The subject matter disclosed herein relates generally to duplexers for use in communications networks. More particularly, the subject matter disclosed herein relates to duplexers used in conjunction with communications antennas.
In communications systems, duplexers provide the ability to receive and transmit signals while using the same antenna. In a typical transmission operation, only signals of a designated transmission frequency are passed to an antenna, which transmits the signal as a radio signal into the air. In a typical receiving operation, a signal received by an antenna is transmitted to the duplexer to select only a signal of the designated frequency. A duplexer uses resonant circuits to isolate a transmitter from a receiver for allowing the transmitter and the receiver to operate on the same antenna at the same time without the transmitter adversely affecting the receiver. Duplexers use filters, such as various pass band filters and notches to accomplish isolation and continuity in signal transfer. In duplexer operation, filters must pass the desired signal while rejecting as much as possible of the undesired signals.
The increased diversity in the functionality of mobile phones has resulted in an increase in the complexity of duplexer design. For example, increased mobile phone functions such as dual mode (e.g., a combination of an analog mode and a digital mode, or a combination of digital modes, such as TDMA or CDMA), and a dual band (e.g., a combination of an 800 MHz band and a 1.9 GHz band, or a combination of a 900 MHz band and a 1.8 GHz band or a 1.5 GHz band) have been increasing the complexity of mobile phone architecture and circuitry. Increased implementation of frequency related functions affect antenna bandwidth. Antenna bandwidth is generally the range of frequencies over which the antenna can operate while some other characteristic remains in a given range. Therefore, increased frequency ranges increase demand for performance over a number of frequency channels, or a wide bandwidth antenna. Moreover, to support these multiple, diverse functions while maintaining proper isolation and reliable signal transfer between transmitter and receiver operations, present communication devices use fixed, redundant circuitry, such as an increased quantity of switches and filters to compensate and broaden duplexer capabilities. Accordingly, such increased use and quantity of filters creates the need for optimizing filter performance.
There is a continuing demand for component reduction and high performance communications devices. Elimination of redundant components, functions, or circuitry is highly desired in communication electronics. Increased performance in communication devices without increasing device size or weight is similarly desirable. Further, there is a continuing need for reliable and quality signal transfer, improved transmitter-receiver isolation, and very high Q value circuitry with respect to duplexers. In addition, further considerations include polarization, tradeoffs between isolation and size, tuning precision, and transmit/receive frequency spacing for a given band versus wholesale tuning between bands.
Micro-electro-mechanical system (MEMS) technology is currently implemented for various filtering circuitry. Exemplary MEMS components that have been used for filtering include MEMS capacitors and acoustic resonators. Although there have been improvements in the development of MEMS components for filtering, there is a continuing need for improved performance and stability of these components as well as tunability for optimal performance and multi-band applications.
Therefore, room for improvement exists for improved duplexer circuitry and related components and improved MEMS components for use in duplexer circuitry.
In accordance with this disclosure, duplexers and related methods for use in communications networks are provided. Specifically, in one embodiment, a tunable radiating duplexer is provided and can include a first antenna comprising a first variable capacitor and a second antenna comprising a second variable capacitor.
It is an object of the presently disclosed subject matter to provide a tunable duplexing antenna that can combine the functions of an antenna and a duplexer (and potentially also a matching network and/or filters) and that can lower insertion losses, provide a smaller overall solutions and that may provide operation over multiple communication bands.
Some of the objects of the subject matter disclosed herein having been stated hereinabove, and which are achieved in whole or in part by the presently disclosed subject matter, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.
The features and advantages of the present subject matter will be more readily understood from the following detailed description which should be read in conjunction with the accompanying drawings that are given merely by way of explanatory and non-limiting example, and in which:
The present subject matter provides designs and methods for tunable duplexing antennas. In one aspect, the present subject matter provides a tunable radiating duplexer, generally designated 100 in
As a result, a tunable antenna of the type in
As is shown in
Alternatively and as shown in
Each different configuration provides different characteristics to tunable radiating duplexer 100. For instance, with an in-line configuration (i.e., back-to-back configuration shown in
The first transmission lines of first and second antennas 101 and 102 can be substantially parallel to the second transmission lines of first and second antennas 101 and 102, respectively. Further, in the back-to-back configuration shown in
The first transmission lines of first and second antennas 101 and 102 have different lengths d1 and d2, respectively, with the ratio approximately equal to a default transmit/receive frequency ratio. For instance, the length d1 of first transmission line T1-1 of first antenna 101 can be about 10 mm, whereas the length d2 of first transmission line T2-1 of second antenna 102 can be greater than 10 mm. Alternatively, the first transmission lines of first and second antennas 101 and 102 have substantially the same length.
First and second antennas 101 and 102 can be connected to first and second end loads 111 and 112, respectively, which can be tuning capacitors or single components with multiple terminals. As with the previous configuration, the first transmission lines of first and second antennas 101 and 102 have different lengths d1 and d2, respectively, with the ratio approximately equal to a default transmit/receive frequency ratio. For example,
Referring to
Still further alternative configurations are shown in
Regardless of the specific configuration of first and second antennas 101 and 102, tunable radiating duplexer 100 can include a tunable matching network on a circuit terminal of each of first and second antennas 101 and 102. Specifically, tunable radiating duplexer 100 can include RF circuitry coupled to either or both of the antenna circuit ports to provide amplification and filtering for transmit and receive signals. For instance, referring to
The present subject matter can be embodied in other forms without departure from the spirit and essential characteristics thereof. The embodiments described therefore are to be considered in all respects as illustrative and not restrictive. Although the present subject matter has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art are also within the scope of the present subject matter.
The presently disclosed subject matter claims the benefit of U.S. Provisional Patent Application Ser. No. 61/125,747, filed Apr. 28, 2008, the disclosure of which is incorporated herein by reference in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
5231407 | McGirr et al. | Jul 1993 | A |
6061024 | McGirr et al. | May 2000 | A |
6333719 | Varadan et al. | Dec 2001 | B1 |
6735418 | MacNally et al. | May 2004 | B1 |
7035611 | Garlepp et al. | Apr 2006 | B2 |
7116952 | Arafa | Oct 2006 | B2 |
7283793 | McKay | Oct 2007 | B1 |
7446628 | Morris | Nov 2008 | B2 |
7865149 | Han et al. | Jan 2011 | B2 |
8073400 | Gorbachov | Dec 2011 | B2 |
8106848 | Rofougaran | Jan 2012 | B2 |
8170510 | Knudsen | May 2012 | B2 |
8311496 | Rofougaran | Nov 2012 | B2 |
20010017602 | Hieb | Aug 2001 | A1 |
20020140612 | Kadambi et al. | Oct 2002 | A1 |
20020183013 | Auckland | Dec 2002 | A1 |
20040087341 | Edvardsson | May 2004 | A1 |
20040127178 | Kuffner | Jul 2004 | A1 |
20050057399 | Kipnis et al. | Mar 2005 | A1 |
20050164647 | Shamsaifar | Jul 2005 | A1 |
20060217082 | Fischer | Sep 2006 | A1 |
20070049213 | Tran | Mar 2007 | A1 |
20070222697 | Caimi | Sep 2007 | A1 |
20080107093 | Meiyappan et al. | May 2008 | A1 |
20080122723 | Rofougaran | May 2008 | A1 |
20090096517 | Huang et al. | Apr 2009 | A1 |
20090231220 | Zhang et al. | Sep 2009 | A1 |
20100053018 | Rofougaran | Mar 2010 | A1 |
20100225543 | Kakitsu et al. | Sep 2010 | A1 |
20120169565 | Morris, III | Jul 2012 | A1 |
20120286892 | Gu et al. | Nov 2012 | A1 |
20130165067 | Devries et al. | Jun 2013 | A1 |
Number | Date | Country |
---|---|---|
2 609 686 | Jul 2013 | EP |
2005 0069746 | Jul 2005 | KR |
WO 2007-025309 | Mar 2007 | WO |
WO 2012027703 | Mar 2012 | WO |
WO 2012097084 | Jun 2012 | WO |
Entry |
---|
“A Capacitively Loaded PIFA for Compact Mobile Telephone Handsets,” Rowell, IEEE Transactions on Antennas and Propagation, vol. 45, No. 5, May 1997. |
Nishio et al., “A Study of Wideband Built-In Antenna Using RF-MEMS Variable Capacitor for Digital Terrestrial Broadcasting,” Antennas and Propag. Soc. Int'l Symposium 206, IEEE Jan. 1, 2006—ISBN: 978-1-4244-0123-9. |
European Search Report/Office Action for EP Appl. No. 09739590.9 dated Nov. 7, 2011. |
International Search Report and Written Opinion for PCT/US2011/049410 dated Feb. 21, 2012. |
International Search Report and Written Opinion for PCT/US2011/064459 dated Aug. 22, 2012. |
Chinese Office Action for Application No. 200980113013.7 dated Dec. 5, 2012. |
Restriction Requirement for U.S. Appl. No. 13/219,343 dated Jul. 15, 2013. |
Chinese Office Action for Application No. 2009801130137 dated Aug. 2, 2013. |
Notice of Allowance for U.S. Appl. No. 13/219,343 dated Sep. 5, 2013. |
“Wireless Demands Focus Designers on Integration,” Nancy Friedrich, Microwaves and RF, Feb. 19, 2010. |
“Reconfigurable Antennas and RF Front Ends for Portable Wireless Devices,” David T. Auckland et al. Proceeding of the SDR 02 Technical Conference and Product Exposition. |
European Communication regarding Search Report for EP Application No. 11820747 dated Apr. 1, 2014. |
Chinese Office Action for Application No. 2014041400934240 dated Apr. 17, 2014. |
Number | Date | Country | |
---|---|---|---|
20090267851 A1 | Oct 2009 | US |
Number | Date | Country | |
---|---|---|---|
61125747 | Apr 2008 | US |