The present disclosure is related to the field of logarithmic amplifiers.
In many electronics applications, such as medical imaging, cellular communication, etc., it is desirable to be able to detect certain signals at low power levels among noise or other unwanted signals. Conventional solutions include logarithmic amplifiers (“log amps”). One characteristic of a log amp is that the output signal is a voltage proportional to the logarithm of the input signal, thereby making the log amp capable of receiving low level input signals and logarithmically amplifying them for output without amplifying the noise or other unwanted signals.
One class of log amps has multiple gain blocks, i.e., amplifiers, cascaded in series to achieve the logarithmic relationship. Due to the serial structure, differences in the performance of individual components tend to have an effect on the overall performance of the log amp. For example, the dynamic range may be limited; that is, the voltage output for very high or very low input signals does not conform to the logarithmic relationship. This can result in erroneous outputs for these extreme input values.
A logarithmic detector amplifying (LDA) system is described for use as a high sensitivity receive booster or replacement for a low noise amplifier in a receive chain of a communication device. The LDA system includes an amplifying circuit configured to receive an input signal and generate an oscillation based on the input signal, a sampling circuit coupled to the amplifying circuit and configured to terminate the oscillation based on a predetermined threshold to periodically clamp and restart the oscillation to generate a series of pulses modulated by the oscillation and by the input signal, and one or more resonant circuits coupled with the amplifying circuit and configured to establish a frequency of operation and output a signal having RF frequencies.
A new type of logarithmic detector is described herein. Examples of structures and implementations of existing logarithmic detectors are described in U.S. Pat. No. 7,911,235, issued on Mar. 22, 2011, which is incorporated herein by reference. The logarithmic detector disclosed herein is further explained below with reference to the embodiment illustrated in
A sampling circuit 112 may be coupled to the amplifying circuit 104. The sampling circuit 112 may be configured to effectively sample the current flowing in the voltage supply line to the amplifying circuit 104; once a predetermined threshold is reached, the sampling circuit 112 may act to cease the oscillation. That is, the sampling circuit 112 may be used to periodically interrupt the oscillation each time when the threshold is reached. A frequency to voltage convertor 116 may be coupled to the sampling circuit 112. The input to the frequency to voltage convertor 116 may include a series of voltage spikes, denoted as F_rep as further described herein, the frequency of which may vary substantially as the logarithm of the power of the input signal. The OUTPUT from the frequency to voltage convertor 116 may be a DC voltage that is proportional to the frequency of the input spikes.
In the case where the input signal is modulated, the OUTPUT of the frequency to voltage converter 116 may include a DC voltage component and an AC voltage component. The AC component may correspond to the input modulation and effectively be a copy of the demodulated input signal in baseband.
The embodiment of the logarithmic detector explained above may be adapted in a variety of ways to be implemented for various electronics applications. A logarithmic detector amplifier (LDA) system may be provided with certain basic properties and may be modified for suitable performance enhancement in target applications.
The isolation circuit 204 may be used to filter out power leaks, reflected signals from the LDA core 212, and other interference effects from the surrounding circuits, in particular the Tx chain, to protect the Rx chain and optimize regeneration. In particular, signals reflected back from the LDA core input to the isolation circuit 204 with an unknown phase relative to the input signal may have a detrimental effect on signal regeneration when the regeneration buildup process is synchronous. With a reflected, out of phase signal mixing with the input signal, the regeneration process cannot be achieved as desired and poor performance may result.
Leaked power may also find a way into the receiver input, likely an antenna, and be radiated as unwanted emission or EMI. The isolation circuit 204 may include a circulator for such isolation purposes. A circulator in the Rx chain may be configured to pass the Rx signals and short out unwanted leaks and reflections to ground. A typical circulator includes a ferromagnetic element, such as ferrite, to correct non-linearity. However, ferromagnetic elements are generally bulky and expensive. Other types of circulators may include nano-ferromagnetic structures and metamaterials that permit a significant size reduction. Instead of a circulator, the isolation circuit 204 may be configured to have a low noise amplifier (LNA) or any passive or active device, which may provide enhanced gain (for an active circuit), improved isolation, signal-to-noise ratio, and bandwidth. If attenuation of the input signal and/or reduction of noise figure are permitted, a resistive attenuator, a resistive splitter, a Wilkinson splitter, or a coupler may be used. The matching network 208 may be used for impedance matching and/or phase correction purposes. Based on a mechanism similar to the one explained with reference to
As mentioned earlier, the LDA system 200 may include certain basic properties of the logarithmic detector as illustrated in
Embodiments may be able to regenerate a weak to strong receive signal and amplify it selectively with minimal noise addition without any conversion of frequency that is usually associated with logarithmic amplifiers.
The isolation circuit 304 may be used to filter out power leaks, reflected signals and other interference effects from the surrounding circuits, in particular the Tx chain, to protect the Rx chain and as explained earlier to avoid the reduction of regeneration efficiency or radiated power leaks as EMI. The isolation circuit 304 may include a circulator for isolation purposes. Such a circulator in the Rx chain may be configured to pass the Rx signals and short out unwanted leaks and reflections to ground. A typical circulator may include a ferromagnetic element, such as ferrite, to correct non-linearity. However, ferromagnetic elements are generally bulky and expensive. Other types of circulators may include nano-ferromagnetic structures and metamaterials that permit a significant reduction in size. Instead of a circulator, the isolation circuit 304 may be configured to have an LNA, or any passive or active device, which may provide enhanced gain (for an active circuit), isolation, signal-to-noise ratio, and bandwidth.
The matching network 308 may be used for impedance matching and/or phase correction purposes. Based on the mechanism similar to the one explained with reference to
By configuring the resonant circuit 328 so as to output RF signals through OUTPUT B, the LDA system as illustrated in
In the conventional RF communication device such as illustrated in
Other applications may concern sub-1 GHz narrow band transceivers for use at 168 MHz, 433 MHz or 868 MHz, where the modulated signal bandwidth may be as low a few KHz.
Yet other applications may concern satellite communication, for instance, GPS at 1.5 GHz, where the received radio signal is at a very low power level. The LDA may be a candidate as a receive booster for such very low received levels and relative low data rate applications.
Yet other applications may concern a very high frequency such as the 60 GHz band where a simple electronic topology with very fast transistors is needed. The 60 GHz CMOS process may be used to design such a receive booster or an LNA replacement to provide very sensitive receivers.
Yet other applications may concern WLAN communication standards, such as IEEE 802.11a-c (with 20 MHz to 160 MHz bandwidth at 5-6 GHz), BLUETOOTH, Z-Wave, Zigbee, DECT, DECT 6.0, DECT at 2.5 GHz, and so on.
Yet other applications may concern cellular communication standards, such as AMPS, PCS, Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), CDMA, IS-95, cdmaOne, CDMA2000, Evolution-Data Optimized (EV-DO), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Digital AMPS (IS-136/TDMA), and Integrated Digital Enhanced Network (iDEN), 3G, 4G, WIMAX, LTE in various frequency bands from a few 100 MHz to a few GHz.
Yet other applications may pertain to various modulated communication signals transmitted from a wireless or wired system through cable, a power wire, a telephone wire, a fiber optic, and so on where the power of the carrier and/or the modulated signal is desired to be amplified with high sensitivity and with low addition of noise and further processed by a receiver unit.
The LDA system in
As mentioned earlier, the LDA system 300 may be implemented in the communication device of
In another embodiment, the filter 412 may be removed since the LDA system may be a selective frequency circuit due to a pulsed oscillator and amplifier that has an increased skirt ratio. This may replace the filter 412 and even exceed the out-of-band rejection performance.
In the logarithmic detector in
To output signals at the RF frequency without affecting the properties of the LDA system, the resonant circuit of the LDA system in
Three embodiments of resonant circuit configurations are described in
Referring back to
One or more resonant circuits may be used in the LDA systems illustrated herein. At least one resonant circuit may be coupled in series with the amplifying circuit at the input side or output side of the amplifying circuit. Alternatively, at least one resonant circuit may be coupled in parallel with the amplifying circuit. Yet alternatively, at least one resonant circuit may be coupled in shunt with the amplifying circuit at the input side or output side of the amplifying circuit. Furthermore, a combination of series, shunt, and parallel configurations may be employed as well. Each of the resonant circuits may be configured to include one or more components selected from the group consisting of a SAW filter, a BAW filter, a crystal filter, a ceramic filter, a mechanical filter, an LC resonator, an active RC, or a variation of RC or LC where C is replaced with a variable capacitor, e.g., a varicap, or an active component with variable capacitance. Additionally, the matching network may be configured to be coupled to the input, the RF output, or both, or can be omitted. Similarly, the isolation circuit may be configured to be coupled to the input, the RF output, or both, or may be omitted.
A first application of LDA plus PLL may be to reduce the capture frequency bandwidth and reduce the frequency bandwidth to a particular channel of the band of use, for instance, channel 3 amongst 10 channels. This topology provides an electronically adjustable band pass filter function with an adjustable or fixed bandwidth. The LDA may be useful in such an application because of its high skirt ratio (left and right frequency edge sharpness) and the fact that it may help to increase the selectivity and unwanted interference rejection of the receiver. Locking the LDA in a PLL may also make it possible to correct frequency drift with temperature so that the default oscillation frequency of the LDA core may be in relation with (N/M)*F_reference.
Other configurations of the LDA and PLL may be devised to provide additional features. The reference frequency, F_reference, that drives the PLL phase comparator may be derived from a circuit that provides synchronization with the input receive symbol rate. By doing so, the LDA may provide one quenching per symbol and in synchronicity with it. This may help to reduce the F_rep frequency to the same value as the input modulation signal. In the opposite case, F_rep must be at least twice the input modulation to meet the Nyquist criteria.
The RESONATOR INPUT may be any of a general purpose input/output port (GPIO), Serial Peripheral Interface (SPI), a Mobile Industry Processor Interface (MIPI), and so on. The RESONATOR INPUT may directly (or indirectly via other control hardware) control the one or more variable capacitors and may adjust the value of the variable capacitors based on the baseband information 1108. In effect, the GPIO/SPI/MIPI interface may adjust the variable capacitors to match the frequency of the transceiver, e.g. to set the operating frequency of the LDA, for example, to operate at different frequencies based on different communications standards or technologies (e.g., LTE, WiFi, other 802.11 standards, etc.), for different applications or processes of the communication device upon which the LDA is implemented, etc.
The configuration of the LDA in
In some instances, multiple variable capacitors may be implemented in the resonant circuit, with each variable capacitor connected to the baseband information 1108 via the RESONATOR INPUT to enable greater adjustability, e.g., greater range, in frequency adjustment. In some aspects, matching circuits and/or isolation circuits or buffers may be coupled to the INPUT and OUTPUT B, to isolate the LDA from other components in the receive chain/receiving device, for example, to provide better performance and to isolate the LDA from external circuit fluctuations, etc.
In some aspects, the resonant circuit and hence the LDA may be frequency adjusted manually, in response to one or more selections associated with the communication device upon which the LDA is implemented, in response to changing communication conditions (e.g., changes in the communication path), etc. In some aspects, baseband information 1108 may originate from a transceiver or other component of the communication device, may be generated in response to one or more selections made in association with the communication device (e.g., channel selection in configuring a WiFi connection, channel or frequency tuning of the device, etc.), and the like. It should be appreciated that the LDA in the open-loop configuration depicted in
While this document contains many specifics, these should not be construed as limitations on the scope of an invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the disclosure. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be exercised from the combination, and the claimed combination may be directed to a subcombination or a variation of a subcombination.
This application is a continuation-in-part of U.S. patent application Ser. No. 14/213,529 filed on Mar. 14, 2014, which claims benefit under 35 U.S.C. § 119(e) of Provisional U.S. Patent Application No. 61/877,218, filed Sep. 12, 2013, the contents of which are incorporated herein by reference in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
2363651 | Crosby | Nov 1944 | A |
2644081 | Donald | Jun 1953 | A |
3092779 | De Niet | Jun 1963 | A |
3199031 | Harris et al. | Aug 1965 | A |
3320530 | Pearman | May 1967 | A |
3337807 | Brown | Aug 1967 | A |
3602819 | Abbott | Aug 1971 | A |
3668535 | Lansdowne | Jun 1972 | A |
3724954 | Dreyfoos | Apr 1973 | A |
3791272 | Nobusawa | Feb 1974 | A |
3965426 | Ringland | Jun 1976 | A |
4034298 | McFadyen | Jul 1977 | A |
4042883 | Rae | Aug 1977 | A |
4160953 | Matsuura et al. | Jul 1979 | A |
4225834 | van Doorn | Sep 1980 | A |
4393514 | Minakuchi et al. | Jul 1983 | A |
4510624 | Thompson et al. | Apr 1985 | A |
4577503 | Imaino et al. | Mar 1986 | A |
4579005 | Brown | Apr 1986 | A |
4609994 | Bassim et al. | Sep 1986 | A |
4660192 | Pomatto, Sr. | Apr 1987 | A |
4882768 | Obana | Nov 1989 | A |
4972512 | Garskamp | Nov 1990 | A |
4979186 | Fullerton | Dec 1990 | A |
1424065 | Armstrong | Jul 1992 | A |
5479442 | Yamamoto | Dec 1995 | A |
5621756 | Bush et al. | Apr 1997 | A |
5697087 | Miya | Dec 1997 | A |
5771026 | Stengel, Jr. | Jun 1998 | A |
5789996 | Borodulin | Aug 1998 | A |
5818875 | Suzuki | Oct 1998 | A |
5847663 | Chasek | Dec 1998 | A |
5963842 | Kinugawa | Oct 1999 | A |
5995814 | Yeh | Nov 1999 | A |
6035002 | Schleifer | Mar 2000 | A |
6054900 | Ishida et al. | Apr 2000 | A |
6389275 | Kawashima et al. | May 2002 | B1 |
6420937 | Akatsuka et al. | Jul 2002 | B1 |
6421535 | Dickerson et al. | Jul 2002 | B1 |
6518856 | Casale et al. | Feb 2003 | B1 |
6538528 | Louzir et al. | Mar 2003 | B2 |
6553216 | Pugel | Apr 2003 | B1 |
6574287 | Swaminathan et al. | Jun 2003 | B1 |
6668165 | Cloutier | Dec 2003 | B1 |
6668619 | Yang et al. | Dec 2003 | B2 |
6670849 | Damgaard | Dec 2003 | B1 |
6671331 | Sakuma | Dec 2003 | B1 |
6684058 | Karacaoglu et al. | Jan 2004 | B1 |
7215936 | Sadowski | May 2007 | B2 |
7289784 | Nam | Oct 2007 | B2 |
7400904 | Cornwall | Jul 2008 | B2 |
7423931 | Martin et al. | Sep 2008 | B2 |
7567099 | Edwards et al. | Jul 2009 | B2 |
7567527 | Perlman | Jul 2009 | B2 |
7593696 | Fischer | Sep 2009 | B2 |
7612616 | Deng | Nov 2009 | B2 |
7683694 | Gehring | Mar 2010 | B2 |
7751857 | Beumer | Jul 2010 | B2 |
7751996 | Ardizzone et al. | Jul 2010 | B1 |
7819022 | Hope | Oct 2010 | B2 |
7848384 | Pelissier et al. | Dec 2010 | B2 |
7911235 | Brown | Mar 2011 | B2 |
8040204 | Brown | Oct 2011 | B2 |
8064864 | Rofougaran | Nov 2011 | B2 |
8144065 | Brown | Mar 2012 | B2 |
8149173 | Brown | Apr 2012 | B2 |
8164532 | Brown | Apr 2012 | B1 |
8265769 | Denison | Sep 2012 | B2 |
8326340 | Nalbantis et al. | Dec 2012 | B2 |
8364098 | Ridgers | Jan 2013 | B2 |
8368485 | Brown | Feb 2013 | B2 |
8385910 | Nazrul et al. | Feb 2013 | B2 |
8462031 | Belot et al. | Jun 2013 | B2 |
8542768 | Kim et al. | Sep 2013 | B2 |
8644776 | Nobbe et al. | Feb 2014 | B1 |
8649739 | Gorbachov | Feb 2014 | B2 |
8655441 | Fletcher et al. | Feb 2014 | B2 |
8676521 | Vennelakanti et al. | Mar 2014 | B2 |
9590572 | Rada et al. | Mar 2017 | B2 |
9755580 | Desclos | Sep 2017 | B2 |
20010037676 | Chang | Nov 2001 | A1 |
20020109607 | Cumeral et al. | Aug 2002 | A1 |
20040036554 | Veyres | Feb 2004 | A1 |
20040063410 | Pugel | Apr 2004 | A1 |
20040119099 | Tomita | Jun 2004 | A1 |
20040157550 | Nakagawa | Aug 2004 | A1 |
20040198288 | Sadowski | Oct 2004 | A1 |
20040229585 | Lu et al. | Nov 2004 | A1 |
20040240588 | Miller | Dec 2004 | A1 |
20050003785 | Jackson et al. | Jan 2005 | A1 |
20050009480 | Vakilian et al. | Jan 2005 | A1 |
20050069051 | Lourens | Mar 2005 | A1 |
20050270172 | Bailey et al. | Dec 2005 | A1 |
20060028297 | Kang et al. | Feb 2006 | A1 |
20060226897 | De Ruijter | Oct 2006 | A1 |
20070030099 | Carpentier | Feb 2007 | A1 |
20070066265 | May | Mar 2007 | A1 |
20070105521 | Ata | May 2007 | A1 |
20070139130 | Kim et al. | Jun 2007 | A1 |
20070207749 | Rozenblit et al. | Sep 2007 | A1 |
20080101185 | Rozenblit et al. | May 2008 | A1 |
20080176529 | Lau | Jul 2008 | A1 |
20080269841 | Grevious et al. | Oct 2008 | A1 |
20090079524 | Cyr et al. | Mar 2009 | A1 |
20090079607 | Denison et al. | Mar 2009 | A1 |
20090117867 | Ko | May 2009 | A1 |
20090147837 | Lau | Jun 2009 | A1 |
20090160578 | Achour | Jun 2009 | A1 |
20090322544 | McDowell | Dec 2009 | A1 |
20100080270 | Chen et al. | Apr 2010 | A1 |
20100109805 | Achour | May 2010 | A2 |
20100152644 | Pesach et al. | Jun 2010 | A1 |
20100225417 | Mistretta et al. | Sep 2010 | A1 |
20100237935 | Brown | Sep 2010 | A1 |
20100279635 | Ridgers | Nov 2010 | A1 |
20100308999 | Chornenky | Dec 2010 | A1 |
20100313958 | Patel et al. | Dec 2010 | A1 |
20110007844 | Park et al. | Jan 2011 | A1 |
20110018777 | Brown | Jan 2011 | A1 |
20110037516 | Nejati et al. | Feb 2011 | A1 |
20110050364 | Achour | Mar 2011 | A1 |
20110093220 | Yang et al. | Apr 2011 | A1 |
20110117834 | Martin | May 2011 | A1 |
20110143685 | Cebi | Jun 2011 | A1 |
20110212692 | Hahn | Sep 2011 | A1 |
20110234316 | Kim et al. | Sep 2011 | A1 |
20110241798 | Hong | Oct 2011 | A1 |
20110301882 | Andersen | Dec 2011 | A1 |
20120019336 | Khan et al. | Jan 2012 | A1 |
20120106560 | Gumaste | May 2012 | A1 |
20120112852 | Manssen et al. | May 2012 | A1 |
20120121030 | Luo et al. | May 2012 | A1 |
20120164644 | Neely et al. | Jun 2012 | A1 |
20120193017 | Martineau et al. | Jul 2012 | A1 |
20120280754 | Gorbachov | Nov 2012 | A1 |
20120314811 | Goldfarb | Dec 2012 | A1 |
20130029350 | Cooper et al. | Jan 2013 | A1 |
20130059548 | Umeda et al. | Mar 2013 | A1 |
20130113666 | Orsi et al. | May 2013 | A1 |
20130128934 | Kang et al. | May 2013 | A1 |
20130170588 | Park et al. | Jul 2013 | A1 |
20130222058 | Maniwa | Aug 2013 | A1 |
20130295863 | Shanan | Nov 2013 | A1 |
20140141738 | Janesch | May 2014 | A1 |
20140150554 | Rada et al. | Jun 2014 | A1 |
20140154991 | Brown et al. | Jun 2014 | A1 |
20140171002 | Park et al. | Jun 2014 | A1 |
20140266420 | Brown et al. | Sep 2014 | A1 |
20140266962 | Dupuy et al. | Sep 2014 | A1 |
20140269972 | Rada et al. | Sep 2014 | A1 |
20140273898 | Brown et al. | Sep 2014 | A1 |
20140287704 | Dupuy et al. | Sep 2014 | A1 |
20150070093 | Rada et al. | Mar 2015 | A1 |
20170187337 | Dupuy et al. | Jun 2017 | A1 |
20180026591 | Rada et al. | Jan 2018 | A1 |
20180205350 | Rada et al. | Jul 2018 | A1 |
20180205351 | Rada et al. | Jul 2018 | A1 |
Number | Date | Country |
---|---|---|
0283401 | Sep 1988 | EP |
1384281 | Jan 2004 | EP |
648920 | Jan 1951 | GB |
2354329 | Mar 2001 | GB |
56-138340 | Oct 1981 | JP |
56-138342 | Oct 1981 | JP |
60-249436 | Dec 1985 | JP |
H-08148949 | Jun 1996 | JP |
H-09-511877 | Nov 1997 | JP |
10-075273 | Mar 1998 | JP |
H10-290122 | Oct 1998 | JP |
2000-022450 | Jan 2000 | JP |
2009-055097 | Mar 2009 | JP |
2011-503950 | Jan 2011 | JP |
WO-9522197 | Aug 1995 | WO |
WO 2000035124 | Jun 2000 | WO |
WO 2002084782 | Oct 2002 | WO |
WO 2008018836 | Feb 2008 | WO |
WO 2008075066 | Jun 2008 | WO |
WO-2009056889 | May 2009 | WO |
WO 2012153147 | Nov 2012 | WO |
WO-2015038191 | Mar 2015 | WO |
Entry |
---|
European Patent Application No. 13860466.5; Extended Search Report; dated Jul. 27, 2016; 7 pages. |
European Patent Application No. 13859934.5; Extended Search Report; dated Jul. 27, 2016; 9 pages. |
U.S. Appl. No. 14/216,945, filed Mar. 17, 2014, Rada et al. |
Sanders B.J.; “Radical Combiner Runs Circles Around Hybrids,” MicroWaves; Nov. 1980; vol. 19, No. 12; p. 55-58. |
Caloz et al.;“Metamaterials for High-Frequency Electronics”; Proceedings of the IEEE; vol. 93; No. 10; Oct. 2005; p. 1 744-1752. |
Insam; “Designing Super-Regenerative Receivers”; Electronic World; Apr. 2002; 19 pages. |
International Patent Application No. PCT/US2014/029577; Int'l Preliminary Report on Patentability; dated Jun. 19, 2015; 17 pages. |
International Patent Application No. PCT/US2014/029832; Int'l Preliminary Report on Patentability; dated Mar. 11, 2015; 7 pages. |
European Patent Application No. 14764728.3; Extended Search Report; dated Mar. 3, 2017; 13 pages. |
European Patent Application No. 14844032.4; Extended Search Report; dated Apr. 5, 2017; 12 pages. |
International Search Report dated Jul. 29, 2014, for PCT Application No. PCT/US2014/029810, 2 pages. |
Written Opinion of the International Searching Authority dated Jul. 29, 2014, for PCT Application No. PCT/US2014/029810, 8 pages. |
Non-Final Office Action dated May 18, 2018 in U.S. Appl. No. 15/460,595, filed Mar. 16, 2017 by Rada et al. 15 pages. |
Non-Final Office Action dated Jul. 26, 2018 in U.S. Appl. No. 15/723,060, filed Oct. 2, 2017 by Rada et al. 8 pages. |
Number | Date | Country | |
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20160218683 A1 | Jul 2016 | US |
Number | Date | Country | |
---|---|---|---|
61877218 | Sep 2013 | US |
Number | Date | Country | |
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Parent | 14213529 | Mar 2014 | US |
Child | 15087720 | US |