The present disclosure relates generally to wireless communication and, more particularly, to transmission of wireless communications in multiple frequency bands.
Wireless communications systems are used in a variety of telecommunications systems, television, radio and other media systems, data communication networks, and other systems to convey information between remote points using wireless transmitters and wireless receivers. A transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications. Transmitters often include signal amplifiers which receive a radio-frequency or other signal, amplify the signal by a predetermined gain, and communicate the amplified signal. On the other hand, a receiver is an electronic device which, also usually with the aid of an antenna, receives and processes a wireless electromagnetic signal. In certain instances, a transmitter and receiver may be combined into a single device called a transceiver.
In many modern wireless communication systems, it may desirable to transmit wireless signals at multiple frequencies or “bands.” Traditionally, transmitters include multiple transmit chains (essentially, multiple transmitters) in order to support transmission at multiple frequencies. Traditional transmitters often used this approach as separate transformers were required for each frequency. Transformers used in transmitters are often integrated on a semiconductor chip (e.g., in a CMOS process), and thus may be referred to as integrated transformers.
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils—via a phenomenon known as mutual induction. With mutual induction, a varying current in a primary winding of a transformer creates a varying magnetic flux in a core of the transformer about which the windings are wound, and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF) or voltage in the secondary winding. If a load is connected to the secondary, an electric current will flow in the secondary winding and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding is in proportion to the primary voltage, and is given by the ratio of the number of turns in the secondary to the number of turns in the primary.
In accordance with embodiments of the present disclosure, multi-tap integrated transformer may include a primary winding and a secondary winding. The a primary winding may have a plurality of primary winding taps coupled thereto, the plurality of primary winding taps including a pair of primary winding taps configured to receive a differential input signal. The secondary winding may have a plurality of secondary winding taps coupled thereto, the plurality of secondary winding taps including a first pair of secondary winding taps configured to output a first output signal and a second pair of secondary winding taps configured to output a second output signal. The first output signal may be based on the differential input signal and a first mutual inductance between a portion of the primary winding between the pair of primary winding taps and a first portion of the secondary winding between the first pair of secondary winding taps. The second output signal may be based on the differential input signal and a second mutual inductance between the portion of the primary winding between the pair of primary winding taps and a second portion of the secondary winding between the second pair of secondary winding taps, the second mutual inductance different than the first mutual inductance.
In accordance with the same or alternative embodiments of the present disclosure, a multi-tap integrated transformer may include a primary winding and a secondary winding. The primary winding may have a plurality of primary winding taps coupled thereto, the plurality of primary winding taps including a first pair of secondary winding taps configured to receive a first differential input signal and a second pair of primary winding taps configured to receive a first differential input signal. The secondary winding may have a plurality of secondary winding taps coupled thereto, the plurality of secondary winding taps including a first pair of secondary winding taps configured to output a first output signal and a second pair of secondary winding taps configured to output a second output signal. The first output signal may be based on the first differential input signal and a first mutual inductance between a first portion of the primary winding between the first pair of primary winding taps and a first portion of the secondary winding between the first pair of secondary winding taps. The second output signal may be based on the second differential input signal and a second mutual inductance between a second portion of the primary winding between the second pair of primary winding taps and a second portion of the secondary winding between the second pair of secondary winding taps, the second mutual inductance different than the first mutual inductance.
In accordance with these and other embodiments of the present disclosure, a multi-tap integrated transformer may include a winding having a plurality of taps coupled thereto. The plurality of taps may include a pair of primary taps, a first pair of secondary taps, and a second pair of secondary taps. The pair of primary taps may be configured to receive a differential input signal. The first pair of secondary taps may be configured to output a first output signal. The second pair of secondary taps may be configured to output a second output signal.
Technical advantages of one or more embodiments of the present disclosure may include a multi-band transmitter with a reduced number of integrated transformers, as compared with traditional transmitters.
It will be understood that the various embodiments of the present disclosure may include some, all, or none of the enumerated technical advantages. In addition, other technical advantages of the present disclosure may be readily apparent to one skilled in the art from the figures, description and claims included herein.
For a more complete understanding of the present disclosure and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
A terminal 110 may or may not be capable of receiving signals from satellites 130. Satellites 130 may belong to a satellite positioning system such as the well-known Global Positioning System (GPS). Each GPS satellite may transmit a GPS signal encoded with information that allows GPS receivers on earth to measure the time of arrival of the GPS signal. Measurements for a sufficient number of GPS satellites may be used to accurately estimate a three-dimensional position of a GPS receiver. A terminal 110 may also be capable of receiving signals from other types of transmitting sources such as a Bluetooth transmitter, a Wireless Fidelity (Wi-Fi) transmitter, a wireless local area network (WLAN) transmitter, an IEEE 802.11 transmitter, and any other suitable transmitter.
In
System 100 may be a Code Division Multiple Access (CDMA) system, a Time Division Multiple Access (TDMA) system, or some other wireless communication system. A CDMA system may implement one or more CDMA standards such as IS-95, IS-2000 (also commonly known as “1x”), IS-856 (also commonly known as “1xEV-DO”), Wideband-CDMA (W-CDMA), and so on. A TDMA system may implement one or more TDMA standards such as Global System for Mobile Communications (GSM). The W-CDMA standard is defined by a consortium known as 3GPP, and the IS-2000 and IS-856 standards are defined by a consortium known as 3GPP2.
As depicted in
Transmit path 201 may include a digital-to-analog converter (DAC) 204. DAC 204 may be configured to receive a digital signal from digital circuitry 202 and convert such digital signal into an analog signal. Such analog signal may then be passed to one or more other components of transmit path 201, including upconverter 208.
Upconverter 208 may be configured to frequency upconvert an analog signal received from DAC 204 to a wireless communication signal at a radio frequency based on an oscillator signal provided by oscillator 210. Oscillator 210 may be any suitable device, system, or apparatus configured to produce an analog waveform of a particular frequency for modulation or upconversion of an analog signal to a wireless communication signal, or for demodulation or downconversion of a wireless communication signal to an analog signal. In some embodiments, oscillator 210 may be a digitally-controlled crystal oscillator.
Transmit path 201 may include a variable-gain amplifier (VGA) 214 to amplify an upconverted signal for transmission, and a bandpass filter 216 configured to receive an amplified signal VGA 214 and pass signal components in the band of interest and remove out-of-band noise and undesired signals. The bandpass filtered signal may be received by power amplifier 220 where it is amplified for transmission via antenna 218. Antenna 218 may receive the amplified and transmit such signal (e.g., to one or more of a terminal 110, a base station 120, and/or a satellite 130).
As mentioned previously, certain components of transmit path 201 may include transformers. For example, upconverter 208, variable gain amplifier 214, power amplifier 220, and/or another component of transmit path 201 may include transformers, including without limitation, the multi-tap transformers discussed in detail with respect to
Receive path 221 may include a bandpass filter 236 configured to receive a wireless communication signal (e.g., from a terminal 110, a base station 120, and/or a satellite 130) via antenna 218. Bandpass filter 236 may pass signal components in the band of interest and remove out-of-band noise and undesired signals. In addition, receive path 221 may include a low-noise amplifier (LNA) 224 to amplify a signal received from bandpass filter 236.
Receive path 221 may also include a downconverter 228. Downconverter 228 may be configured to frequency downconvert a wireless communication signal received via antenna 218 and amplified by LNA 234 by an oscillator signal provided by oscillator 210 (e.g., downconvert to a baseband signal). Receive path 221 may further include a filter 238, which may be configured to filter a downconverted wireless communication signal in order to pass the signal components within a radio-frequency channel of interest and/or to remove noise and undesired signals that may be generated by the downconversion process. In addition, receive path 221 may include an analog-to-digital converter (ADC) 224 configured to receive an analog signal from filter 238 and convert such analog signal into a digital signal. Such digital signal may then be passed to digital circuitry 202 for processing.
The embodiment of
In operation of transformer 302, the mutual inductance between the portion of primary winding 304 between taps 306 and the portion of secondary winding 308 between taps 310a may be different than the mutual inductance between the portion of primary winding 304 between taps 306 and the portion of secondary winding 308 between taps 310b. Accordingly, a differential input signal applied to taps 306 may induce a first differential output signal between taps 310a different than that of a second differential output signal between taps 310b. In addition, the inductance of secondary winding 308 between taps 310a and/or a load coupled to taps 310a may tune the first differential output signal for operation at a first frequency and the inductance of secondary winding 308 between taps 310b and/or a load coupled to taps 310b may tune the second differential output signal for operation at a second frequency different from the first frequency. Thus, multi-tap integrated transformer 302 permits signal transformation for multiple frequency bands (e.g., Band 1 for taps 310a and Band 2 for taps 310b as indicated in
The embodiment of
In operation of transformer 322, the mutual inductance between the portion of primary winding 324 between taps 326 and the portion of secondary winding 328 between taps 330a may be different than the mutual inductance between the portion of primary winding 324 between taps 326 and the portion of secondary winding 328 between taps 330b. Accordingly, a differential input signal applied to taps 326 may induce a first differential output signal between taps 330a different than that of a second differential output signal between taps 330b. In addition, the inductance of secondary winding 328 between taps 330a and/or a load coupled to taps 330a may tune the first differential output signal for operation at a first frequency and the inductance of secondary winding 328 between taps 330b and/or a load coupled to taps 330b may tune the second differential output signal for operation at a second frequency different from the first frequency. Thus, multi-tap integrated transformer 322 permits signal transformation for multiple frequency bands (e.g., Band 1 for taps 330a and Band 2 for taps 330b as indicated in
The embodiment of
In operation of transformer 342, a first mutual inductance may exist between the portion of primary winding 344 between taps 346a and the portion of secondary winding 348 between taps 350a and 350c. A second mutual inductance may exist between the portion of primary winding 344 between taps 346b and the portion of secondary winding 348 between taps 350b and 350c. Accordingly, a first differential input signal applied to taps 346a may induce a first single-ended output signal between taps 350a and 350c, and a second differential input signal applied to taps 346b may induce a second single-ended output signal between taps 350b and 350c. In addition, the inductance of secondary winding 348 between taps 350a and 350c and/or a load coupled to tap 350a may tune the first single-ended output signal for operation at a first frequency and the inductance of secondary winding 348 between taps 350b and 350c and/or a load coupled to tap 350b may tune the second single-ended output signal for operation at a second frequency different from the first frequency. Thus, multi-tap integrated transformer 342 permits signal transformation for multiple frequency bands (e.g., Band 1 for tap 350a and Band 2 for tap 350b as indicated in
The embodiment of
In operation of transformer 362, a first mutual inductance may exist between the portion of primary winding 364 between taps 366a and the portion of secondary winding 368 between taps 370a. A second mutual inductance may exist between the portion of primary winding 364 between taps 366b and the portion of secondary winding 368 between taps 370b. Accordingly, a first differential input signal applied to taps 366a may induce a first differential output signal between taps 370a, and a second differential input signal applied to taps 366b may induce a second differential output signal between taps 370b. In addition, the inductance of secondary winding 368 between taps 370a and/or a load coupled to taps 370a may tune the first differential output signal for operation at a first frequency and the inductance of secondary winding 368 between taps 370b and/or a load coupled to tap 370b may tune the second differential output signal for operation at a second frequency different from the first frequency. Thus, multi-tap integrated transformer 362 permits signal transformation for multiple frequency bands (e.g., Band 1 for tap 370a and Band 2 for tap 370b as indicated in
The embodiment of
In operation of transformer 382, a differential input signal applied to taps 386 may induce a first differential output signal between taps 390a different than that of a second differential output signal between taps 390b. In addition, the inductance of secondary portion 388 between taps 390a and/or a load coupled to taps 390a may tune the first differential output signal for operation at a first frequency and the inductance of secondary portion 388 between taps 390b and/or a load coupled to taps 390b may tune the second differential output signal for operation at a second frequency different from the first frequency. Thus, multi-tap integrated transformer 382 permits signal transformation for multiple frequency bands (e.g., Band 1 for taps 390a and Band 2 for taps 390b as indicated in
Although transformers 302, 322, 342, 362, and/or 382 described above include specified numbers of taps and inputs, transformers 302, 322, 342, 362, and/or 382 may include any suitable number of taps and inputs (e.g., some implementations may include more than two differential inputs and/or more than two differential outputs).
As shown in
Modifications, additions, or omissions may be made to system 100 from the scope of the disclosure. The components of system 100 may be integrated or separated. Moreover, the operations of system 100 may be performed by more, fewer, or other components. As used in this document, “each” refers to each member of a set or each member of a subset of a set.
Although the present disclosure has been described with several embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.
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Number | Date | Country | |
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20120081203 A1 | Apr 2012 | US |