore, each conductor has a repeating pattern of two parallel sections 531,534 facing "outside" with respect to the general direction of the device, wherein the two parallel sections are perpendicular to the two parallel sections. By the "outer" edge of the device. Each of these two parallel sections 531,534 are then connected to these sections adjacent to each other by their conductors 533, again perpendicular to the direction of the sections parallel to each other, the “inner end” of the crooked pattern.

As shown in FIG. 6, which is a cross-sectional view along line IV-IV of the device of FIG. 5, the device also includes a second conducting pattern 510 disposed on top of the ferroelectric layer. The second conducting pattern is shown in top view in FIG. 5B: The second conducting pattern is similar to the first conducting pattern except that it does not show a connecting conductor 533 at the “inner end”.

In device 500, the first and second conducting patterns are placed so that the corresponding sections are "covered" with each other, resulting in the device shown in FIG. 5A. As shown in FIG. 5B, the second conducting pattern 510 also represents conducting strips 512 that “connect” to the connecting strip at the “inner edge” of the first conducting pattern, ie In the second conducting pattern, the connecting strips 512 are arranged in a direction perpendicular to the general direction of the device, in order to cover or connect one connection strip to each bent line of the first conducting pattern. To stretch.

Although the delay lines shown in Figures 1-5 described above have several positive characteristics, there is any positive inductor strip, i.e., a negative coupling between the bent lines, which reduces the total inductance of the device. This negatively affects the latency of the device.

7 illustrates an embodiment 100 of the present invention that mitigates the problem of mutual negative coupling between strips: the apparatus includes first and second conducting patterns 710 and 720, arranged on different sides of the ferroelectric layer. do. Each conducting pattern optionally includes a section disposed at 45 degrees with respect to the general direction (c) of the device or a section disposed at minus 45 degrees. However, if the first section 721 of the first conductor is placed at 45 degrees, the first section 713 of the second conductor will be placed at minus 45 degrees, and the sections with two conductors placed in different directions cross each other. Shout Due to this shape, the sections traverse 90 degrees to each other and it is essential that the negative magnetic connection between the strips is removed.

In a more general sense, the embodiment shown in FIG. 7 can be described in the following way: The first conductor 710 optionally includes sections 712, 711 in the second and third stretching directions. 2 The stretching direction is α angle with respect to the main stretching direction C of the device, the third stretching direction is β angle with respect to the main stretching direction C of the device, α is an interval between 0 and 90 degrees, and β Is an interval between 90 and 180 degrees.

Second conductor 720 also includes sections 713 and 714 in the fourth and fifth stretching directions, wherein the fourth stretching direction is an α ′ angle with respect to the main stretching direction C of the apparatus, and the fifth stretching direction is the apparatus. Is the β 'angle with respect to the main elongation direction (C). α 'is an interval between 0 degrees and minus 90 degrees, and β' is an interval between negative 90 degrees and minus 180 degrees.

The first and second conductors 710 and 720 are disposed in the delay line 700 such that the section 712 of the second conductor in the second stretching direction crosses the section 713 of the second conductor in the fourth stretching direction, The section 711 of the first conductor in the third stretching direction crosses the second conductor section in the fifth stretching direction 714.

Figure 8 shows a version 800 of the device of Figure 7: In this embodiment, the two strip sections 810, 820 do not cross each other, but rather they are at the point where two adjacent sections in each conductor are connected to each other. Within each layer will match or "cover each other." One such point 815 is circled in FIG. 8 to clarify.

Although the versions of the present invention shown in Figures 1-8 described above show excellent characteristics for broadband applications, Figure 9 shows a method for achieving better broadband characteristics: While adhering to the basic design of Figure 7, The width becomes thinner.

By selectively tapering the device as shown in FIG. 9 and as shown in FIG. 10, the device can be periodically tapered and again widened to the same dimensions tapered.

In Figures 11A and 11B, a variant of the invention is shown which allows a good possibility of fitting the capacitance of the device: In this variant of the invention, there are also two conducting lines 1110 and 1120, It is located on each side of the ferroelectric layer supported by the non-conductive substrate, and lines 1110 and 1120 also have sections that cross each other at an angle of 90 degrees, preferably as in the case of FIG. However, in this variant in which the sections cross each other, one of the sections is preferably modified to have a hole, such as a square shape or to have a significantly narrower width during all or most intersections.

12A and 12B show top views of components of another embodiment 1200 of the present invention, and FIG. 12C shows embodiment 1200 as a whole of the top view. This embodiment can provide additional losses and increased processing tolerances and uses capacitances that reduce floating bias in the center while reducing the required bias voltage.

Fig. 12A shows the bottom layer and Fig. 12B shows the top layer, where the two layers are conductive and separated in the same way as the conductors in the embodiment shown in Figs. 7-11.

The lower conductor 12a and the upper conductor 12b are of the same design, and the separating layers mentioned therebetween are arranged at the "top of each other" in such a way that the corresponding parts in each conductor "cover" each other. . Each conductor comprises two curved patterns of conductors, arranged symmetrically between the conductors with respect to an imaginary line extending in the direction of the conductor. Therefore, each curved pattern will have sections parallel to each other that extend perpendicular to the general direction of stretching of the conductors and sections that are parallel to each other, which have directions of stretching that match the general direction of stretching of the conductors, the two types of sections being It changes to a bent pattern. Therefore, in each of the bent lines, among these sections having an elongation direction that matches the general elongation direction of the conductor, there are sections, which are closest to some bent line and this section is furthest from the other bent line.

In order to achieve the desired capacitive connection, in the lower conductor, every other "closest" section includes a protrusion facing another bent line, with the thin line ending with the protrusion, and all other closest sections being slightly of the thin line. It includes a recess to allow the intrusion of.

In the upper conductor, the "closest" section corresponding to this closest section in the lower conductor, with the recess, comprises a square or square hole that "surrounds" the penetration of a thin line, even on another plate of the device. This will enhance the manufacturing tolerances of the device.

Claims (7)

In an adjustable electromagnetic delay line (100,300), comprising a first conductor (110,310) having a first major stretching direction (A), the first conductor being disposed on top of a nonconductive substrate (240, 340). The delay lines 100 and 300 additionally comprise ferroelectric material layers 130 and 330 having first and second surface layers, which layers are separated into first conductors 110 and 310 and substrates 240 and 340, the delay lines being It also includes a second conductor (120,320) having a second major stretching direction (B), wherein the first and second major stretching directions coincide with each other, the first conductor (110,310) and the second conductor (120,320) Are symmetrical with respect to the imaginary line C in the center of the delay line along the first and second main stretching directions A and B, the adjustment being achieved by applying a voltage between the first and second conductors. Adjustable electromagnetic delay line, characterized in that. The method of claim 1, The first conductors 110 and 310 optionally include a section having a second extension direction and a section having a third extension direction, and the second conductors 120 and 320 optionally have a section having a fourth extension direction and a fifth extension. And a section having a direction, wherein the second and fourth stretching directions coincide with each other and the third and fifth stretching directions coincide with each other. The method according to claim 1 or 2, And further comprising a third conductor 350 disposed between the substrate and the ferroelectric material layer, the third conductor extending from a point below the first conductor to a point below the second conductor, 2 Adjustable electromagnetic delay line, arranged to be perpendicular to the stretch direction. The method of claim 2, And the second conductor (505,710) is disposed between the ferroelectric layer and the substrate such that first and second conductors face the major surface of the ferroelectric layer. The method of claim 4, wherein The second stretching direction 712 of the first conductor is α angle with respect to the first main stretching direction, and the third stretching direction 713 of the first conductor is β angle with respect to the first major stretching direction C. , α is an interval between 0 and 90 degrees, and β is an interval between 90 and 180 degrees. The method according to claim 4 or 5, The first and second conductors 710 and 720 may include a section 712 of the first conductor in the second extension direction crossing the section 713 of the second conductor in the fourth extension direction and the third And the section (711) of the first conductor in the stretching direction is disposed in the delay line to cross the section (714) of the second conductor in the fifth stretching direction. The method according to claim 4 or 5, The first and second conductors 810 and 820 have a point 815 where sections of the first conductor in the second and third directions meet, and a third section where the sections of the third conductor in the third and fourth extension directions meet. An adjustable electromagnetic delay line arranged in said delay line so as to overlap a point of a conductor.

Images