Methods for Increasing RF Throughput Via Usage of Tunable Filters
Methods and devices are described for increasing RF throughput in a multiple RF paths RF transmit/receive system with a plurality RF transmit/receive systems. In one case a tunable notch filter is used to reduce channel interference between the plurality of RF transmit/receive systems.
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The present application is related to U.S. patent application Ser. No. ______ entitled “Devices and Methods for Duplexer Loss Reduction” (Attorney Docket No. PER-100-PAP) filed on even date herewith and incorporated herein by reference in its entirety. The present application is also related to U.S. patent application Ser. No. ______ entitled “Integrated Tunable Filter Architecture” (Attorney Docket No. PER-115-PAP) filed on even date herewith and incorporated herein by reference in its entirety.
The present application may be related to U.S. Pat. No. 6,804,502, issued on Oct. 12, 2004 and entitled “Switch Circuit and Method of Switching Radio Frequency Signals”, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. Pat. No. 7,910,993, issued on Mar. 22, 2011 and entitled “Method and Apparatus for use in improving Linearity of MOSFET's using an Accumulated Charge Sink”, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 13/797,779 entitled “Scalable Periphery Tunable Matching Power Amplifier”, filed on Mar. 3, 2013, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to International Application No. PCT/US2009/001358, entitled “Method and Apparatus for use in digitally tuning a capacitor in an integrated circuit device”, filed on Mar. 2, 2009, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 13/595,893, entitled “Method and Apparatus for Use in Tuning Reactance in a Circuit Device”, filed on Aug. 27, 2012, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 14/042,312, filed on Sep. 30, 2013, entitled “Methods and Devices for Impedance Matching in Power Amplifier Circuits”, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. Pat. No. 7,248,120, issued on Jul. 24, 2007, entitled “Stacked Transistor Method and Apparatus”, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 13/828,121, filed on Mar. 14, 2013, entitled “Autonomous Power Amplifier Optimization”, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 13/967,866 entitled “Tunable Impedance Matching Network”, filed on Aug. 15, 2013, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 13/797,686 entitled “Variable Impedance Match and Variable Harmonic Terminations for Different Modes and Frequency Bands”, filed on Mar. 12, 2013, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 14/042,331 entitled “Methods and Devices for Thermal Control in Power Amplifier Circuits”, filed on Sep. 30, 2013, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 13/829,946 entitled “Amplifier Dynamic Bias Adjustment for Envelope Tracking, filed on Mar. 14, 2013, the disclosure of which is incorporated herein by reference in its entirety. The present application may also be related to U.S. patent application Ser. No. 13/830,555 entitled “Control Systems and Methods for Power Amplifiers Operating in Envelope Tracking Mode”, filed on Mar. 14, 2013, the disclosure of which is incorporated herein in its entirety.
BACKGROUND1. Field
The present teachings relate to RF (radio frequency) circuits. More particularly, the present teachings relate to methods for increasing data throughput in an RF transmit/receive system.
2. Description of Related Art
Radio frequency (RF) devices, such as cell phone transmitters, are becoming increasingly complex due to additional frequency bands, more complex modulation schemes, higher modulation bandwidths, and the introduction of data throughput improvement schemes such as simultaneous RF transmission and/or reception within a same or different, but closely spaced, bands or channels within a band (e.g. voice, data), and aggregate transmission wherein information is multiplexed over parallel RF transmissions. Due to the high integration and closely spaced transmit/receive paths of a front-end stage used in such RF devices, RF signal interference from neighboring paths, either receive or transmit, can influence RF signal of a transmit/receive path (e.g. via intermodulation) and therefore affect (e.g. reduce) a corresponding throughput by increasing spectrum usage within a frequency band and therefore limiting the number of simultaneous RF transmission and/or reception (e.g. number of usable channels) within a frequency band.
SUMMARYAccording to a first aspect of the present disclosure, a radio frequency (RF) circuital arrangement is presented, the arrangement comprising: a first transmit/receive system comprising a first transmit path configured to transmit a first transmit RF signal at a first transmit/receive port, and a first receive path configured to receive a first receive RF signal at the first transmit/receive port; a second transmit/receive system comprising a second transmit path configured to transmit a second transmit RF signal at a second transmit/receive port, and a second receive path configured to receive a second receive RF signal at the second transmit/receive port, and one or more tunable notch filters configured to reduce a radio frequency interference of a transmit/receive system of the first and second transmit/receive systems over the other transmit/receive system.
According to second aspect of the present disclosure, a radio frequency (RF) integrated circuit is presented, the integrated circuit comprising: an RF switch comprising a first switch terminal and a second switch terminal; a RF tunable notch filter comprising a first port and a second port, wherein in a first configuration of the RF integrated circuit the first port is connected to the first switch terminal and the second port is connected to the second switch terminal, and in a second configuration of the RF integrated circuit the first port is connected to the second switch terminal; a first input/output terminal connected to the first switch terminal; a second input/output terminal connected to the second port, and a control terminal, wherein during operation, a control signal at the control terminal of the RF integrated circuit is configured to tune the RF tunable notch filter and/or control the RF switch to enable/disable a current flow through the RF tunable notch filter.
According to a third aspect of the present disclosure, a method for reducing radio frequency (RF) interference in an RF circuital arrangement is presented, the method comprising: providing a plurality of RF transmit/receive systems coupled to a plurality RF antennas; connecting in a path of a first RF transmit/receive system of the plurality of RF transmit/receive systems one or more RF tunable notch filters; adjusting an RF tunable notch filter of the one or more RF tunable notch filters based on a characteristic of a transmit/receive RF signal of an RF transmit/receive system of the plurality of RF transmit/receive systems other than the first RF transmit/receive system, and based on the adjusting, reducing an RF interference of the transmit/receive RF signal over the first RF transmit/receive system.
According to a fourth aspect of the present disclosure, a radio frequency (RF) circuital arrangement is presented, the arrangement comprising: a transmit path configured to transmit, during a transmit mode of operation of the RF circuital arrangement, a transmit RF signal at a transmit/receive port of the RF circuital arrangement; a receive path configured to receive, during a receive mode of operation of the RF circuital arrangement, a receive RF signal at the transmit/receive port, and a tunable notch filter configured to reduce a radio frequency interference of the transmit RF signal over the receive RF signal, wherein during operation, the RF circuital arrangement is configured to simultaneously operate in the transmit and receive modes of operation.
According to a fifth aspect of the present disclosure a method for reducing radio frequency (RF) interference in an RF circuital arrangement is presented, the method comprising: providing an RF transmit path to transmit a transmit RF signal over an antenna; providing an RF receive path to receive a receive RF signal over the antenna; coupling a tunable notch tilter to the RF transmit or the RF receive path; adjusting the tunable notch filter based on a frequency of operation of the transmit RF signal, and based on the adjusting, reducing an RF interference of the transmit RF signal over the receive RF signal.
The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present disclosure and, together with the description of example embodiments, serve to explain the principles and implementations of the disclosure.
Throughout this description, embodiments and variations are described for the purpose of illustrating uses and implementations of the inventive concept. The illustrative description should be understood as presenting examples of the inventive concept, rather than as limiting the scope of the concept as disclosed herein.
As used in the present disclosure, the terms “switch ON” and “activate” may be used interchangeably and can refer to making a particular circuit element electronically operational. As used in the present disclosure, the terms “switch OFF” and “deactivate” may be used interchangeably and can refer to making a particular circuit element electronically non-operational. As used in the present disclosure, the terms “amplifier” and “power amplifier” may be used interchangeably and can refer to a device that is configured to amplify a signal input to the device to produce an output signal of greater magnitude than the magnitude of the input signal.
The present disclosure describes electrical circuits in electronics devices (e.g., cell phones, radios) having a plurality of devices, such as for example, transistors (e.g., MOSFETs). Persons skilled in the art will appreciate that such electrical circuits comprising transistors can be arranged as amplifiers. As described in a previous disclosure (U.S. patent application Ser. No. 13/797,779, incorporated herein by reference in its entirety), a plurality of such amplifiers can be arranged in a so-called “scalable periphery” (SP) architecture of amplifiers where a total number (e.g., 64) of amplifier segments are provided. Depending on the specific requirements of an application, the number of active devices (e.g., 64, 32, etc.), or a portion of the total number of amplifiers (e.g. 1/64, 2/64, 40% of 64, etc. . . . ), can be changed for each application. For example, in some instances, the electronic device may desire to output a certain amount of power, which in turn, may require 32 of 64 SP amplifier segments to be used. In yet another application of the electronic device, a lower amount of output power may be desired, in which case, for example, only 16 of 64 SP amplifier segments are used. According to some embodiments, the number of amplifier segments used can be inferred by a nominal desired output power as a function of the maximum output power (e.g. when all the segments are activated). For example, if 30% of the maximum output power is desired, then a portion of the total amplifier segments corresponding to 30% of the total number of segments can be enabled. The scalable periphery amplifier devices can be connected to corresponding impedance matching circuits. The number of amplifier segments of the scalable periphery amplifier device that are turned on or turned off at a given moment can be according to a modulation applied to an input RF signal, a desired output power, a desired linearity requirement of the amplifier or any number of other requirements.
The term “amplifier” as used in the present disclosure is intended to refer to amplifiers comprising single or stacked transistors configured as amplifiers, and can be used interchangeably with the term “power amplifier (PA)”. Such terms can refer to a device that is configured to amplify a signal input to the device to produce an output signal of greater magnitude than the magnitude of the input signal. Stacked transistor amplifiers are described for example in U.S. Pat. No. 7,248,120, issued on Jul. 24, 2007, entitled “Stacked Transistor Method and Apparatus”, the disclosure of which is incorporated herein by reference in its entirety. Such amplifier and power amplifiers can be applicable to amplifiers and power amplifiers of any stages (e.g., pre-driver, driver, final), known to those skilled in the art.
As used in the present disclosure, the term “mode” can refer to a wireless standard and its attendant modulation and coding scheme or schemes. As different modes may require different modulation schemes, these may affect required channel bandwidth as well as affect the peak-to-average-ratio (PAR), also referred to as peak-to-average-power-ratio (PAPR), as well as other parameters known to the skilled person. Examples of wireless standards include Global System for Mobile Communications (GSM), code division multiple access (CDMA), Worldwide Interoperability for Microwave Access (WiMAX), Long Term Evolution (LTE), as well as other wireless standards identifiable to a person skilled in the art. Examples of modulation and coding schemes include binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), quadrature amplitude modulation (QAM), 8-QAM, 64-QAM, as well as other modulation and coding schemes identifiable to a person skilled in the art.
As used in the present disclosure, the term “band” can refer to a frequency range. More in particular, the term “band” as used herein refers to a frequency range that can be defined by a wireless standard such as, but not limited to, wideband code division multiple access (WCDMA) and long term evolution (LTE).
As used in the present disclosure, the term “channel” can refer to a frequency range. More in particular, the term “channel” as used herein refers to a frequency range within a band. As such, a band can comprise several channels used to transmit/receive a same wireless standard.
As previously mentioned, a transmit/receive RF signal can be in correspondence of a frequency band associated to a wireless standard (e.g. mode), and in turn, the frequency band can comprise a plurality of channels which can be used to transmit/receive an RF signal according the defined modulation scheme of the wireless standard.
According to an embodiment of the present disclosure, a method for reducing such interference effect while maintaining a higher number of transmit/receive channels is provided. Such method uses a tunable filter in the receive and/or transmit path to further immune the two paths with respect to each other. For example, a tunable band-reject filter tuned at a center frequency of an RF transmit signal (e.g. f1T, f2T, f3T) can be placed in the receive path to reject a transmit RF frequency in the receive path such as depicted in
The person skilled in the art readily knows that the system block diagram depicted in
With further reference to
The duplexer units (130) and (330) of
In a first mode of operation of the multiple RF paths transmit/receive system (300) of
According to a second mode of operation of the multiple RF paths transmit/receive system (300)) of
According to an embodiment of the present disclosure, a tunable notch filter, such as a narrow tunable band-reject filter, can be placed (e.g. via a series and/or a shunt connection/coupling, such as depicted in
As it is well known to the person skilled in the art, intermodulation between two signals at differing frequencies (f1, f2) can engender sideband signals centered around each of the frequencies and distant from each frequency by the difference of the frequencies (f1, f2), as depicted in
The teachings according to the present disclosure provide methods and apparatus to reduce such interference in a multiple RF paths transmit/receive system, such as the exemplary system depicted in
It should be noted that when the exact same bands (e.g. transmit band) are being used in both transmit/receive systems (e.g. as per system 500 of
Although the exemplary configuration depicted by
In the embodiment according to the present disclosure as depicted in
According to a further embodiment of the present disclosure, the combination of tunable notch filter (e.g. 545a, 545b, 535) and switch (e.g. (725a-c) can be monolithically integrated within a same integrated circuit as depicted in
The tunable notch filters described in the various embodiments according to the present disclosure can be constructed using one or more variable reactive elements, such as variable capacitors and variable inductors. Digitally tunable capacitors (DTC) and/or digitally tunable inductors, as described in, for example. International Application No. PCT/US2009/001358 and U.S. patent application Ser. No. 13/595,893, can also be used in constructing such tunable notch filter. The person skilled in the art readily knows how to realize such tunable filters and how to select components with values (e.g. ranges of values) consistent with a desired tilter bandwidth and attenuation. As known by the person skilled in the art, such components can be partitioned into various filter stages via series and/or shunt connections, and in turn, the various filter stages can be interconnected (e.g. cascaded) via series and/or shunt connections. Some exemplary embodiments of tunable notch filters are described in the above mentioned U.S. application Ser. No. ______ entitled “Integrated Tunable Filter Architecture” (Attorney Docket No. PER-115-PAP) filed on even date herewith and incorporated herein by reference in its entirety.
Although the various exemplary embodiments of the present disclosure are based on a multi-path transmit/receive system showing two separate transmit/receive systems (e.g. (140, 120, 130, 110) and (140, 320, 330, 310)), each with a dedicated transmit/receive antenna (e.g. (110, 310), such limitation of two transmit/receive systems is mainly exemplary in nature and not intended to limit the scope of the invention which can certainly be extended to more than two such transmit/receive systems, each with a dedicated transmit/receive antenna. In such configuration, a controller unit can tune the various tunable notch filters according to the known signal spectra used in the various transmit/receive systems. Such spectra can comprise not only known operating frequencies (e.g. channel frequencies) associated to the various transmitted and received signals within the various transmit/receive systems, but also can comprise various harmonics and intermodulation products thereof which alone or in combination can affect operation of one or more of the various transmit/receive systems. Additionally, each transmit/receive system can comprise more than one transmit/receive path, as a plurality of parallel transmit/receive paths can be connected to an antenna via a dedicated antenna switch, as typically done in current RF front-end stages used in current cellular devices.
By way of further example and not limitation, any switch or switching circuitry of the present disclosure, such as switches (725a-c) of
Although FETs (e.g. MOSFETs) can be used to describe transistor and stacked transistor switches used in the various embodiments of the present disclosure, a person skilled in the art would recognize that either P-type or N-type MOSFETs may be used. The skilled person would also recognize that other types of transistors such as, for example, bipolar junction transistors (BJTs) can be used instead or in combination with the N-type or P-type MOSFETs. Furthermore, a person skilled in the art will also appreciate the advantage of stacking more than two transistors, such as three, four, five or more, provide on the voltage handling performance of the switch. This can for example be achieved when using non bulk-Silicon technology, such as insulated Silicon on Sapphire (SOS) technology and silicon on insulated (SOI) technology. In general, the various switches used in the various embodiments of the present disclosure, including when monolithically integrated with a tunable notch filter, such as depicted in
The examples set forth above are provided to give those of ordinary skill in the art a complete disclosure and description of how to make and use the embodiments of the present disclosure, and are not intended to limit the scope of what the inventors regard as their disclosure. Modifications of the above described modes for carrying out the disclosure may be used by persons of skill in the art, and are intended to be within the scope of the following claims. All patents and publications mentioned in the specification may be indicative of the levels of skill of those skilled in the art to which the disclosure pertains. All references cited in this disclosure are incorporated by reference to the same extent as if each reference had been incorporated by reference in its entirety individually.
It is to be understood that the disclosure is not limited to particular methods or systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. The term “plurality” includes two or more referents unless the content clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure pertains.
A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the present disclosure. Accordingly, other embodiments are within the scope of the following claims.
Claims
1. A radio frequency (RF) circuital arrangement comprising:
- a first transmit/receive system comprising a first transmit path configured to transmit a first transmit RF signal at a first transmit/receive port, and a first receive path configured to receive a first receive RF signal at the first transmit/receive port;
- a second transmit/receive system comprising a second transmit path configured to transmit a second transmit RF signal at a second transmit/receive port, and a second receive path configured to receive a second receive RF signal at the second transmit/receive port, and
- one or more tunable notch filters configured to reduce a radio frequency interference of a transmit/receive system of the first and second transmit/receive systems over the other transmit/receive system.
2. The RF circuital arrangement of claim 1, wherein a tunable notch filter of the one or more tunable notch filters is connected between a transmit/receive port of the first and the second transmit/receive ports and a duplexer unit in correspondence of the transmit/receive port.
3. The RF circuital arrangement of claim 1, wherein a tunable notch filter of the one or more tunable notch filters is connected between a duplexer unit of a transmit/receive system of the first and the second transmit/receive systems and an input RF amplifier of the transmit/receive system.
4. The RF circuital arrangement of claim 1, wherein the tunable notch filter of the one or more tunable notch filters is connected between a transmit amplifier of a transmit/receive system of the first and the second transmit/receive systems and a duplexer unit in correspondence of the transmit/receive system.
5. The RF circuital arrangement of any one of claims 2-4, wherein the tunable notch filter is connected in a series and/or a shunt configuration.
6. The RF circuital arrangement of claim 1, further comprising one or more RF switches, wherein the one or more RF switches are configured to enable and/or disable an effect of the one or more tunable notch filters over a transmit/receive system of the first and second transmit/receive systems.
7. The RF circuital arrangement of claim 6, wherein a switch of the one or more RF switches is connected in parallel to a tunable notch filter of the one or more tunable notch filters.
8. The RF circuital arrangement of claim 7, wherein the switch is connected between a first and a second input/output terminal of the tunable notch filter.
9. The RF circuital arrangement of claim 6, wherein a switch of the one or more switches is connected in series to a tunable notch filter of the one or more tunable notch filters.
10. The RF circuital arrangement of claim 7 or claim 9, wherein a switch of the one or more switches comprises stacked transistors.
11. The RF circuital arrangement of claim 1, wherein a tunable notch filter of the one or more tunable notch filters is a band-reject filter configured to reject a frequency band in correspondence of a first transmit/receive channel and to pass a frequency band in correspondence of a second transmit/receive channel adjacent to the first transmit/receive channel.
12. The RF circuital arrangement of claim 11, wherein the frequency band is in correspondence of one of: a) a frequency of operation of a transmit RF signal of the first and the second transmit RF signals, b) a harmonic of a), and c) an intermodulation product of any combination of a) and b).
13. The RF circuital arrangement of claim 1, wherein a tunable notch filter of the one or more tunable notch filters comprises one or more variable reactive elements.
14. The RF circuital arrangement of claim 13, wherein the one or more variable reactive elements are partitioned in one or more stages interconnected via series and/or shunt connections.
15. The RF circuital arrangement of claim 13, wherein a reactive element of the one or more variable reactive elements comprises one of: a) a digitally tunable capacitor, and b) a digitally tunable inductor.
16. The RF circuital arrangement of claim 1, wherein during operation of the circuital arrangement, the first and the second transmit/receive systems are adapted to simultaneously transmit and/or receive an RF signal over a channel of a plurality of channels of a frequency band.
17. The RF circuital arrangement of claim 1, wherein the first transmit/receive port comprises a first transmit/receive antenna and the second transmit/receive port comprises a second transmit/receive antenna.
18. The RF circuital arrangement of claim 1, further comprising one or more transmit/receive systems similar to the first/second transmit/receive systems, wherein one or more of the one or more tunable notch filters are configured to reduce a radio frequency interference of a transmit/receive system of the RF circuital arrangement over the other transmit/receive systems of the RF circuital arrangement.
19. A radio frequency (RF) integrated circuit comprising:
- an RF switch comprising a first switch terminal and a second switch terminal;
- a RF tunable notch filter comprising a first port and a second port, wherein in a first configuration of the RF integrated circuit the first port is connected to the first switch terminal and the second port is connected to the second switch terminal, and in a second configuration of the RF integrated circuit the first port is connected to the second switch terminal;
- a first input/output terminal connected to the first switch terminal;
- a second input/output terminal connected to the second port; and
- a control terminal,
- wherein during operation, a control signal at the control terminal of the RF integrated circuit is configured to tune the RF tunable notch filter and/or control the RF switch to enable/disable a current flow through the RF tunable notch filter.
20. The RF integrated circuit of claim 19, wherein the RF tunable notch filter comprises one or more variable reactive elements.
21. The RF integrated circuit of claim 20, wherein a reactive element of the one or more variable reactive elements comprises one of: a) a digitally tunable capacitor, and b) a digitally tunable inductor.
22. The RF integrated circuit of claim 19 monolithically integrated on a same integrated circuit.
23. The RF integrated circuit of claim 22 fabricated using a technology comprising one of: a) Silicon on Sapphire, b) Silicon on Insulator, c) bulk-Silicon, and d) micro-electro-mechanical systems.
24. The RF circuital arrangement of claim 19 configured for operation in one of: a) a differential mode, and b) single-ended mode.
25. A communication device for transmitting and receiving RF signals via one or more antennas, the communication device comprising the RF circuital arrangement of claim 1 or claim 18, wherein the one or more antennas of the communication device are coupled to a plurality of transmit/receive ports of a plurality of transmit/receive systems of the RF circuital arrangement.
26. The communication device of claim 25 further comprising a transceiver unit, wherein during operation of the communication device, the transceiver unit is adapted to send/receive a plurality of transmit/receive RF signals to/from the plurality of transmit/receive systems of the RF circuital arrangement.
27. The communication device of claim 26, wherein, during operation of the communication device, the transceiver unit is adapted to control the one or more tunable notch filters based on a characteristic of one or more RF signals of the plurality of transmit/receive RF signals.
28. The communication device of claim 27, wherein the characteristic comprises a frequency spectra of the one or more RF signals.
29. The communication device of claim 28, wherein the frequency spectra comprises at least one of: a) spectra of a frequency of operation of an RF signal of the one or more RF signals, b) spectra of a harmonic of a) and c) spectra of an intermodulation product of the one or more RF signals.
30. A method for reducing radio frequency (RF) interference in an RF circuital arrangement, the method comprising:
- providing a plurality of RP transmit/receive systems coupled to a plurality RF antennas;
- connecting in a path of a first RF transmit/receive system of the plurality of RF transmit/receive systems one or more RF tunable notch filters;
- adjusting an RF tunable notch filter of the one or more RF tunable notch filters based on a characteristic of a transmit/receive RF signal of an RF transmit/receive system of the plurality of RF transmit/receive systems other than the first RF transmit/receive system; and
- based on the adjusting, reducing an RF interference of the transmit/receive RF signal over the first RF transmit/receive system.
31. The method of claim 30, further comprising:
- monitoring the characteristic of the transmit/receive RF signal;
- based on the monitoring, detecting a change of the characteristic;
- based on the detecting, further adjusting the RF tunable notch filter; and
- based on the further adjusting, maintaining a reduced RF interference of the transmit/receive RF signal over the first RF transmit/receive system.
32. The method of claim 31, further comprising:
- based on the maintaining, providing a larger operating frequency spectrum to the first transmit/receive RF system;
- based on the providing, increasing a number of transmit/receive channels available to the first transmit/receive RF system; and
- based on the increasing, increasing data throughput of the RF circuital arrangement.
33. The method of claim 30, wherein the characteristic of the transmit/receive RF signal comprises a known operating frequency of the transmit/receive RF signal.
34. The method of claim 33, wherein the known operating characteristic is in correspondence of a selected transmit/receive channel.
35. The method of claim 34, wherein selection of the selected transmit/receive channel is performed by a transceiver unit.
36. A radio frequency (RF) circuital arrangement comprising:
- a transmit path configured to transmit, during a transmit mode of operation of the RF circuital arrangement, a transmit RF signal at a transmit/receive port of the RF circuital arrangement;
- a receive path configured to receive, during a receive mode of operation of the RF circuital arrangement, a receive RF signal at the transmit/receive port, and
- a tunable notch filter configured to reduce a radio frequency interference of the transmit RF signal over the receive RF signal,
- wherein during operation, the RF circuital arrangement is configured to simultaneously operate in the transmit and receive modes of operation.
37. The RF circuital arrangement of claim 36, wherein the transmit path and the receive path are coupled to the transmit/receive port via a duplexer unit and wherein the tunable notch filter is connected between the duplexer unit and one of: a) an input RF amplifier of the receive path, b) a transmit RF amplifier of the transmit path, and c) the transmit/receive port.
38. The RF circuital arrangement of claim 36 or claim 37, wherein the tunable notch filter is connected in a series or shunt configuration.
39. The RF circuital arrangement of claim 38, further comprising an RF switch coupled to the tunable notch filter, wherein during operation of the RF circuital arrangement, the RF switch is configured to enable and/or disable an effect of the tunable notch filter over the receive RF signal.
40. The RF circuital arrangement of claim 39, wherein the switch comprises stacked transistors.
41. The RF circuital arrangement of claim 39, wherein the switch is connected in one of: a) parallel configuration and b) serial configuration to the tunable notch filter.
42. The RF circuital arrangement of claim 36, wherein the tunable notch filter is a band-reject filter configured, during operation of the RF circuital arrangement, to reject a frequency of operation of the transmit RF signal and to pass a frequency of operation of the receive RF signal.
43. The RF circuital arrangement of claim 42, wherein:
- the frequency of operation of the transmit RF signal is in correspondence of a transmit channel of a plurality of transmit channels;
- the frequency of operation of the receive RF signal is in correspondence of a receive channel of a plurality of receive channels; and
- the RF circuital arrangement is configured to operate in one or more transmit and receive channels.
44. The RF circuital arrangement of claim 36, wherein the tunable notch filter comprises one or more variable reactive elements.
45. The RF circuital arrangement of claim 44, wherein a reactive element of the one or more variable reactive elements comprises one of: a) a digitally tunable capacitor, and b) a digitally tunable inductor.
46. The RF circuital arrangement of claim 36, wherein the transmit/receive port comprises a transmit/receive antenna.
47. A communication device for transmitting and receiving radio frequency (RF) signals via an antenna, the communication device comprising the RF circuital arrangement of claim 43, wherein the antenna of the communication device is coupled to the transmit/receive port of the RF circuital arrangement.
48. The communication device of claim 47 further comprising a transceiver unit, wherein during operation of the communication device, the transceiver unit is configured to send the transmit RF signal and to receive the receive RF signal respectively to/from the transmit path and receive path of the RF circuital arrangement.
49. The communication device of claim 48, wherein, during operation of the communication device, the transceiver unit is adapted to control the tunable notch filter based on a transmit channel frequency and/or a receive channel frequency in correspondence of the transmit RF signal and the receive RF signal respectively.
50. A method for reducing radio frequency (RF) interference in an RF circuital arrangement, the method comprising:
- providing an RF transmit path to transmit a transmit RF signal over an antenna;
- providing an RF receive path to receive a receive RF signal over the antenna;
- coupling a tunable notch filter to the RF transmit or the RF receive path;
- adjusting the tunable notch filter based on a frequency of operation of the transmit RF signal; and
- based on the adjusting, reducing an RF interference of the transmit RF signal over the receive RF signal.
51. The method of claim 50, wherein the adjusting further comprises:
- further adjusting the tunable notch filter based on a frequency of operation of the receive RF signal.
52. The method of claim 50, wherein the frequency of operation is in correspondence of a frequency of a selected transmit channel and wherein the adjusting is performed under control of a controller unit aware of the selected transmit channel.
53. The method of claim 52, wherein the controller unit is a transceiver unit.
54. The method of claim 51, wherein the adjusting is based on an intermodulation product of the frequency of operation of the transmit RF signal and the frequency of operation of the receive RF signal.
Type: Application
Filed: Feb 14, 2014
Publication Date: Aug 20, 2015
Applicant: PEREGRINE SEMICONDUCTOR CORPORATION (San Diego, CA)
Inventor: Dan William Nobbe (Crystal Lake, IL)
Application Number: 14/181,478