8-shaped inductor

• US 8,183,971 B2
• Filed: 04/02/2009
• Issued: 05/22/2012
• Est. Priority Date: 04/10/2008
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Le Guillou, Yann, Fahs, Bassem
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US12/936,982
• Publication Number:
  US 20110032067A1
• Time in Patent Office: 1,146 Days
• Field of Search: 336/200, 336225-226
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 2017/0073 with a special conductive pattern, e.g. flat spiral
• CPC Class Codes: H01F 2017/0086 on semiconductor substrate inductors for integrated circuits H01L28/10
• CPC Class Codes: H01F 27/346 Preventing or reducing leakage fields using magnetic shields H01F27/36; using auxiliary windings H01F27/38
• CPC Class Codes: H03B 5/1841 the frequency-determining element being a strip line resonator H03B5/1805, H03B5/1817, H03B5/1864 and H03B5/1882 take precedence

Abstract

In a first aspect, the invention provides to a device comprising a substrate and an electrical conductor arranged between two terminals (A, B) and shaped for forming an inductor comprising at least two loops (1, 2) and arranged such that, at least locally, the far field is reduced. This arrangement results in an inductor which radiates a smaller magnetic field, also referred to as reduced EMI, which results in less noise generated in other inductive parts of an electronic circuit or system. The invention further provides in an advantageous embodiment proper balancing of the parasitic resistance and capacitance. By doing so the physical mid-point of 8-shaped inductors becomes the electrical mid-point (MP) which is beneficial when the inductor is used in a circuit. In a second aspect the invention provides an electronic system comprising the device according to the invention, wherein the electronic system comprises an LC-based voltage-controlled oscillator comprising the inductor, the electronic system being one of a group comprising: a multi-channel TV-receiver, a full-duplex transceiver, and a co-banding system. All these systems benefit from the symmetrical properties of the inductor. The better far-field compensation leads to a smaller VCO pulling effect which leads to a better performance of the system.

Claims

1. A device comprising:

a substrate;

a first terminal and a second terminal;

an electrical conductor arranged on the substrate between the first terminal and the second terminal to obtain an inductor and being shaped for forming a first loop and a second loop, wherein at least a first crossing of the electrical conductor with itself is present between the first loop and the second loop, the first loop and the second loop defining a first enclosed area and a second enclosed area, respectively, and wherein the first loop and the second loop are arranged for generating magnetic fields having substantially equal strength and opposite directions to obtain a reduction of a far field generated by the inductor, wherein the electrical conductor is provided with a second crossing with itself between the terminals and the second loop for further defining the boundary of the second enclosed area.

2. Electronic system comprising the device of claim 1, the electronic system being one of a group comprising:

a multi-channel TV-receiver, a full-duplex transceiver, and a co-banding system.

3. The device as claimed in claim 1, wherein the electrical conductor is further shaped for forming a third loop and a fourth loop, wherein a least a third crossing of the electrical conductor with itself is present between the third loop and the fourth loop, the third loop and the fourth loop defining a third enclosed area and a fourth enclosed area, respectively, and wherein the third loop and the fourth loop are arranged for generating magnetic fields having substantially equal strength and opposite directions to obtain, at least locally, a reduction of a far field generated by the inductor, wherein the conductor is further provided with a fourth crossing with itself connecting the first loop with the fourth loop thereby further defining the boundaries of the first enclosed area and the fourth enclosed area.

4. The device as claimed in claim 3, wherein all loops are arranged to obtain non-overlapping areas, the first loop being connected between the fourth loop and the second loop, the fourth loop being connected between the first loop and the third loop to obtain an 8-shaped structure in series with an 8-shaped structure.

5. The device as claimed in claim 4, wherein the third loop is arranged within the first loop and the fourth loop is arranged within the second loop thereby forming a fifth crossing for further defining the fourth enclosed area, and forming a sixth crossing for further defining the first and second enclosed area, to obtain an 8-within-8 shaped structure.

6. The device according to claim 1 comprising at least a first interconnect layer formed on the substrate and a second interconnect layer arranged to cooperate with the first interconnect layer, wherein the electrical conductor comprises a main part laid out in the second interconnect layer, and wherein the first crossing and second crossing each comprise a further part laid out in the first interconnect layer, the further part crossing the main part, the further part being connected to the main part by means of contacts or vias to obtain the first and second crossing of the electrical conductor wherein crossing conductor parts are electrically insulated with respect to each other by a dielectric layer in between the main part and the further part.

7. The device of claim 6, wherein the first crossing and the second crossing are constructed such that one is an pass-over structure and the other is an pass-under structure considered on a path along the conductor between the first terminal and a mid-point, the mid-point being defined on the conductor at a distance matching half the length of the conductor between the terminals.

8. The device of claim 6, wherein the crossings are constructed such that the number of pass-over structures equals the number of pass-under structures considered on a path along the conductor between the first terminal and a mid-point, the mid-point being defined on the conductor at a distance matching half the length of the conductor between the terminals.

9. The device according to claim 1, wherein the inductor is part of an electronic circuit selected from a group comprising:

an RF filter, a LC-based voltage-controlled oscillator, an LC-based differential amplifier, a mixer, a Tx amplifier, and a load driver.

10. The device of claim 1, wherein the substrate is a semiconductor substrate to obtain a semiconductor device.