CN106373739A - Petal-shaped concave-convex twenty-quadrilateral transformer - Google Patents

Abstract

The invention discloses a petal-shaped concave-convex twenty-quadrilateral transformer, which comprises a surrounding body formed by mutually surrounding primary winding and secondary winding at intervals, wherein the surrounding body is a concave-convex twenty-quadrilateral and is provided with eight inward-concave inner corners and sixteen outward-convex outer corners, and the outer corners and the inner corners are both 2: 1 adjacent setting, simple structure is novel, and quality factor is high, and self-resonant frequency is high, and elementary wire winding and secondary wire winding inductance value are high, only need less chip area, can provide signal and impedance conversion function in the circuit that the on-chip radio frequency meets transmitting system, can realize under multiple technology, reduce the use quantity of inductance, reduce chip area, have reached high device performance and low chip area's purpose.

Description

A kind of concavo-convex 20 tetragon transformators of petal-shaped

Technical field

The present invention relates to a kind of transformator of radio communication IC chip, belong to technical field of integrated circuits.

Background technology

At present, transformator is applied widely in radio communication integrated circuit SOC(system on a chip).In RF IC Emitting portion and receiving portion are required for using transformator, and transformator is real in low-noise amplifier, frequency mixer, power amplifier Existing signal coupling and impedance conversion, simultaneously also because of the primary and secondary mutual inductance effect of coiled wire-wound coil, improve its quality factor and inductance Value.However, when making in integrated circuits and realizing the efficient performance of transformator, its chip area need to be reduced, reduces transformator damage Consumption is it is ensured that signal effectively transmits.Accordingly, it would be desirable to improve structure and the shape of transformator, improve its characteristic and function.

The patent documentation of Publication No. " us20080042792a1 " discloses the change of a kind of entitled " on-chip transformer balun " Depressor structure, its technical scheme adopting as shown in figure 1, to be designed using the top-level metallic of square structure, wherein primary coiling (numbering 12) adopts series system by outer ring to inner ring, then by inner ring to outer ring；Secondary rolling thread (numbering 13) is using side in parallel Formula, thus meeting the high coefficient of coup, reduces the resistance of secondary rolling thread, and structure is simpler, is easy to extensively apply.But, phase Ever-increasing octagon, non-entirely convex ten hexagons (the patent documentation public affairs as Publication No. " cn102184910b " for side number " the non-entirely convex ten hexagon transformer Baluns " opened) and concavo-convex 20 tetragons of petal-shaped etc., its quality factor q value is still relatively Relatively low.

Content of the invention

In order to overcome the deficiencies in the prior art, the present invention provides a kind of high-quality-factor, high self resonant frequency, and height is first, secondary Level coil inductance, the concavo-convex 20 tetragon transformators of the little petal-shaped of chip occupying area.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of concavo-convex 20 tetragon transformators of petal-shaped, including by primary coiling and secondary rolling thread spaced around shape The surrounding body becoming, described surrounding body is 20 concavo-convex tetragons, has eight interior angles concaving and cambered outwards 16 Exterior angle, is 2:1 and is disposed adjacent between exterior angle and interior angle.

The interior angle of described surrounding body and exterior angle are 135 degree.

The intersecting angle at the coiling of described primary and the overlapping position of secondary rolling thread is 90 degree.

The coiling of described primary and secondary rolling thread are same metal material.

The invention has the beneficial effects as follows: the present invention increased the side number of transformator on the basis of considering technological design rule And angle, the interior angle of surrounding body and exterior angle are 135 degree so that the length of primary coiling and secondary rolling thread is in the certain feelings of area Longer than the primary coiling of traditional winding mode transformator and the length of secondary coiling under condition, lead to primary coiling and secondary rolling thread The inductance value of coil increase, solve and need because improving the inductance value of primary coiling and secondary rolling thread to increase number of turns Problem, thus saving chip area, meanwhile, the increasing and be favorably improved quality factor q value and self-resonant frequency of side number.Just The intersecting angle at level coiling and the overlapping position of secondary rolling thread is 90 degree, and the area relative area of overlapping part is less, corresponding Parasitic capacitance value between coiled wire-wound coil also reduces therewith, thus also improves its self-resonant frequency, and structure is simply novel, quality because Son is high, and self-resonant frequency is high, primary coiling and secondary rolling thread inductance value high it is only necessary to less chip area, can be on piece Radio frequency connects in the circuit of emission system and provides signal and impedance transformation function, can realize under kinds of processes, minimizing inductance Usage quantity, reduces chip area, has reached high device performance and the purpose of low chip area.

Brief description

The present invention is further described with reference to the accompanying drawings and examples.

Fig. 1 is on-chip transformer structural representation of the prior art；

Fig. 2 is the structural representation of the present invention；

Fig. 3 is substrate and the metal-layer structure schematic diagram of the present invention；

Fig. 4 is the self-resonant frequency performance plot of the present invention and other three kinds of transformators；

Fig. 5 is the quality factor performance plot of the present invention and other three kinds of transformators；

Fig. 6 is the Insertion Loss performance plot in the present invention and other three kinds of transformator working bands.

Specific embodiment

With reference to Fig. 2, a kind of concavo-convex 20 tetragon transformators of petal-shaped, including mutual by primary coiling and secondary rolling thread Around the surrounding body of the flat thin lamellar being formed, wherein, port 1, port 2 are the port of primary coiling to spacer ring, and port 3, port 4 are The port of secondary rolling thread.Described surrounding body is 20 concavo-convex tetragons, has eight interior angles and cambered outwards ten concaving Six exterior angles, are 2:1 and are disposed adjacent between exterior angle and interior angle, the interior angle of described surrounding body and exterior angle are 135 degree, due to electricity The size of sense is relevant with the length of coiling, and increases with the increase of length, and the present invention makes primary coiling using 135 degree of angles Primary coiling and the secondary coiling than traditional winding mode transformator in the case that area is certain with the length of secondary rolling thread Length is long, leads to the inductance value of the coil of primary coiling and secondary rolling thread to increase, solve because improve primary coiling and secondary around The inductance value of line and need to increase the problem of number of turns, thus saving chip area, meanwhile, the increasing and contribute to of side number Improve quality factor q value and self-resonant frequency.

The intersecting angle at the coiling of described primary and the overlapping position of secondary rolling thread is 90 degree, the area relative area of overlapping part Less, the parasitic capacitance value between corresponding coiled wire-wound coil also reduces therewith, thus also improves its self-resonant frequency.

Described primary and secondary coiling be same metal material, mainly based on the top-level metallic of current process, this be by Thicker in the relatively other layer metal thickness of top-level metallic, and electrical conductivity is also higher, its resistance under straight, exchange status is also relatively Less, with substrate distance farther out, be conducive to improving the quality factor q value of transformator and reduce insertion loss.Primary coiling and time Between level coiling, metal cross section, from time high level metal, somewhat reduces with respect to the thickness of top-level metallic, this layout side Formula is conducive to improving the characterisitic parameter required by transformator, reduces the part being unfavorable for its performance, in particular by top-level metallic Wiring can improve the distance between metal wound wire and substrate, reduce transformator to substrate effect, reduce parasitic capacitance.

The substrate of the present invention and metal-layer structure as shown in figure 3, be followed successively by from top to bottom top-level metallic b, sublevel metal c, Third layer metal d, the 4th layer of metal e, layer 5 metal g, layer 6 metal g and substrate layer h, wherein, top-level metallic b thickness is Thickness, next to that sublevel metal c, after third layer metal d starts, the metal thickness of each layer is equal.According to the electric current under high frequency condition Flow through in the conductor and Kelvin effect occurs, thus select the thicker top-level metallic of thickness to be more beneficial for its thing making transformator Electrology characteristic in reason.Through hole a1, through hole a2 and through hole a3 are respectively between top-level metallic b and secondary high level metal c, secondary high-rise gold Belong to the connection between c and third layer metal d and between third layer metal d and the 4th layer of metal e, thus realizing the metal of coiling Intersection avoids the connection of short-circuiting percentage, the physics realization effect having reached, the thickness of substrate layer h and doping content will affect transformation The performance of device, in order to reach the effect selection thickness substrate of design of transformer, the substrate doping of low concentration.

The transformer parameter of the present invention is calculated as follows:

If the inductance of the primary coil of transformator is l₁₁, secondary inductance is l₂₂, then:

l_ii=imag (z_ii)/(2*π*f)

The quality factor of primary coil and secondary coil is respectively q₁₁, q₂₂, then:

$q_{ii}=\frac{imag(1/y_{ii})}{real(1/y_{ii})}$

Wherein, i=1,2, z, y be Wei the impedance of coil port and admittance.

The calculation expression of the self-resonant frequency of monolateral coil is as follows:

$f=\frac{1}{2\mathrm{\π}\sqrt{(1+k){\mathrm{lc}}_{ox}}}{(1-\frac{r^2{c}_{ox}}{(1+k)l})}^{\frac{1}{2}}$

Wherein, k is the coefficient of coup, r and l is monolateral coil resistance and inductance, c_oxIt is the oxidation layer capacitance and substrate between.

The expression formula of coil degree of coupling is:

$k=\sqrt{\frac{imag\left(z_{12}\right)\×imag\left(z_{21}\right)}{imag\left(z_{11}\right)\×imag\left(z_{22}\right)}}$

Wherein, z₁₁、z₂₂For the input of transformer coil, output port impedance；z₁₂、z₂₁For the input of transformer coil, defeated Mutual impedance between exit port, related other parameters can calculate according to related documents and materials.

Transformer performance characteristic of the present invention as shown in Figs. 4-6 (ads simulation software, the sectional drawing in version number 2009), first In the case of level coiling and secondary rolling thread inductance value and turn ratio identical, from fig. 4, it can be seen that the transformator self-resonance frequency of the present invention Rate highest, reaches 13.68ghz, and self-resonant frequency height is conducive to application in wider frequency range for the transformator.Can from Fig. 5 Go out, the transformator quality factor highest of the present invention, reach 21.11, primary coiling is consistent with the performance of secondary rolling thread.From figure 6 as can be seen that three kinds of transformators of transformator and other of the present invention are almost identical in the performance of Insertion Loss aspect of performance, and change is not It is obvious that showing that this several transformator can meet design requirement in performance indications.

The transformer device structure of the present invention is simply novel, and quality factor is high, self-resonant frequency height, primary coiling and secondary rolling thread It is only necessary to less chip area, can connect in radio frequency on piece provides signal and impedance to inductance value height in the circuit of emission system Translation function, can realize under kinds of processes, reduce the usage quantity of inductance, reduce chip area, reached high device Can be with the purpose of low chip area.

It is emphasized that above embodiment can not limit the protection domain of the invention, without departing from the present invention Create general idea in the case of, the personnel of professional skill field can carry out various change and remodeling, as long as these change and Remodeling, without departing from the objective of the invention, all still falls within the scope of the invention covers.

Claims (4)

1. the concavo-convex 20 tetragon transformators of a kind of petal-shaped, including by primary coiling and secondary rolling thread spaced around being formed Surrounding body it is characterised in that: described surrounding body is 20 concavo-convex tetragons, has eight interior angles concaving and convex 16 exterior angles, be 2:1 between exterior angle and interior angle and be disposed adjacent.

2. the concavo-convex 20 tetragon transformators of petal-shaped according to claim 1 it is characterised in that: described surrounding body interior Angle and exterior angle are 135 degree.

3. the concavo-convex 20 tetragon transformators of petal-shaped according to claim 1 and 2 it is characterised in that: described primary around The intersecting angle at line and the overlapping position of secondary rolling thread is 90 degree.

4. the concavo-convex 20 tetragon transformators of the petal-shaped according to claim 1,2 or 3 it is characterised in that: described primary Coiling and secondary rolling thread are same metal material.