Patent Description:
The present disclosure generally relates to wireless communications systems. More specifically, the present disclosure relates to a triple inductor transformer integrated in a diplexer/duplexer for multiband radio frequency integrated circuits.

Wireless communications systems are widely deployed to provide various types of communications content such as voice, video, data, and so on. These systems may be multiple-access systems capable of supporting simultaneous communications of multiple mobile devices with one or more base stations.

Reductions in both the size and cost of mobile devices and base stations may increase their marketability. Devices in wireless communications systems are increasingly configured to operate on multiple radio frequency (RF) bands utilizing multiple transmission technologies. One such way to reduce both the size and cost of mobile devices and base stations is the use of diplexers/duplexers. However, a device that operates on multiple radio frequency (RF) bands and that utilizes multiple transmission technologies has traditionally specified a separate switch for each radio frequency (RF) band and for each transmission technology. For example, a separate duplexer is specified for each radio frequency (RF) band and for each transmission technology. Benefits may be realized by an improved diplexer/duplexer for a radio frequency integrated circuit.

<CIT> disclosing an asymmetrical transformer output demultiplexing (ATODEM) circuit. The ATODEM circuit includes N input windings, wherein N is a natural number. Each of the N input windings have input terminals that couple to output terminals of N power amplifiers. The ATODEM further includes M output ports wherein M is a natural number, each of the M output ports having N series coupled windings coupled between a load terminal and a return terminal. The physical attributes of the N input windings, and the N series coupled windings of the M output ports are asymmetrical such that in an Nth operation mode an Nth PA first-load line impedance matches an output impedance of an Nth PA coupled to the input terminals.

<CIT> disclosing an apparatus for transmitting and receiving wireless communications. A balun is coupled to an antenna. The antenna transmits and receives radio frequency signals. The balun includes a first inductor including a first set of ports coupled to the antenna. The balun includes a second inductor with a second set of ports coupled to a power amplifier through a first circuit. The power amplifier transmits a first signal to the antenna. The balun also includes a third inductor with a third set of ports coupled to a low noise amplifier through a second circuit. The low noise amplifier receives a second signal from the antenna. The second set of ports is coupled to the first circuit and the third set of ports is coupled to the second circuit. Also, the first circuit is separate from the second circuit.

<CIT> disclosing a transformer including first loops and second loops. The first loops include a first set of input terminals. The first loops include at least three loops that are conductively coupled to each other in series by first crossovers. The second loops include a first set of output terminals. The second loops include at least three loops that are conductively coupled to each other in series by second crossovers. Each of the second conductive loops is inductively coupled to and nested within a respective one of the first conductive loops.

<CIT> disclosing an apparatus comprising a pair of inductors in an integrated circuit. A first inductor is arranged to occupy a first area of a substrate, the first inductor comprises a loop shape arranged to produce a first magnetic field. A second inductor is disposed at least partially within the first area and comprises a crossing shape that includes a multiplicity of loops, wherein the multiplicity of loops is arranged to produce a second and third magnetic field that cancel magnetic coupling between the first and second inductor.

<CIT> disclosing at least a pair of planar inductors for a wireless apparatus, for example transceivers used in a wireless device. A device may include a first planar inductor configured on a first area of a substrate. The first planar inductor includes a first loop configured to produce a first magnetic field in a first direction and a second loop configured to produce a second magnetic field in a second direction. The device further includes a second planar inductor configured on a second area of the substrate. The second planar inductor includes a third loop configured to produce a third magnetic field in a third direction. The third loop may be configured to surround the first loop and divide the second loop into an enclosed area and an external area.

A transformer has a first inductor that includes a first port. The transformer also has a second inductor magnetically coupled to the first inductor. The second inductor includes a second port. The second inductor includes a first portion configured to permit current flow in a clockwise direction and a second portion configured to permit current flow in a counter-clockwise direction. The transformer also has a third inductor magnetically coupled to the first inductor. The third inductor includes a third port. The counter-clockwise direction is opposite the clockwise direction to reduce magnetic coupling between the second inductor and the third inductor based on magnetic coupling cancellation.

A method of fabricating a transformer includes fabricating a first inductor that includes a first port. The method also includes fabricating a second inductor magnetically coupled to the first inductor. The second inductor includes a second port. The second inductor includes a first portion configured to permit current flow in a clockwise direction and a second portion configured to permit current flow in a counter-clockwise direction. The method further includes fabricating a third inductor magnetically coupled to the first inductor. The third inductor includes a third port. The counter-clockwise direction is opposite the clockwise direction to reduce magnetic coupling between the second inductor and the third inductor based on magnetic coupling cancellation.

A transformer includes a first means for storing energy in a magnetic field. The first energy storing means is accessible via a first port. The transformer also includes a second means for storing energy in a magnetic field. The second energy storing means is magnetically coupled to the first energy storing means. The second energy storing means is accessible via a second port. The second energy storing means includes a first portion configured to permit current flow in a clockwise direction and a second portion configured to permit current flow in a counter-clockwise direction. The transformer further includes a third means for storing energy in a magnetic field. The third energy storing means is magnetically coupled to the first energy storing means. The third energy storing means is accessible via a third port. The counter-clockwise direction is opposite the clockwise direction to reduce magnetic coupling between the second energy storing means and the third energy storing means based on magnetic coupling cancellation.

This has outlined, rather broadly, the features and technical advantages of the present disclosure in order that the detailed description that follows may be better understood. Additional features and advantages of the present disclosure will be described below. It should be appreciated by those skilled in the art that this present disclosure may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the teachings of the present disclosure as set forth in the appended claims. The novel features, which are believed to be characteristic of the present disclosure, both as to its organization and method of operation, together with further objects and advantages, will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

For a more complete understanding of the present disclosure, reference is now made to the following description taken in conjunction with the accompanying drawings.

As described herein, the use of the term "and/or" is intended to represent an "inclusive OR," and the use of the term "or" is intended to represent an "exclusive OR.

For wireless communications, a diplexer can help process signals carried in a carrier aggregation system. In carrier aggregation systems, signals are communicated with both high band and low band frequencies. In a chipset, the diplexer is usually inserted between an antenna and a tuner (or an RF switch) to ensure high performance. Usually, a diplexer design includes inductors and capacitors. Diplexers can attain high performance by using inductors and capacitors that have a high quality factor (or Q). Diplexers can also attain high performance by reducing the electromagnetic coupling between components, which may be achieved through a geometry and direction of the components. Thus, reducing the electromagnetic coupling between the various components in the diplexer, while decreasing the size of the diplexer and making the most economical use of resources, would be beneficial.

Aspects of the present disclosure are directed to reducing electromagnetic coupling between components of diplexers or duplexers. For example, aspects of the present disclosure are directed to a transformer with triple inductors that may be included in the diplexers or duplexers to reduce electromagnetic coupling. The transformer includes a first inductor, a second inductor, and a third inductor that respectively include a first port, a second port, and a third port. In one aspect, the second inductor overlaps the first inductor and/or the third inductor. The first port is a shared port and may correspond to an output or input of the transformer. The second port and the third port are ports to provide or receive independent signals to or from the first port. The second inductor is magnetically coupled to the first inductor. The third inductor is magnetically coupled to the first inductor. The first port, the second port, and the third port may be oriented at different angles with respect to each other. For example, the second port and the third port may be oriented at a same angle or may be orthogonal to each other.

The second inductor includes a first portion configured to permit current flow in a first direction (e.g., a clockwise direction) and a second portion configured to permit current flow in a second direction (e.g., a counter-clockwise direction) opposite the first direction. The second direction is opposite of the first direction to reduce magnetic coupling between the second inductor and the third inductor based on magnetic coupling cancellation. This configuration effectively causes magnetic flux between the third inductor and the second inductor to be cancelled to reduce magnetic coupling to the third inductor.

The second inductor may include at least one crossing portion of the inductor traces. For example, the second inductor includes an overlapped cross portion that couples the first portion to the second portion. For example, the second inductor may be shaped in accordance with a figure eight configuration. The overlapped cross portion may include a first conductive trace and a second conductive trace. The first conductive trace and the second conductive trace are in different conductive layers. For example, the first conductive trace is configured to permit the current to flow from the first portion to the second portion and the second conductive trace is configured to permit the current to return to the first portion from the second portion. Each of the first inductor, the second inductor, and/or the third inductor may include a center tap.

<FIG> is a schematic diagram of a radio frequency (RF) front-end (RFFE) module <NUM> employing passive devices including a triple inductor transformer integrated in a diplexer (e.g., a diplexer <NUM> of <FIG>)/duplexer (e.g., a duplexer <NUM> of <FIG>) for multiband radio frequency integrated circuits. The RF front-end module <NUM> includes power amplifiers <NUM>, the duplexer/filter <NUM>, and a radio frequency (RF) switch module <NUM>. The power amplifiers <NUM> amplify signal(s) to a certain power level for transmission. The duplexer/filters <NUM> filter the input/output signals according to a variety of different parameters, including frequency, insertion loss, rejection, or other like parameters. In addition, the RF switch module <NUM> may select certain portions of the input signals to pass on to the rest of the RF front-end module <NUM>.

The radio frequency (RF) front-end module <NUM> also includes tuner circuitry <NUM> (e.g., first tuner circuitry 112A and second tuner circuitry 112B), the diplexer <NUM>, a capacitor <NUM>, an inductor <NUM>, a ground terminal <NUM>, and an antenna <NUM>. The tuner circuitry <NUM> (e.g., the first tuner circuitry 112A and the second tuner circuitry 112B) includes components such as a tuner, a portable data entry terminal (PDET), and a house keeping analog-to-digital converter (HKADC). The tuner circuitry <NUM> may perform impedance tuning (e.g., a voltage standing wave ratio (VSWR) optimization) for the antenna <NUM>. The RF front-end module <NUM> also includes a passive combiner <NUM> coupled to a wireless transceiver (WTR) <NUM>. The passive combiner <NUM> combines the detected power from the first tuner circuitry 112A and the second tuner circuitry 112B. The wireless transceiver <NUM> processes the information from the passive combiner <NUM> and provides this information to a modem <NUM> (e.g., a mobile station modem (MSM)). The modem <NUM> provides a digital signal to an application processor (AP) <NUM>.

As shown in <FIG>, the diplexer <NUM> is between the tuner component of the tuner circuitry <NUM> and the capacitor <NUM>, the inductor <NUM>, and the antenna <NUM>. The diplexer <NUM> may be placed between the antenna <NUM> and the tuner circuitry <NUM> to provide high system performance from the RF front-end module <NUM> to a chipset including the wireless transceiver <NUM>, the modem <NUM>, and the application processor <NUM>. The diplexer <NUM> also performs frequency domain multiplexing on both high band frequencies and low band frequencies. After the diplexer <NUM> performs its frequency multiplexing functions on the input signals, the output of the diplexer <NUM> is fed to an optional LC (inductor/capacitor) network including the capacitor <NUM> and the inductor <NUM>. The LC network may provide extra impedance matching components for the antenna <NUM>, when desired. Then, a signal with the particular frequency is transmitted or received by the antenna <NUM>. Although a single capacitor and inductor are shown, multiple components are contemplated.

<FIG> is a schematic diagram of a wireless local area network (WLAN) (e.g., WiFi) module <NUM> including a first diplexer <NUM>-<NUM> and an RF front-end (RFFE) module <NUM> including a second diplexer <NUM>-<NUM> for a chipset <NUM>, including a triple inductor transformer integrated in a diplexer (e.g., the diplexer <NUM> of <FIG> or the first and second diplexers <NUM>-<NUM> and <NUM>-<NUM> of <FIG>)/duplexer (e.g., a duplexer <NUM> of <FIG> or a duplexer <NUM> of <FIG>) for multiband radio frequency integrated circuits. The WiFi module <NUM> includes the first diplexer <NUM>-<NUM> communicably coupling an antenna <NUM> to a wireless local area network module (e.g., WLAN module <NUM>). The RF front-end module <NUM> includes the second diplexer <NUM>-<NUM> communicably coupling an antenna <NUM> to the wireless transceiver (WTR) <NUM> through THE duplexer <NUM>. The wireless transceiver <NUM> and the WLAN module <NUM> of the WiFi module <NUM> are coupled to a modem (MSM, e.g., baseband modem) <NUM> that is powered by a power supply <NUM> through a power management integrated circuit (PMIC) <NUM>. The chipset <NUM> includes capacitors <NUM> and <NUM>, as well as an inductor(s) <NUM> to provide signal integrity.

The PMIC <NUM>, the modem <NUM>, the wireless transceiver <NUM>, and the WLAN module <NUM> each include capacitors (e.g., <NUM>, <NUM>, <NUM>, and <NUM>) and operate according to a clock <NUM>. In addition, the inductor <NUM> couples the modem <NUM> to the PMIC <NUM>.

<FIG> shows a block diagram of an exemplary design of wireless device <NUM> or user equipment. In this exemplary design, the wireless device <NUM> includes a transceiver <NUM> coupled to a primary antenna <NUM>, a transceiver <NUM> coupled to a secondary antenna <NUM>, and a data processor/controller <NUM>. The transceiver <NUM> includes multiple (K) receivers 330pa to 330pk and multiple (K) transmitters 350pa to 350pk to support multiple frequency bands, multiple radio technologies, carrier aggregation, etc. The transceiver <NUM> includes L receivers 330sa to 330sl and L transmitters 350sa to 350sl to support multiple frequency bands, multiple radio technologies, carrier aggregation, receive diversity, multiple-input multiple-output (MIMO) transmission from multiple transmit antennas to multiple receive antennas, etc..

In the exemplary design shown in <FIG>, each receiver <NUM> includes a low noise amplifier (LNA) <NUM> and receive circuits <NUM>. For data reception, the antenna <NUM> receives signals from base stations and/or other transmitter stations and provides a received radio frequency (RF) signal, which is routed through an antenna interface circuit <NUM> and presented as an input RF signal to a selected receiver <NUM>. An antenna interface circuit <NUM> may include switches, duplexers, diplexers, transmit filters, receive filters, matching circuits, etc. The description below assumes that the receiver 330pa is the selected receiver. Within the receiver 330pa, an LNA 340pa amplifies the input RF signal and provides an output RF signal. Receive circuits 342pa downconvert the output RF signal from RF to baseband, amplify and filter the downconverted signal, and provide an analog input signal to data processor <NUM>. Receive circuits 342pa may include mixers, filters, amplifiers, matching circuits, an oscillator, a local oscillator (LO) generator, a phase locked loop (PLL), etc. Each remaining receiver <NUM> in the transceivers <NUM> and <NUM> may operate in a similar manner as the receiver 330pa.

In the exemplary design shown in <FIG>, each transmitter <NUM> includes transmit circuits <NUM> and a power amplifier (PA) <NUM>. For data transmission, a data processor <NUM> processes (e.g., encodes and modulates) data to be transmitted and provides an analog output signal to a selected transmitter. The description below assumes that the transmitter 350pa is the selected transmitter. Within the transmitter 350pa, transmit circuits 352pa amplify, filter, and upconvert the analog output signal from baseband to RF and provide a modulated RF signal. The transmit circuits 352pa may include amplifiers, filters, mixers, matching circuits, an oscillator, an LO generator, a PLL, etc. A power amplifier (PA) 354pa receives and amplifies the modulated RF signal and provides a transmit RF signal having the proper output power level. The transmit RF signal is routed through the antenna interface circuit <NUM> and transmitted via the antenna <NUM>. Each remaining transmitter <NUM> in the transceivers <NUM> and <NUM> may operate in a similar manner as the transmitter 350pa.

<FIG> shows an exemplary design of a receiver <NUM> and transmitter <NUM>. The receiver <NUM> and a transmitter <NUM> may also include other circuits not shown in <FIG>, such as filters, matching circuits, etc. All or a portion of transceivers <NUM> and <NUM> may be implemented on one or more analog integrated circuits (ICs), RF ICs (RFICs), mixed-signal ICs, etc. For example, LNAs <NUM> and receive circuits <NUM> within transceivers <NUM> and <NUM> may be implemented on multiple ICs, as described below. The circuits in transceivers <NUM> and <NUM> may also be implemented in other manners.

The data processor/controller <NUM> may perform various functions for the wireless device <NUM>. For example, the data processor <NUM> may perform processing for data being received via the receivers <NUM> and data being transmitted via the transmitters <NUM>. The controller <NUM> may control the operation of the various circuits within the transceivers <NUM> and <NUM>. In some aspects, the transceivers <NUM> and <NUM> may also comprise a controller to control various circuits within the respective transceiver (e.g., LNAs <NUM>). A memory <NUM> may store program codes and data for the data processor/controller <NUM>. The data processor/controller <NUM> may be implemented on one or more application specific integrated circuits (ASICs) and/or other ICs.

<FIG> illustrates an example multi-path configuration <NUM> for concurrently receiving/transmitting in two different frequency bands. The configuration <NUM> shows a first frequency band path <NUM> (e.g., twenty-eight (<NUM>) gigahertz (GHz)) and a second frequency band path <NUM> (e.g., thirty-nine (<NUM>) GHz). Each of the first frequency band path <NUM> and the second frequency band path <NUM> is selectively coupled to an antenna (not shown) via a shared path <NUM>. For example, the first frequency band path <NUM> and the second frequency band path <NUM> are selectively coupled to the antenna by respective switches <NUM> and <NUM>.

The multi-path configuration <NUM> including the switches <NUM> and <NUM> is subject to drawbacks including increased parasitic resistance that results in additional loss and increased parasitic capacitance. Moreover, the switch implementation cannot combine two frequency bands to be transmitted simultaneously.

Aspects of the present disclosure are directed to a multi-path configuration that is based on a triple inductor transformer. For example, the triple inductor transformer may form a diplexer or be integrated in a diplexer for multiband radio frequency integrated circuits. The multi-path configuration (e.g., diplexer) combines two frequency band signals from two paths into one path or divides one path signal into two paths for two frequency bands. The examples are directed to a two-path configuration. However, it is to be appreciated that substantially limitless configurations (e.g., multiplexers) are possible.

<FIG> illustrates a triple inductor transformer <NUM>, according to aspects of the present disclosure. The triple inductor transformer <NUM> may be integrated in a diplexer/duplexer for multiband radio frequency integrated circuits. The triple inductor transformer <NUM> includes a first coil (or inductor) <NUM>, a second coil <NUM>, and a third coil <NUM>. The first coil <NUM> includes a first port, port1, which may be a differential port that includes a first sub-port <NUM> and a second sub-port <NUM>. The second coil <NUM> includes a second port, port2, which may be a differential port that includes a third sub-port <NUM> and a fourth sub-port <NUM>. The third coil <NUM> includes a third port, port3, which may be a differential port that includes a fifth sub-port <NUM> and a sixth sub-port <NUM>. Although not shown, all three of the ports (port1, port2, and port <NUM>) may be connected to capacitors, transistors, and/or resistors.

The triple inductor transformer <NUM> may be subject to magnetic coupling between the coils. The magnetic coupling may result in energy being transferred between the coils. The magnetic coupling coefficient between the first coil <NUM> and the second coil <NUM> is represented by k<NUM> and magnetic coupling coefficient between the first coil <NUM> and the third coil <NUM> is represented by k<NUM>. The magnetic coupling coefficients k<NUM> and k<NUM> are the desired magnetic coupling for the triple inductor transformer <NUM>.

The magnetic coupling coefficient between the second coil <NUM> and the third coil <NUM> is represented by k<NUM>. It is desirable to achieve a near zero magnetic coupling coefficient (k<NUM>) between the second port, port2, and the third port, port3. For example, the magnetic coupling coefficient k<NUM> should be less than <NUM>. A high performance diplexer with near zero magnetic coupling between the second port, port2, and the third port, port3, is achieved through a geometry and direction of the components, as illustrated in <FIG>. When the transformer is configured as a diplexer, each of the second port, port2, and the third port, port3, may be used for transmitting in one or more bands or for receiving in the one or more bands. In another aspect, the triple inductor transformer <NUM> may be a duplexer. For example, the second port, port2, may be used for transmitting in one or more bands and the third port, port3, may be used for receiving in the one or more bands.

The triple inductor transformer <NUM> according to aspects of the present disclosure removes insertion loss associated with a switch and achieves high isolation between the second port, port2, and the third port, port3. Moreover, the second port, port2, and the third port, port3, can send signals to the first port, port1, simultaneously.

<FIG> illustrates a schematic diagram of two inductors of a triple inductor transformer <NUM>, according to aspects of the present disclosure. For illustrative purposes, some of the labelling and numbering of the devices and features of <FIG> are similar to those of <FIG>. The two inductors may be the second coil <NUM> and the third coil <NUM>, shown in <FIG>. The second coil <NUM> may be shaped in accordance with a crossed configuration (e.g., a figure eight configuration). The third coil <NUM> may be configured to accommodate the crossed configuration of the second coil <NUM> in order to achieve a near zero magnetic coupling coefficient (k<NUM>) between the second port, port2, and the third port, port3, of the triple inductor transformer <NUM>. For example, the third coil <NUM> may designed in a substantially rectangular/square shape that partially surrounds the second coil <NUM>.

In one aspect, most of the conductive traces of each of the second coil <NUM> and the third coil <NUM> are in a same conductive layer (e.g., a first conductive layer). However, in regions where the second coil <NUM> and the third coil <NUM> overlap, the overlapped portions are in different layers (e.g., a second conductive layer and the first conductive layer). For example, port2 and port3 of the triple inductor transformer <NUM> are in different conductive layers. Similarly, in regions <NUM> and <NUM> where the second coil <NUM> and the third coil <NUM> overlap, the traces of the second coil <NUM> and the traces of the third coil <NUM> are in different layers. The traces in the different layers may be connected or coupled to other layers using vias.

When a radio frequency signal (e.g., current) is moved, a current is induced in the surrounding coils. For example, the current that enters at the second port, port2, flows through a first portion 516a and a second portion 516b of the second coil <NUM>, and an induced current is generated in the third coil <NUM>. The second coil <NUM> is designed in the figure eight configuration to cause current to flow in the first portion 516a in a clockwise direction while current flows in the second portion 516b in a counter-clockwise direction.

For example, the current in the clockwise direction is represented by the arrows a, b, c, d, e, and f. The current in the counter-clockwise direction is represented by the arrows g, h, i, j, and k. The current in the clockwise direction and the counter-clockwise direction traverse the second coil <NUM> through a cross region <NUM> through a first set of vias <NUM>, <NUM>, and a second set of vias <NUM> and <NUM>. For example, the current flows in the direction represented by the arrows a, b, and c in a first conductive layer then through the first set of vias <NUM>, <NUM> to a second conductive layer then back to the first conductive layer using the second set of vias <NUM> and <NUM>. The current then continues in the direction represented by the arrows g, h, i, j, k, d, e, and f.

The current in the clockwise direction generates a first induced current in a counter-clockwise direction represented by the arrows l and m. The current in the counter-clockwise direction generates a second induced current in a clockwise direction represented by the arrow n. The first induced current (represented by the arrows l and m) cancels out the second induced current (represented by the arrow n). In other words, the magnetic coupling between the second coil <NUM> and the third coil <NUM> is near or substantially zero. This follows because the first induced current in the direction represented by the arrows l and m cancels the second induced current in an opposing direction or counter-clockwise direction represented by the arrow n.

In one aspect of the disclosure, one or more corners of the first portion 516a and/or the second portion 516b of the second coil <NUM> are configured with different angles to increase efficiency. For example, the traces of the one or more corners may be connected at a desirable angle to reduce interference from nearby traces or devices. In one aspect, the traces of the one or more corners of the first portion 516a and/or the second portion 516b are configured at an angle less than ninety degrees (e.g., forty-five degrees). For example, a trace <NUM> corresponding to a corner of the second portion 516b is configured at an angle of forty-five degrees relative to a trace <NUM> of the second portion 516b.

Additionally, the cross/twist region <NUM> includes cross traces of the second coil <NUM> that are configured orthogonally. For example, a first cross trace <NUM> is orthogonal to a second cross trace <NUM>. The first cross trace <NUM> is in a different conductive layer than the second cross trace <NUM>.

<FIG> illustrates a schematic diagram of a triple inductor transformer <NUM>, according to aspects of the present disclosure. For illustrative purposes, some of the labelling and numbering of the devices and features of <FIG> are similar to those of <FIG> and <FIG>. <FIG>, however, includes the first coil (or inductor) <NUM> in combination with the second coil <NUM> and the third coil <NUM>, shown in <FIG>. The second coil <NUM> is shaped in accordance with a crossed configuration (e.g., a figure eight configuration). The first coil (or inductor) <NUM> and the third coil <NUM> may be configured to accommodate the crossed configuration of the second coil <NUM>. For example, the first coil <NUM> and the third coil <NUM> may be designed in a substantially rectangular/square shape that partially surrounds the second coil <NUM>. The first coil <NUM> and the third coil <NUM> may be designed to achieve the desirable magnetic coupling coefficient k<NUM> and k<NUM> for the triple inductor transformer <NUM>.

In this aspect of the present disclosure, the first coil <NUM> is designed in a substantially rectangular/square shape that partially surrounds the third coil <NUM>. In regions of the triple inductor transformer <NUM> where the first coil <NUM> overlaps the second coil <NUM> and the third coil <NUM>, the overlapped portions are in different conductive layers. For example, in regions <NUM> and <NUM> where the first coil <NUM> and the third coil <NUM> overlap, the traces of the first coil <NUM> and the traces of the third coil <NUM> are in different layers. Similarly, in region <NUM> where the first coil <NUM> and the second coil <NUM> overlap, the trace of the first coil <NUM> and the trace of the second coil <NUM> are in different layers. The traces in the different layers may be connected or coupled to other layers using vias. Each of the first coil <NUM>, the second coil <NUM>, and the third coil <NUM> include center tap routings. In the present disclosure, the first inductor <NUM> and third inductor <NUM> are designed with a one turn structure. In some applications, the inductors may be designed with multiple turns.

<FIG> illustrates a schematic diagram of a triple inductor transformer <NUM>, according to aspects of the present disclosure. For illustrative purposes, some of the labelling and numbering of the devices and features of <FIG> are similar to those of <FIG>, <FIG>, and <FIG>. However, a second coil <NUM> of <FIG> includes a first portion 816a and a second portion 816b that are shaped differently than the first portion 516a and the second portion 516b of the second coil <NUM> of <FIG> and <FIG>. In one aspect, one or more corners of the first portion 816a and/or the second portion 816b are orthogonal. For example, a trace <NUM> corresponding to a corner of the second portion 816b is configured at an angle of ninety degrees relative to a trace <NUM> of the second portion 816b. The first portion 816a and the second portion 816b can have a same or different shape or size.

<FIG> illustrates a schematic diagram of a triple inductor transformer <NUM>, according to aspects of the present disclosure. For illustrative purposes, some of the labelling and numbering of the devices and features of <FIG> are similar to those of <FIG>, <FIG>, <FIG>, and <FIG>. However, a second coil <NUM> of <FIG> includes a first portion 916a and a second portion 916b and a cross/twist region <NUM> that is shaped differently than the cross/twist region <NUM> of the second coil <NUM> of <FIG>, <FIG>, and <FIG>. In this aspect, the cross/twist region <NUM> includes cross traces of the second coil <NUM> that are configured diagonally. For example, a first cross trace <NUM> is diagonal relative to a second cross trace <NUM>.

<FIG> depicts a simplified flowchart of a method <NUM> of fabricating a transformer. At block <NUM>, a first inductor including a first port is fabricated. At block <NUM>, a second inductor magnetically coupled to the first inductor is fabricated. The second inductor includes a second port. The second inductor also includes a first portion configured to permit current flow in a clockwise direction and a second portion configured to permit current flow in a counter-clockwise direction. At block <NUM> a third inductor magnetically coupled to the first inductor and the second inductor is fabricated. The third inductor includes a third port. The counter-clockwise direction is opposite the clockwise direction to reduce magnetic coupling between the second inductor and the third inductor based on magnetic coupling cancellation.

According to one aspect of the present disclosure, a triple inductor transformer is described. The triple inductor transformer includes first, second and third means for storing energy in a magnetic field. The first energy storing means may, for example, be the first coil (or inductor) <NUM>. The second energy storing means may, for example, be the second coil <NUM>, the second coil <NUM>, and/or the second coil <NUM>. The third energy storing means may, for example, be the third coil <NUM>. In another aspect, the aforementioned means may be any module or any apparatus or material configured to perform the functions recited by the aforementioned means.

<FIG> is a block diagram showing an exemplary wireless communications system in which a configuration of the disclosure may be advantageously employed. For purposes of illustration, <FIG> shows three remote units <NUM>, <NUM>, and <NUM> and two base stations <NUM>. It will be recognized that wireless communications systems may have many more remote units and base stations. Remote units <NUM>, <NUM>, and <NUM> include IC devices 1125A, 1125B, and 1125C that include the disclosed triple inductor transformer. It will be recognized that other devices may also include the disclosed triple inductor transformer, such as the base stations, switching devices, and network equipment. <FIG> shows forward link signals <NUM> from the base station <NUM> to the remote units <NUM>, <NUM>, and <NUM> and reverse link signals <NUM> from the remote units <NUM>, <NUM>, and <NUM> to base station <NUM>.

In <FIG>, remote unit <NUM> is shown as a mobile telephone, remote unit <NUM> is shown as a portable computer, and remote unit <NUM> is shown as a fixed location remote unit in a wireless local loop system. For example, a remote unit may be a mobile phone, a hand-held personal communications systems (PCS) unit, a portable data unit such as a personal digital assistant (PDA), a GPS enabled device, a navigation device, a set top box, a music player, a video player, an entertainment unit, a fixed location data unit such as a meter reading equipment, or other communications device that stores or retrieves data or computer instructions, or combinations thereof. Although <FIG> illustrates remote units according to the aspects of the disclosure, the disclosure is not limited to these exemplary illustrated units. Aspects of the disclosure may be suitably employed in many devices, which include the triple inductor transformer.

<FIG> is a block diagram illustrating a design workstation used for circuit, layout, and logic design of a triple inductor transformer. A design workstation <NUM> includes a hard disk <NUM> containing operating system software, support files, and design software such as Cadence or OrCAD. The design workstation <NUM> also includes a display <NUM> to facilitate design of a circuit <NUM> or the triple inductor transformer. A storage medium <NUM> is provided for tangibly storing the design of the circuit <NUM> or the triple inductor transformer. The design of the circuit <NUM> or the triple inductor transformer may be stored on the storage medium <NUM> in a file format such as GDSII or GERBER. The storage medium <NUM> may be a CD-ROM, DVD, hard disk, flash memory, or other appropriate device. Furthermore, the design workstation <NUM> includes a drive apparatus <NUM> for accepting input from or writing output to the storage medium <NUM>.

Data recorded on the storage medium <NUM> may specify logic circuit configurations, pattern data for photolithography masks, or mask pattern data for serial write tools such as electron beam lithography. The data may further include logic verification data such as timing diagrams or net circuits associated with logic simulations. Providing data on the storage medium <NUM> facilitates the design of the circuit <NUM> or the triple inductor transformer.

For a firmware and/or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. A machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory and executed by a processor unit. Memory may be implemented within the processor unit or external to the processor unit. As used herein, the term "memory" refers to types of long term, short term, volatile, nonvolatile, or other memory and is not to be limited to a particular type of memory or number of memories, or type of media upon which memory is stored.

If implemented in firmware and/or software, the functions may be stored as one or more instructions or code on a computer-readable medium. Examples include computer-readable media encoded with a data structure and computer-readable media encoded with a computer program. Computer-readable media includes physical computer storage media. A storage medium may be an available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer; disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

In addition to storage on computer-readable medium, instructions and/or data may be provided as signals on transmission media included in a communications apparatus. For example, a communications apparatus may include a transceiver having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the claims.

A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Claim 1:
A transformer (<NUM>), comprising:
a first inductor (<NUM>) configured as a first coil (<NUM>) comprising conductive traces and including a first port;
a second inductor (<NUM>) configured as a second coil (<NUM>) comprising conductive traces and magnetically coupled to the first inductor (<NUM>), the second inductor (<NUM>) including a second port, the second inductor (<NUM>) comprising a first portion (516a) configured to permit current flow in a clockwise direction and a second portion (516b) configured to permit current flow in a counter-clockwise direction, wherein the second coil is shaped in accordance with a figure eight configuration comprising an overlapped cross portion (<NUM>) that couples the first portion (516a) and the second portion (516b); and
a third inductor (<NUM>) configured as a third coil (<NUM>) comprising conductive traces and magnetically coupled to the first inductor (<NUM>), the third inductor (<NUM>) including a third port, wherein each of the first coil (<NUM>) and the third coil (<NUM>) are designed in a substantially rectangular shape that partially surrounds the second coil (<NUM>), wherein the third coil (<NUM>) is configured to accommodate the second coil (<NUM>) with its cross portion (<NUM>) such that the counter-clockwise direction is opposite the clockwise direction to reduce magnetic coupling between the second inductor (<NUM>) and the third inductor (<NUM>) based on magnetic coupling cancellation.