Patent Application
20160380604
The present disclosure relates to a hybrid transformer based duplexer system with two antenna ports.
In Radio Frequency (RF) communication systems, acoustic filters like Surface Acoustic Wave (SAW) filters, Bulk Acoustic Wave (BAW) filters and Film Bulk Acoustic Resonator (FBAR) filters are used to provide isolation between the transmitted signal and the receiver. These acoustic filters represent a significant portion of the total RF solution Bill of Materials (BOM) cost for cellular communication systems. The replacement of these multiple acoustic filters with one tunable filter would significantly reduce the RF cost involved in the manufacture of a RF communication system.
A center tapped hybrid transformer can be used as a duplexer to provide isolation between the transmitted signal and the receiver. However, the center tapped hybrid transformer causes high transmit insertion loss and receive insertion loss. It is advantageous to minimize these losses in the duplexer to make it more efficient.
In the present disclosure, a Hybrid Transformer based Duplexer (HTBD) is disclosed. The HTBD comprises a first winding coupled between a power amplifier port and a first antenna port, a second winding coupled between the power amplifier port and a second antenna port. The HTBD further comprises an amplifier circuit comprising at least one input and at least one output. The HTBD further comprises a third winding coupled to the at least one input of the amplifier circuit. A first coupling is formed between the first winding and the third winding and a second coupling is formed between the second winding and the third winding. Further, the HTBD comprises a programmable phase shifter circuit coupled between the second winding and the second antenna port, wherein the programmable phase shifter is configured to shift the phase of the second signal. The HTBD further comprises a feedback circuit coupled to at least one output of the amplifier circuit. The feedback circuit is configured to generate feedback information based on the first signal and the second signal. In one embodiment, the amplifier circuit comprises a differential amplifier comprising a first input, a second input, a first output and a second output. In another embodiment, the amplifier circuit comprises a single ended amplifier comprising a first input and a first output. These embodiments are appreciated in detail in this disclosure.
In another embodiment of the disclosure, a tunable transformer based duplexer (TTBD) system is disclosed. The TTBD comprises a first winding coupled between a power amplifier port and a first antenna port and a second winding coupled between the power amplifier port and a second antenna port. The TTBD further comprises an amplifier circuit comprising at least one input and at least one output. Further, the TTBD comprises a third winding comprising a first terminal and a second terminal. A first coupling is formed between the first winding and the third winding. A second coupling is formed between the second winding and the third winding. The TTBD further comprises a tunable capacitance between the first terminal and the second terminal of the third winding. The TTBD also comprises a programmable phase shifter circuit coupled between the second winding and the second antenna port, wherein the programmable phase shifter circuit is configured to shift the phase of the second signal. In one embodiment, the amplifier circuit comprises a differential amplifier comprising a first input, a second input, a first output and a second output. In another embodiment, the amplifier circuit comprises a single ended amplifier comprising a first input and a first output. These embodiments are appreciated in detail in this disclosure.
The present disclosure will now be described with reference to the attached figures, wherein like reference numerals are used to refer to like elements throughout, and wherein the illustrated structures and devices are not necessarily drawn to scale. As utilized herein, terms “component,” “system,” “interface,” “decoder” and the like are intended to refer to a circuit related entity, hardware, software (e.g., in execution), or firmware or a combination thereof. As another example, a component can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, in which the electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processors. The one or more processors can be internal or external to the apparatus and can execute at least a part of the software or firmware application. As yet another example, a component can be an apparatus that provides specific functionality through electronic components without mechanical parts; the electronic components can include one or more processors therein to execute software and/or firmware that confer(s), at least in part, the functionality of the electronic components.
Prior arts
The present disclosure discloses circuitry and a method to minimize the insertion loss in a transformer based duplexer system. A Hybrid Transformer based Duplexer (HTBD) is disclosed.
The DLNA 204 is in the receive signal flow path of the HTBD and hence in some embodiments, it can be referred as a receiving amplifier. The power amplifier is in the transmit signal flow path of the HTBD and hence in some embodiments, it can be referred as a transmitting amplifier port.
In another embodiment, a DLNA 204 is replaced by a single ended low noise amplifier. The working of the HTBD comprising the amplifier circuit is appreciated in
In RF communication, due to multiple path propagation and other environmental factors, the signals received at the first antenna port 208 and the second antenna port 210 may not exactly have the same phase. In such cases, it is advantageous to configure the phase shifter circuit 211 such that the second signal received at the second antenna port 210 is exactly 180 degrees out of phase with respect to the first signal received at the first antenna port 208. Having a programmable phase shifter enables the HTBD to operate at a multitude of frequencies, because the received signals arrive at the two antennas at phases which vary with frequency.
The HTBD system 300 of
In some embodiments, the feedback circuit 314 is coupled to the baseband components, as it may be easier and more efficient to calculate the phase difference between the first signal and the second signal in baseband. One way of generating the feedback information 313 is by independently measuring the phase of each received signal (the first signal and the second signal) and calculating the phase difference between the two received signals. For example, one of the signal paths of the DLNA 204 can be biased in the off-state, and the phase of the received signal in the signal path biased in the on-state can be calculated. This is achieved by the switches 315(a) and 315(b) at the first output 213(a) and the second output 213(b) of the DLNA 204. While in
The programmable phase shifter circuit 311, in one embodiment, is calibrated initially to shift the phase of the second signal based on the feedback information 313 received from the feedback circuit 314. In another embodiment, the programmable phase shifter circuit 311 is calibrated periodically. In another embodiment, the feedback circuit 314 is configured to continuously generate feedback information 313 based on the first signal and the second signal received at the first antenna port 208 and the second antenna port 210. The programmable phase shifter circuit 311 is configured to adaptively change the phase of the second signal based on the feedback information 313 received from the feedback circuit 314.
In RF communication, it is important to filter out the out of band blockers. The out of band blockers cause a degradation of the desired signal. If the out of band blockers have a high power when compared to the in-band signal (desired signal), the desired signal may be buried under the high powered out of band blockers which may result in amplifier saturation and tougher decoding of the desired signal. Therefore, it is advantageous to filter out the out of band blockers.
The present disclosure discloses a Tunable Transformer Based Duplexer (TTBD) to provide isolation between the transmit signal and the receive signal and also to provide out of band rejection of the receive blockers.
During transmission, the first antenna port 408 is configured to transmit the transmit signal from the power amplifier port 406 through the antenna 407. The second antenna port 410 is configured to transmit the transmit signal from the power amplifier port 406 through the antenna 409. During reception, the first antenna port 408 is configured to receive a first signal via the antenna 407. The second antenna port 410 is configured to receive a second signal via the antenna 409.
The phase shifter circuit 411 is coupled between the second winding 402 and the second antenna port 410. The phase shifter circuit 411 is configured to shift the phase of the second signal received at the second antenna port 410. The phase shifter circuit 411 shifts the phase of the second signal in such a way that the first signal received and the second signal received are summed at the DLNA 404.
The third winding 403 has an inductance. The tunable capacitor 416 can be tuned to a desired value such that a tunable band-pass filtering (LC filter) is formed to filter out the out of band blockers. Thus, the TTBD system provides a very low insertion loss as well as broadband replacement of the expensive acoustic filter based duplexers.
Although the disclosure has been illustrated and described with respect to one or more implementations, alterations and/or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims.
One or more of the operations described can constitute computer readable instructions stored on one or more computer readable media, which if executed by a computing device, will cause the computing device to perform the operations described. The order in which some or all of the operations are described should not be construed as to imply that these operations are necessarily order dependent. Alternative ordering will be appreciated by one skilled in the art having the benefit of this description. Further, it will be understood that not all operations are necessarily present in each embodiment provided herein.
Moreover, in particular regard to the various functions performed by the above described components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising”.
Examples can include subject matter such as a method, means for performing acts or blocks of the method, at least one machine-readable medium including instructions that, when performed by a machine cause the machine to perform acts of the method or of an apparatus or system for concurrent communication using multiple communication technologies according to embodiments and examples described herein.
Example 1 is a hybrid transformer based duplexer system, comprising: a transmitting amplifier port; a receiving amplifier; a first antenna port and a second antenna port; a first winding coupled between the transmitting amplifier port and the first antenna port; a second winding coupled between the transmitting amplifier port and the second antenna port; a third winding that couples the receiving amplifier to both the first winding and the second winding; and a programmable phase shifter coupled between the second winding and the second antenna port.
Example 2 is a hybrid transformer duplexer system including the subject matter of example 1, including or omitting elements, wherein the first winding is configured to convey a first transmit signal from the transmitting amplifier port to the first antenna port and to convey a first receive signal from the first antenna port to the third winding.
Example 3 is a hybrid transformer duplexer system including the subject matter of examples 1-2, including or omitting elements, wherein the second winding is configured to convey a second transmit signal from the transmitting amplifier port to the second antenna port and to convey a second receive signal from the second antenna port to the third winding.
Example 4 is a hybrid transformer duplexer system including the subject matter of examples 1-3, including or omitting elements, wherein the third winding is configured to convey the first receive signal, which have been received by the first antenna and have been conveyed through the first winding, to the receiving amplifier and wherein the third winding is configured to convey the second receive signal, which have been received by the second antenna and have been conveyed through the second winding, to the receiving amplifier.
Example 5 is a hybrid transformer duplexer system including the subject matter of examples 1-4, including or omitting elements, wherein the programmable phase shifter is configured to shift the phase of the second receive signal such that the first receive signal and the second receive signal constructively interfere at an input of the receiving amplifier.
Example 6 is a hybrid transformer duplexer system including the subject matter of examples 1-5, including or omitting elements, further comprising: a feedback circuit coupled between an output of the receiving amplifier and an input of the programmable phase shifter.
Example 7 is a hybrid transformer duplexer system including the subject matter of examples 1-6, including or omitting elements, wherein the programmable phase shifter is configured to shift the phase of the second receive signal based on feedback information obtained from the feedback circuit.
Example 8 is a hybrid transformer duplexer system including the subject matter of examples 1-7, including or omitting elements, wherein the receiving amplifier comprises a differential amplifier comprising a first input, a second input, a first output and a second output.
Example 8 is a hybrid transformer duplexer system including the subject matter of examples 1-7, including or omitting elements, wherein the receiving amplifier comprises a differential amplifier comprising a first input, a second input, a first output and a second output.
Example 9 is a hybrid transformer duplexer system including the subject matter of examples 1-8, including or omitting elements, wherein the receiving amplifier comprises a single ended amplifier comprising a first input and a first output.
Example 10 is a tunable transformer based duplexer system, comprising: a first antenna port and a second antenna port; a first winding coupled between a transmitting port and the first antenna port, wherein the first antenna port is configured to receive a first signal; a second winding coupled between the transmitting port and the second antenna port, wherein the second antenna port is configured to receive a second signal; a receiving amplifier comprising at least one input and at least one output; a third winding comprising a first terminal and a second terminal, wherein the third winding is coupled to the at least one input of the receiving amplifier; wherein a first coupling is formed between the first winding and the third winding; wherein a second coupling is formed between the second winding and the third winding; a tunable capacitor coupled between the first terminal and the second terminal of the third winding; and a programmable phase shifter coupled between the second winding and the second antenna port, wherein the programmable phase shifter is configured to shift a phase of the second signal.
Example 11 is a tunable transformer duplexer system including the subject matter of example 10, including or omitting elements, wherein the third winding and the tunable capacitor together form a band-pass filter.
Example 12 is a tunable transformer duplexer system including the subject matter of examples 10-11, including or omitting elements, further comprising: a transmitting amplifier comprising an output coupled to the transmitting port and an input configured to receive a transmit signal.
Example 13 is a tunable transformer duplexer system including the subject matter of examples 10-12, including or omitting elements, wherein the first antenna port is further configured to convey signals from the transmitting amplifier to the first antenna port; and wherein the second antenna port is further configured to convey signals from the transmitting amplifier to the first antenna port.
Example 14 is a tunable transformer duplexer system including the subject matter of examples 10-13, including or omitting elements, wherein the programmable phase shifter is configured to shift the phase of the second signal to generate a phase shifted second signal, such that the phase shifted second signal is 180 degrees out of phase with the first signal.
Example 15 is a tunable transformer duplexer system including the subject matter of examples 10-14, including or omitting elements, wherein the programmable phase shifter is configured to shift the phase of the second signal to generate a phase shifted second signal, such that the first signal at the first terminal of the third winding is 180 degrees out of phase with the second signal at the second terminal of the third winding.
Example 16 is a tunable transformer duplexer system including the subject matter of examples 10-15, including or omitting elements, further comprising: a feedback circuit coupled to the at least one output of the receiving amplifier, wherein the feedback circuit is configured to generate a feedback information based on the first signal and the second signal.
Example 17 is a tunable transformer duplexer system including the subject matter of examples 10-16, including or omitting elements, wherein the programmable phase shifter is configured to shift the phase of the second signal based on the feedback information obtained from the feedback circuit.
Example 18 is a tunable transformer duplexer system including the subject matter of examples 10-17, including or omitting elements, wherein the receiving amplifier comprises a differential amplifier comprising a first input, a second input, a first output and a second output.
Example 19 is a tunable transformer duplexer system including the subject matter of examples 10-18, including or omitting elements, wherein the receiving amplifier comprises a single ended amplifier comprising a first input and a first output.
Example 20 is a method of operating a transformer based duplexer system comprising a first winding coupled between a transmitting port and a first antenna port, a second winding coupled between the transmitting port and a second antenna port, a receiving amplifier comprising at least one input and at least one output, and a third winding coupled between the input of the receiving amplifier and both the first winding and the second winding, the method comprising: receiving, by the first antenna port, a first signal; receiving, by the second antenna port, a second signal; shifting, by a programmable phase shifter, a phase of the second signal to generate a phase shifted second signal; coupling the first signal between the first winding and the third winding; and coupling the phase shifted second signal between the second winding and the third winding.
Example 21 is a method including the subject matter of example 20, including or omitting elements, further comprising: generating, by a feedback circuit, feedback information based on the first signal and the second signal; and filtering, by a capacitance and the third winding to which it is coupled, out of band blockers.
Example 22 is a method including the subject matter of example 20-21, including or omitting elements, wherein the shifting the phase of the signal, by a programmable phase shifter circuit, is based on the generated feedback information.
Example 23 is a method including the subject matter of example 20-22, including or omitting elements, wherein the phase shifted second signal is 180 degrees out of phase with the first signal.
Example 24 is a hybrid transformer duplexer system to optimize a transmit insertion loss and a receive insertion loss, the hybrid transformer based duplexer system comprising: a first winding coupled between a power amplifier port and a first antenna port, wherein the first antenna port is configured to receive a first signal; a second winding coupled between the power amplifier port and a second antenna port, wherein the second antenna port is configured to receive a second signal; an amplifier circuit comprising at least one input and at least one output; a third winding coupled to the at least one input of the amplifier circuit, wherein a first coupling is formed between the first winding and the third winding, and wherein a second coupling is formed between the second winding and the third winding; and a programmable phase shifter circuit coupled between the second winding and the second antenna port, wherein the programmable phase shifter circuit is configured to shift a phase of the second signal.
Example 25 is a hybrid transformer duplexer system including the subject matter of example 24, including or omitting elements, further comprising: a power amplifier comprising an output coupled to the power amplifier port and an input coupled to a transmit port and configured to receive a transmit signal.
Example 26 is a hybrid transformer duplexer system including the subject matter of examples 24-25, including or omitting elements, wherein the first antenna port is further configured to transmit the transmit signal from the power amplifier port; and wherein the second antenna port is further configured to transmit the transmit signal from the power amplifier port.
Example 27 is a hybrid transformer duplexer system including the subject matter of examples 24-26, including or omitting elements, wherein the programmable phase shifter circuit is configured to shift the phase of the second signal to generate a phase shifted second signal, such that the phase shifted second signal is 180 degrees out of phase with the first signal.
Example 28 is a hybrid transformer duplexer system including the subject matter of examples 24-27, including or omitting elements, further comprising a feedback circuit coupled to the at least one output of the amplifier circuit, wherein the feedback circuit is configured to generate a feedback information based on the first signal and the second signal.
Example 29 is a hybrid transformer duplexer system including the subject matter of examples 24-28, including or omitting elements, wherein the programmable phase shifter circuit is configured to shift the phase of the second signal based on the feedback information obtained from the feedback circuit.
Example 30 is a hybrid transformer duplexer system including the subject matter of examples 24-29, including or omitting elements, wherein the feedback information generated by the feedback circuit is based on a determined phase difference between the first signal and the second signal.
Example 31 is a hybrid transformer duplexer system including the subject matter of examples 24-30, including or omitting elements, wherein the amplifier circuit comprises a differential amplifier comprising a first input, a second input, a first output and a second output.
Example 32 is a hybrid transformer duplexer system including the subject matter of examples 24-31, including or omitting elements, wherein the amplifier circuit comprises a single ended amplifier comprising a first input and a first output.
