Patent ID: 12218713

DETAILED DESCRIPTION

FIG.1shows the signal conductor10of a conductor track arrangement1having a deflection by 90° in relation to the previous and the new propagation direction in a deflection area4, or a deflection area having an inclination of the outer edge. The conductor track-shaped or layered signal conductor10has an outer edge2and an inner edge3. In the deflection area4, the outer edge2bends by a deflection angle of 45° in relation to the previous propagation direction, so that the contour of the conductor has an inclination8.

If the signal conductor10, as shown inFIG.1, has a width W, an angular connection thus has a width D of the signal conductor10along the mirror axis, which results due to the inclination by a value X, and as a result of the described formation of the deflection, an inclination X arises. According to the cited source from Agilent Technologies, the following applies for the optimal inclination:

XD=0.5⁢2+0.6⁢5×e-1.3⁢5×WH
H designates the thickness of the conductor track here. The following obviously applies for D: D=√2×W

For typical dimensions of W=500 μm and H=150 μm, the following is obtained for the inclination X:
X=372.8 μm

This is used hereinafter as the reference model.

FIG.2shows an example of a signal conductor10of a conductor track arrangement for high-frequency signals according to this disclosure. The signal conductor10is formed in general as a flat, in particular layered conductor, for example in the form of a conductor track. As inFIG.1, the signal conductor10is shown in a top view. The elongated signal conductor10has a deflection area4, which connects two legs13,14and in which the signal conductor10changes its direction. Due to the direction change, the legs13,14are at an angle to one another. As also in the example ofFIG.1, the direction change is 90°. The signal conductor10is delimited by two edges2,3. One of the edges, namely edge2, forms an outer edge, the other edge3is an inner edge. An outer edge is defined in that the direction change of the signal conductor10leads it away from the outer edge. At the inner edge, the direction change has the result that a straight line laid on the inner edge intersects the signal conductor10in the deflection area4. In other words, the contour of the outer edge2is overall convex in the deflection area, the contour of the inner edge3is overall concave.

The example ofFIG.2is based on an embodiment in which the outer edge2has two deflection sections5, which are at an angle to one another. In particular, the deflection sections5are preferably linear or slightly curved.

According to a further, general embodiment, which is also implemented in the example ofFIG.2, at least two deflection sections5are connected by a corner12. The deflection sections5are at an angle to one another due to the corner. According to still a further embodiment, also implemented in the example ofFIG.2, the respective edge2or3emerges via a corner12into a deflection section5. A corner as a punctiform structure in the mathematical meaning is not possible in the structuring of real conductor tracks. A corner is therefore understood more generally as a section of the edge2or3, the length of which is at most 1/10 of the length of the shorter of the adjoining deflection sections5.

The signal conductor10according toFIG.4has three deflection sections5at the edge2in the deflection area4, wherein the edge2forms the outer edge. The other edge3, which forms the inner edge, has no deflection sections5as in an example shown inFIG.3. Overall, a change of the line direction by 90° results. The deflection sections5are each inclined by various angles in relation to one another.

In the embodiment shown inFIG.3, the signal conductor10has at least one curved deflection section5,6in the deflection area4, and thus in particular no straight or angled deflection sections at the respective edge2,3which has the curved deflection section. In the embodiment shown, the inner edge3, that is to say in particular at least one deflection section6of the inner edge3, is formed curved. However, multiple deflection sections, which are at an angle to one another, for example, can also be curved. This curved deflection section5or these curved deflection sections5can be located at the inner edge2and/or at the outer edge2. In general, without restriction to the examples shown in the figures, the inner edge2and/or the outer edge2can have deflection sections. In other words, deflection sections5can only be arranged at the outer edge2, for example, or only one edge, for example the outer edge2, has to be modified or optimized to promote improved return loss.

In addition, in general according to still a further embodiment, as in the example ofFIG.4, the deflection sections5can have different lengths. In contrast to the embodiments previously shown, in the example shown inFIG.5, deflection sections6are provided at the edge3, which forms the inner edge.

Furthermore, it is possible according to one embodiment that at least one deflection section5,6is inclined or extends counter to the deflection direction of the signal conductor10. This embodiment is also implemented in the example shown inFIG.5. In this example, these are the two inner deflection sections6, in particular two inner deflection sections6are opposite to one another.

In the example shown inFIG.6, deflection sections5are also provided which extend counter to the deflection direction, but at the outer edge here. In the example, these are every second deflection section5. In the example, the edge3is formed in the deflection area4by multiple short deflection sections5arranged at right angles to one another, so that a stepped formation results at the outer edge. Overall, six deflection sections are provided in the deflection area4. Overall, a change of the signal conductor10by 90° results.

In the example shown inFIG.7, both edges2,3have deflection sections5,6. In addition, more than two deflection sections5,6, namely three deflection sections5,6in each case, are provided at each of both edges2,3. However, more than three deflection sections5,6can also be provided, preferably at the outer edge2or the inner edge3, in particular in such a way that a large number of deflection sections5,6approximates a curved edge.

FIG.8shows an example of a particularly preferred embodiment of the conductor track arrangement according to the invention, or of the signal conductor10of the conductor track arrangement. This embodiment is based on the deflection area4being formed asymmetrically. In particular, a mirror axis is not provided as a line of symmetry. In contrast thereto, for example, the deflection area of the example ofFIG.2has a mirror axis along the angle bisector38of the deflection angle, in particular the edge3. While the inner edge3of the signal conductor10has no deflection sections in the deflection area4, the outer edge2has two deflection sections5of unequal length in the deflection area, wherein the edge from the leg13to the first deflection section5has a direction change by a deflection angle α. In the illustrated example, this direction change or the deflection angle α is approximately 16°. In general, without restriction to the illustrated example, it is provided here according to still another embodiment that the direction change or the deflection angle at one edge2,3, preferably at the outer edge2at the transition from one leg13,14to the adjoining deflection section5, is less than 45°, preferably less than 40°.

Preferred configurations of conductor track arrangements1are shown inFIGS.9to11. One example of a particularly preferred configuration is shown inFIG.9. The signal conductor10and the ground conductor11are arranged on opposite sides of the carrier16. Such a configuration is known in principle to a person skilled in the art as a so-called microstrip line. In general, the carrier16can be a submount17. Such a submount can be arranged on a socket of a housing for an electronic component. In particular a socket for a TO housing (TO=transistor outline) is considered here. The shape of the signal conductor10having two deflection sections at the outer edge corresponds to the example ofFIG.2.

The submount17can be manufactured, for example, from aluminum nitride ceramic, more generally a ceramic containing aluminum nitride, or aluminum oxide (Al2O3). Other materials having good thermal conductivity can also be used, for example glass or glass and ceramic. A submount17made of glass can also be used for the high-frequency line. Particularly thin glass can be suitable due to the low thickness. At thicknesses of the submount less than 0.2 mm, for example, the significantly worse thermal conductivity can be partially compensated for. The so-called thermal resistance is decisive. The thinner a substrate, the lower is its thermal resistance.

The configuration ofFIG.10is based on the signal conductor10and the ground conductor11being arranged on the same side of the carrier16. The signal conductor10extends here in a gap18in the ground conductor11. The example thus represents a coplanar conductor track arrangement (CPW=“coplanar waveguide”).

FIG.11shows a variant of a coplanar conductor track arrangement1. In this case, in addition to the conductor tracks of the ground conductor11arranged coplanar to the signal conductor10, a conductor track of the ground conductor11arranged on the opposite side of the carrier16is also provided. Such an arrangement is designated as a CBCPW (“conductor backed coplanar waveguide”). All exemplary embodiments share the feature that the deflection takes place in at least two steps.

A comparison of the return loss of a conductor track arrangement according to this disclosure to other arrangements is explained hereinafter. For this purpose,FIG.12shows the return loss computed using a simulation computation as a function of the signal frequency for three different arrangements.

Curve (a) inFIG.12shows the return flow for a deflection area which is provided with a rounded outer edge. The largest possible bandwidth is achieved here when the radius of curvature is wider than the conductor track, thus when the following applies:

Radius⁢of⁢curvatureWidth⁢of⁢the⁢conductor⁢track⁢strip≥1

Curve (b) is the return loss for a deflection area having a single 45° inclination, thus a deflection area as shown in the example ofFIG.1.

Curve (c) shows the return loss at an asymmetrical two-step deflection according to this disclosure, thus an example similarly as in the signal conductor10according toFIG.8. The deflection angle α between the edge at the leg13and the first deflection section is 30° here. The signal flow direction is from the leg13via the deflection area4into the leg14. The width10of the signal conductor tracks10at the legs13,14is 0.6 mm in all examples.

As is apparent on the basis ofFIG.12, the return loss of the conductor track arrangement1having two deflection sections5and asymmetrical deflection area, in a broad frequency range from 10 GHz to 50 GHz, is significantly lower than in the comparative arrangements.

The influence of the deflection angle α of the deflection section5on the adjoining edge of the leg13is discussed on the basis ofFIG.13.FIG.13shows for this purpose the return loss in dB as a function of the signal frequency for various deflection angles α of the deflection section5. The curves are designated with the respective deflection angle, which varies between 28° and 32°. For comparison, a curve for an arrangement having a single 45° inclination, thus an arrangement according toFIG.1, is also shown. This curve is identified by the designation “45°”.

The conductor track arrangements were based on the following model parameters: The carrier on which the conductor track arrangement designed as a microstrip is applied consists of aluminum nitride ceramic having a permittivity of 8.8. The dielectric loss factor tan(□) is 0.001. The conductor tracks, in particular the signal conductor10, are manufactured from gold. The conductivity of the gold conductor track is 41000000 Siemens/m.

As is apparent on the basis of the curves, the single 45° inclination displays the highest losses. At high signal frequencies between 30 GHz and 45 GHz, the arrangement having a deflection angle of 30° displays particularly low loss.

As is apparent inFIG.13, the magnitudes of the dispersion parameter S11, thus in particular of the return loss, are particularly low. All curves are below −15 dB, even below −20 dB, so that according to one embodiment of the invention without restriction to the examples shown, it is generally provided that the deflection area4is formed so that the absolute value mag(S11), or the magnitude of the dispersion parameter S11over the observed frequency range, in particular from 1 GHz to 50 GHz, is less than −15 dB, preferably less than −20 dB, preferably less than −25 dB.

To be able to assess the angle dependence of the reflection loss in the entire high-frequency range, the losses mag(S11(f)) for frequencies fnin the range from 1 GHz to 50 GHz were summed:

S=∑fn=1⁢GHz50⁢GHzmag⁡(S11(fn))(3)

The result of this summation is shown inFIG.14.FIG.14shows a diagram having the amplitudes summed in the frequency range from 1 GHz to 50 GHz in steps of 220 MHz, or absolute values mag(S11) of the return loss S11for the various deflection angles from 28° to 32°. The course of the curve shown displays a clear minimum for a deflection angle of 30°. The summed return loss at the deflection section according to equation (3) is less than 1000 at deflection angles in the range from 28° to 30°. Such values can also be achieved with other geometries of deflection areas having multiple deflection sections along an edge. Therefore, in general it is provided in one embodiment that the deflection area4is shaped so that the sum S of the dimensions of the dispersion parameter S11 for frequencies at the interval of 1 GHz according to equation (3) in a frequency range from 1 GHz to 50 GHz is less than 1000.

The following advantages are achieved by this selection of the deflection angles and unequal length of the deflection sections:

In comparison to a single 45° deflection according to the prior art, a better control of the capacitance of the corner of the conductor track in the deflection area is achieved. This increases the bandwidth of the signal used for data transmission. Due to the minimum around a deflection angle of 30°, it is generally provided according to one embodiment that the deflection angle of an edge2,3, preferably the outer edge3at the transition from one leg13,14of the signal conductor10to the adjoining deflection section5, is between 29° and 31°.

This disclosure also relates in general to electronic component parts which are installed in a housing and are connected to the conductor track arrangement described here to transmit high-frequency electrical signals. One part of the housing is typically a socket, on which the electronic component is fastened and via which the signal feed takes place. In general, for this purpose a socket20for an electronic component is provided with an electronic component part28and a conductor track arrangement1according to this disclosure, wherein the socket has an electrical feedthrough22, and wherein the electronic component part28and the electrical feedthrough22are both connected to the signal conductor10of the conductor track arrangement1, so that electrical signals are conducted from the feedthrough22via the signal conductor10to the component part28. In particular, feedthrough22and electronic component part are each connected to one of the legs13,14, so that the electrical signals flow in succession through one leg, the deflection area4, and then the other leg.

Furthermore, this disclosure also relates to an electronic component having a socket. The electronic component30is a component having a housing, in which the electronic component part28and the conductor track arrangement1are enclosed. In particular, the housing can comprise a socket20and a cap31.

FIG.15schematically shows an electronic component30having such a socket20. An optoelectronic converter is preferably used as an electronic component part28in the electronic component30. The electronic component part28can thus be a laser diode to convert high-frequency electrical signals for the optical signal transmission. Vice versa, the electronic component part28can also be a photodiode to convert optically transmitted data back into electrical signals.

The housing of the electronic component30can be, for example, a TO housing (TO=“transistor outline”). For an optoelectronic converter as an electronic component part28, the cap31connected to the socket20can have a window32. For example, the window32can be connected to the sheet-metal of the cap31by means of a glass solder.

Depending on the direction in which the signals are converted, a signal conduction direction is defined. In electro-optical converters such as a laser diode, the signal conduction direction is along the signal conductor10from the feedthrough22out to the laser diode. To achieve a good reflection loss, it is generally particularly preferred here, without restriction to the illustrated example, if the deflection section5adjoining the leg13through which the electrical signals flow first has a deflection angle of less than 45°, preferably less than 40°, to the edge, preferably to the outer edge3of the leg13. Which leg13,14the electrical signals flow through first is determined in this case by the signal conduction direction. Preferably, the leg13is the one through which electrical signals flow first as defined by the signal flow direction.

A deflection of the signal conductor10, as is described in this disclosure, can be advantageous, for example, if the electronic component part28is to be thermally decoupled from the socket20. For this purpose, it can be provided according to one embodiment that the electronic component28is arranged on a platform24, which is cooled using a thermoelectric cooler26, wherein the carrier16having the signal conductor10is arranged adjacent to the platform24and separated by a gap27from the platform24. The gap27prevents a thermal contact to the carrier16of the conductor track arrangement1. Due to this arrangement, however, the signal conductor then extends adjacent to the thermoelectric cooling element26and the platform. The deflection is then used to guide the signal conductor10in the direction to the electronic component part28, as is apparent on the basis of the example ofFIG.15.

The gap27can then be bridged using a bond wire29attached at one end of the signal conductor10, in particular at the end of the leg14. The electrical connection to the electronic component part28takes place as shown in the example from the feedthrough22to a first leg13of the signal conductor10, via the deflection area4to the second leg14up to the end of the signal conductor10, which is typically also the end of the second leg14, and from the end of the signal conductor10via the bond wire29. The bond wire29can directly contact the electronic component part29or can establish the connection to a further conductor track on the platform24. In the example shown inFIG.15, the electronic component part28is directly connected to the bond wire29.

It is apparent to a person skilled in the art that the conductor track arrangement1, as well as the socket20having the conductor track arrangement and the electronic component formed using the socket20, are not restricted to the specially illustrated examples. Thus, an additional leg can also join one or both legs13,14via a further deflection area. In this way, the signal conductor10can be U-shaped, for example, or the further leg extends laterally offset in parallel to the first leg. Furthermore, it is also conceivable to provide two or more signal conductors10on the carrier16. According to one embodiment, these signal conductors10can extend in a coplanar manner on one of the sides of the carrier16, wherein a common ground conductor is provided on the opposite side.

Signal conductors are known from the prior art in which both edges are curved, however, their cross-sectional widths of the conductor track do not change during the curvature, as is shown inFIG.16, for example. Due to the constant cross-sectional width, the curvature has an elevated capacitance, which changes the line impedance. A mismatch of the line is linked thereto, which results in a higher reflection loss of the signal in the curvature. This is avoided in that the width W of the signal conductor10changes in the deflection area4, by which the capacitance is adapted to the required impedance, in particular reduced.

FIGS.17aand17btherefore show a conductor track arrangement1having two curved edges, in which the signal conductor10is narrower in the deflection area4than at the ends of the signal conductor10. At the beginning, or at one end and at the other end of the line curvature, or of the deflection area4, in particular of the signal conductor10, the signal conductor10has the width W. The line is thus adapted at the beginning and at the end to the required line impedance. The width W preferably changes continuously over the angle of curvature of preferably 0° to 90°. The signal conductor10preferably has its minimum width Wminin the area of half the angle of curvature between 35° and 60°. In the case of an asymmetrical formation of the deflection area, the minimum width Wmincan also be located above 60° or below 35°, however. In the further course, the width W increases again, to reach the width W again at the end at 90°. In this way, a better transmission behavior at high frequencies is achieved in comparison to conductor tracks from the prior art, which is shown inFIG.16, for example.

The signal conductor10having two curved edges and a narrower width W in comparison to the ends in the deflection area can be designed differently. Preferably, the curvature of the inner edge3and the curvature of the outer edge2have an ellipsoidal or circular contour. It is therefore conceivable that the center point of the circle formed by the inner edge3is arranged closer to the signal conductor10than the center point of the circle formed by the outer edge2.

In this case, as shown inFIG.17a, the segment of a circle formed by the outer edge2can be less than 90°, or can preferably also be greater than 90°. Similarly, the angle between the inside of the outer edge2and a line defined by the width W of the signal conductor10at the beginning of the curvature of the outer edge2can have a value of 90° or less. The angle between the inside of the inner edge3and a line defined by the width W of the signal conductor10at the beginning of the curvature of the inner edge3can have a value of 90° or less. It is possible here that the beginning of the curvature of the outer edge2is arranged offset in the direction of the length of the signal conductor10in relation to the beginning of the curvature of the inner edge3, preferably in such a way that at least the outer edge and/or the inner edge3has at least one straight, in particular non-curved section in the deflection area4.

FIG.17bshows a different geometry of the signal conductor10, wherein the angle between the inside of the outer edge2and the line defined by the width W of the signal conductor10at the beginning of the curvature of the outer edge2has a value of 90° or more. The segment of a circle formed by the outer edge2is then less than 90° or preferably exactly 90°. The angle between the inside of the inner edge3and the line defined by the width W of the signal conductor10at the beginning of the curvature of the inner edge3can have a value of 90° or more. In this case, the segment of a circle formed by the inner edge3is greater than 90°, preferably greater than 130°, preferably greater than 180°. It can be conceivable that the beginning of the curvature of the outer edge2is arranged offset in relation to the beginning of the curvature of the inner edge3, preferably in such a way that at least the outer edge and/or the inner edge3has a straight, in particular non-curved section in the deflection area4.

FIG.18shows how a preferred width Wmincan be ascertained in the deflection area4. A construction is depicted having a conductor track as presented inFIG.16, having constant line width W in the line curvature in the deflection area4. Furthermore, an auxiliary circle34is shown. The center point of the auxiliary circle34is defined in that the distance of the circle center point to the outer contour or edge points33of the line curvature is equal at the beginning or one end35and at the other end36of the curvature or of the deflection area4. The two contour points33are circled by dashed lines. If the radius Rhof the auxiliary circle34is greater than the radius of the outer edge2of the signal conductor10, the auxiliary circle34cuts off a crescent-shaped area40from the line curvature. A preferred line curvature now results by subtraction of the crescent area40from the line curvature. The crescent area40consists of two circle segments of different radii. The distance of these two circle segments is zero at the angles of curvature 0° and 90° and is maximum at the angle of curvature of 45°. This means that at 0° and 90°, the line curvature is not cut. At the beginning35and at the end35of the deflection area4, the width W of the signal conductor10remains the same or unchanged. In particular at the angle of curvature 45°, in contrast, most of the line curvature is cut off. The width Wminof the signal conductor10is preferably minimal there.

Depending on the carrier material, the desired line impedance, and the curve radius of the line curvature, a matching radius Rhof the auxiliary circle34is ascertainable by simulations. This typically represents a compromise from the shift of the limiting frequency of the higher-order waves and the required reflection loss. However, it is also conceivable that instead of the auxiliary circle34, an ellipse or a parabola is used. However, it is important in this case that the auxiliary area is formed by a steady function to avoid abrupt changes in that the outer edge of the signal conductor10intersects the auxiliary surface at at least two points. On the basis of such simulations and their results, the advantage of the width Wminof the signal conductor10reduced in the deflection area4is to be proved hereinafter.

It is apparent on the basis ofFIGS.17a,17b, and18that a favorable form of the signal conductor10can be obtained without restriction to the specially illustrated examples if the outer edge and the inner edge represent segments of non-concentric curves, in particular non-concentric circles or ellipses. Accordingly, the curvature or the curve course of the inner edge3and the curvature of the outer edge each have a center, wherein the center of the curvature of the inner edge3and the center of the curvature of the outer edge are arranged offset to one another, in particular so that the curvature of the inner edge3and the curvature of the outer edge2are formed eccentrically. In particular, for this purpose the center of the curve of the inner edge3can be arranged closer to the signal conductor10than the center of the curve of the outer edge2. This is also the case in both configurations ofFIGS.17aand17b. In the examples, this offset of the centers lies along the angle bisectors38of the deflection, which in the case of outer and inner edges in the form of circular segments, results in a mirror-symmetrical shape of the deflection area with respect to the angle bisector38, preferably also of the entire signal conductor10.

InFIGS.19,21,23,25, and27, the insertion loss and inFIGS.20,22,24,26, and28the reflection loss of the 90° line angle known from the prior art having a 45° inclination8, as shown inFIG.1, and the line curvature having constant line width W fromFIG.16are therefore shown. The insertion loss and the reflection loss which can be achieved using the design according to the invention of the curvature of the signal conductor10in the deflection area4, wherein both edges2,3are curved and the width Wminof the signal conductor10in the deflection area4is less than the width W at the ends35,36of the deflection area4, are also shown. For better illustration and comparability of the diagrams, matching pictograms were introduced in each case, which show the respective one of the above-mentioned three designs of the signal conductor10using which the illustrated results were achieved. The pictograms correspond here to the embodiments of the signal conductor10shown inFIGS.1,16,17a, and17b.

FIGS.19to24show for this purpose the course of the dispersion parameters S21and S11describing the signal loss on a transistor outline header (TO header) having a signal line connected to a feedthrough. The line curvature according to the invention inFIGS.23and24shows significantly better properties at high frequencies than the line angle (FIGS.19and20) or curvature known from the prior art having constant line width W (FIGS.21and22). In the insertion loss, singular points mark the limiting frequencies for higher-order waves here. At the two known deflections of a signal line10, the lower limiting frequency is at approximately 65-70 GHz. In the case of the line curvature having reduced width Wminand curved edges2,3, the limiting frequency is advantageously at greater than 80 GHz, or is no longer in the measuring range. The limiting frequency is thus shifted toward significantly higher values by the reduced width Wminin the deflection area4and the curvature of the edges2,3, so that the fundamental wave is no longer impaired at relatively high frequencies by higher-order waves, as is possible with signal conductors from the prior art.

Since the line curvature with constant conductor track width W cannot compensate for the elevated capacitance of the corner, the reflection loss overall is greater than that of the 90° line angle with 45° inclination. In the case of the line curvature with reduced width Wminand curved edges2,3, however, the elevated capacitance can be compensated for very well and therefore also displays improved reflection loss in comparison to the 45° inclination8or the constant width W. The diagrams show that the line angle having 45° inclination8and the line curvatures having constant width is no longer to be used for undisturbed signal transmission above the limiting frequency.

To show the breadth of application of a signal conductor10having improved line curvature having reduced width Wminand curved edges2,3, the simulation was carried out using two different carrier circuit boards.

InFIGS.19to24and also the diagrams ofFIGS.25to28, the frequency profiles of the dispersion parameters for the various shapes of the signal conductors10are identified on the basis of the line representation. The frequency profiles on the known arrangement having a 45° inclination are each represented by a dotted line, the profiles on a curved signal conductor10having constant width W by a dashed line, and the profiles on a curved signal conductor10having variable width W by a solid line. In addition, the respective curves are identified by pictograms which represent the various conductor track shapes. InFIG.25, the insertion losses of the simulation results are shown, in which the simulation was carried out using a carrier circuit board or a submount17having a thickness or height of 0.2 mm.FIG.26shows the corresponding results of the reflection loss for the properties mentioned forFIG.25.

FIG.27shows the insertion loss using a submount17having a height of 0.15 mm.FIG.28shows the corresponding results of the reflection loss for the properties mentioned forFIG.27.

The simulations presented inFIGS.25,26and27,28accordingly differ in typical values of the height, or the thickness of the submount17and the width W of the signal conductor10, for an application in TO. It is clearly apparent inFIGS.25to28that the limiting frequency for the excitation of higher-order waves with a 45° inclination and a constant conductor track width W is already at approximately 70 GHz, wherein the limiting frequency upon use of a thinner submount17is between 80 and 100 GHz. The limiting frequency with a signal conductor10having reduced width Wminand curved edges2,3is significantly higher in all cases, in contrast. The limiting frequency is increased by approximately 20 GHz or more here. In the case of the thin submount, a very minor inflection in the insertion loss is recognizable at approximately 90 GHz, which indicates a limiting frequency that can be minimized to insignificance, however, by suitable selection of the width Wmin. Improved values are also clearly recognizable in the reflection loss in comparison to a 45° inclination and a constant conductor track width W.

FIG.29schematically shows a signal conductor10having reduced width Wminand curved edges2,3in use with a further electronic component having a socket20and its base21. An electronic component, preferably an optoelectronic converter, in particular a laser diode or a light sensor, can be provided as the electronic component part28, as is also described inFIG.15. The electronic component part28, without restriction to the example shown here, can be connected to two signal conductors10, which can each be electrically connected to a pin for further signal transmission. To achieve good reflection loss, it is generally advantageous if in each case one and35of the deflection area or the signal conductor10is electrically coupled to a pin and another end36is electrically coupled to the component part28. The deflection is typically used to lead the signal conductor or conductors10from the pin in the direction to the component part28.

The signal conductors10are preferably electrically separated or decoupled from one another, for example by a gap27. At least one signal conductor can preferably be electronically connected to the component part28using at least one bond wire. It is typically provided that the other signal conductor is coupled directly, in particular without a bond wire, to a terminal of the component part. A deflection of the signal conductor10, as is described in this disclosure, can be advantageous, for example, when the electronic component part28is to be thermally decoupled from the socket20, as shown inFIG.15. For this purpose, it can be provided that the component part28is arranged on a platform24, which is cooled using a thermoelectric cooler26. However, it is preferred, in contrast to the illustration inFIG.15, for the electronic component part28to be cooled without a thermoelectric cooler26and in particular to be thermally coupled to the platform24. Furthermore, a submount17or a carrier16is preferably arranged on the platform24, on the top of which the signal conductor or conductors10are arranged. On the bottom of the carrier16, in particular with electrical contact to the platform24, a ground conductor is arranged for the purpose of grounding, so that the conductor track arrangement1can be designed as a microstrip line or also as a CBCPW arrangement.

The conductor track arrangement1or the signal conductor or conductors10have a deflection area4, wherein the width Wminin the deflection area4is less at least in sections than the width W at at least one of the ends35,36of the deflection area4. The edges2,3, in particular the outer edge2and inner edge3of at least one signal conductor10, preferably both signal conductors10, are preferably curved at least in sections, in particular continuously. The curvature of the inner edge3and the curvature of the outer edge3is preferably formed eccentrically, so that the radius of the curvature of the outer edge2is greater than the radius of the curvature of the inner edge3. The deflection area4can extend from one end to the other end of the signal conductor or conductors.

To understand the mode of operation and in particular the effect of the above-described conductor track arrangement, the occurrence of higher-order waves on a microstrip line, as is described, for example, inFIGS.9and29, will be briefly explained hereinafter.FIGS.30a,30b, and30cshow for this purpose a microstrip line in cross section and the field lines42forming between the signal conductor11and the ground conductor11arranged opposite thereto on the submount17. The submount17has a height h, which is small in relation to ¼ of the wavelength. For this reason, no taller waves exist in the vertical direction. However, higher-order waves can be capable of propagating in the horizontal direction if the width W is in the order of magnitude of a multiple of half the wavelengths (n λ/2). In this case, further standing waves can form in the transverse direction. There is therefore a limiting frequency from which higher-order waves propagate or can exist. Higher-order waves can also be excited by disturbances of the signal conductor10.

The microstrip line has an inhomogeneous material filling and therefore does not carry solely transverse-electromagnetic waves (TEM wave). However, the fundamental waves behave over broad frequency ranges nearly like a TEM wave and are therefore also designated as quasi-TEM waves. These can be used well for signal transmission. In the case of these fundamental waves or quasi-TEM waves, the field lines of the electrical field (E field), as shown inFIG.30a, are directed in the same direction over the cross section of the signal conductor10or over the width W of the signal conductor10, thus are constant. The field lines of the higher-order waves change their direction in contrast over the width W of the signal conductor10, so that the E field disappears between such direction changes.FIGS.30band30cshow the field lines of the two first harmonics or higher-order waves for this purpose.

The fundamental waves and all higher-order waves are referred to as natural waves of the signal conductor10. On an undisturbed line, the natural waves move independently from one another and do not mutually interfere. In the event of interference, for example a direction change or a bend of the signal conductor, coupling of the natural waves occurs, thus the fundamental waves and the higher-order waves. The properties of the fundamental waves change in this way as soon as a higher-order wave propagates.

The above-described microstrip line has the advantage that it has a simple design in comparison to more complex conductor track systems, such as CBCPW arrangements, and the properties of the natural waves are decisively influenced by the geometry of the signal conductor10, in particular by the curvature and the width W, or the cross section of the signal conductor10, and by the thickness of the submount17or of the carrier circuit board of the signal conductor10. Without restriction to the examples discussed here, this relationship will be explained on the basis of several exemplary values. The limiting frequency of the higher-order waves is deeper the greater the width W of the signal conductor10is. If the line impedance is approximately half of the otherwise typical 50Ω, thus only 25Ω, with identical carrier circuit board, the 25Ω line is three times wider than a 50Ω line. The limiting frequency for higher-order waves is therefore a third lower in a 25Ω line than in a typical 50Ω line.

As shown inFIGS.19to28, the limiting frequency of the higher-order waves can be shifted toward high-frequency values by the embodiments presented in particular inFIGS.17a,17b,18, and29, for example over 80 GHz, so that the fundamental waves, thus the signal line is disturbed little or is even not disturbed at all up to frequency values of 80 GHz, preferably up to 90 GHz, preferably even at values above 100 GHz.

LIST OF REFERENCE SIGNS1conductor track arrangement2outer edge of the signal conductor 103inner edge of the signal conductor 104deflection area5deflection section of 26deflection section of 38inclination10signal conductor11ground conductor12corner13, 14leg16carrier17submount18gap in 1120socket21base of 2022feedthrough24platform26thermoelectric cooler27gap28electronic component part29bond wire30electronic component31cap32window33outer contour points34auxiliary circle35one end of the deflection area36other end of the deflection area38angle bisector40crescent-like area42field lineαdeflection angleHthickness of 1Wwidth of 10Wminminimal width of 10 at one end of 1D√{square root over (2)} × WRhradius of the auxiliary circleXinclination