CN104980383A - Transmitter local oscillator leakage reduction system - Google Patents
Transmitter local oscillator leakage reduction system Download PDFInfo
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- CN104980383A CN104980383A CN201510431589.5A CN201510431589A CN104980383A CN 104980383 A CN104980383 A CN 104980383A CN 201510431589 A CN201510431589 A CN 201510431589A CN 104980383 A CN104980383 A CN 104980383A
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Abstract
The invention provides a transmitter local oscillator leakage reduction system which comprises a current source module, a digital logic control module and a comparator. The comparator is used for collecting the DC offset signal outputted by a filter and outputting a feedback control signal according to the DC offset signal. The digital logic control module is used for correspondingly controlling the on and off of the first polarity switch sp and a second polarity switch sn according to the feedback control signal, using a binary successive one addition mode to control the on and off states of the switch S1 to the switch Sm of the current source module and locking the on and off states of the switch S1 to the switch Sm of the current source module until the jump of the feedback control signal is detected. The current source module carries out Dc compensation on the filter according to the current value generated in the on and off states of the current switch S1 to the switch Sm. According to the system, the DC offset signal of the transmitter can be automatically calibrated, and thus the local oscillator leakage is reduced.
Description
Technical field
The present invention relates to a kind of local oscillator leakage of transmitter and reduce system.
Background technology
Modern communication technology is maked rapid progress, and various wireless communication standard emerges in an endless stream.In transmitters, local oscillator leakage is one of key factor causing transmitter output signal degradation.
As shown in Figure 1, one of reason causing local oscillator leakage be due to frequency mixer in transmitter before the device mismatch that possesses of prime modular circuit itself cause DC maladjustment to cause, DC maladjustment is larger, then local oscillator leakage is larger; In order to reduce DC maladjustment, the size of general increased device is in transmitters to reduce the mismatch of device, but what bring while increased device size is but that the change of parasitic capacitance is large, this can extreme influence frequency mixer prime module as the stability of amplifier in the module such as digital to analog converter, filter and gain bandwidth product.
Summary of the invention
For the deficiencies in the prior art, the present invention is intended to provide a kind of local oscillator leakage of transmitter solved the problems of the technologies described above to reduce system.
For achieving the above object, the present invention adopts following technical scheme:
A kind of local oscillator leakage of transmitter reduces system, and it comprises current source module, Digital Logic control module and comparator;
Current source module comprise current value with two the current source I that increases progressively one by one of multiple to current source 2
mi, wherein, m is positive integer; Current source I is to current source 2
mthe equal ground connection in one end of I, one end of other end difference connecting valve S1 to switch S m; The other end of switch S 1 to switch S m all connects the first input end VIP of filter by the first polarity switch sp, also all by the second input of the filter of the second polarity switch sn contact resistance feedback-type;
End of oppisite phase and the in-phase end of comparator are connected the first output and second output of filter respectively; The DC maladjustment signal that this comparator exports for gathering filter, and export a feedback control signal according to DC maladjustment signal;
The input of Digital Logic control module connects comparator, and each output of digital logic module connects switch S 1 to the switch S m of current source module, the first polarity switch sp and the second polarity switch sn respectively;
This Digital Logic control module is used for controlling the first polarity switch sp of current source module and the keying of the second polarity switch sn according to feedback control signal correspondence, and adopt binary system successively to add open/close states that a mode controls switch S 1 to the switch S m of current source module, until feedback control signal generation saltus step detected, pin the open/close states of switch S 1 to the switch S m of current flow source module; Current source module carries out DC compensation with the current value produced under the open/close states of current switch S1 to switch S m to filter.
Preferably, when feedback control signal is low level signal, the first polarity switch sp that Digital Logic control module controls current source module closes and the second polarity switch sn conducting;
When feedback control signal is high level signal, the first polarity switch sp conducting and the second polarity switch sn of Digital Logic control module control current source module close;
When feedback control signal jumps to high level signal from low level signal, or when jumping to low level signal from high level signal, Digital Logic control module pins the open/close states of switch S 1 to the switch S m of current flow source module.
Beneficial effect of the present invention is at least as follows:
Digital Logic of the present invention controls the current polarity that mould exports according to the feedback control signal control current source module of comparator, and adopt binary system successively to add a mode to carry out scanning the compensation current finding current source module the most applicable filter, to make current source module provide suitable offset current when transmitter works, thus reduce local oscillator leakage.
Accompanying drawing explanation
Fig. 1 is the primary structure schematic diagram of existing transmitter.
Fig. 2 is the structural representation that local oscillator leakage of transmitter of the present invention reduces the better embodiment of system.
Embodiment
Below in conjunction with accompanying drawing and embodiment, the present invention is described further:
Refer to Fig. 2, the present invention relates to a kind of local oscillator leakage of transmitter and reduce system, its better embodiment comprises current source module 101, Digital Logic control module 102 and comparator 103;
Current source module 101 comprise current value with 2 the current source I that increases progressively one by one of multiple to current source 2
mi, wherein, m is positive integer.Current source I is to current source 2
mthe equal ground connection in one end of I, one end of other end difference connecting valve S1 to switch S m; The other end of switch S 1 to switch S m all connects the first input end VIP of filter by the first polarity switch sp, also all by the second input VIN of the filter of the second polarity switch sn contact resistance feedback-type;
End of oppisite phase and the in-phase end of comparator 103 are connected the first output VON and the second output VOP of filter respectively; The DC maladjustment signal that this comparator 103 exports for gathering filter, and export a feedback control signal according to DC maladjustment signal; During transmitter chip operation, base band is by digital to analog converter conveying direct current signal to filter, and the direct current signal that filter exports comprises the DC maladjustment information of digital to analog converter and filter.
The input of Digital Logic control module 102 connects comparator 103, and each output of digital logic module 102 connects switch S 1 to the switch S m of current source module 101, the first polarity switch sp and the second polarity switch sn respectively;
This Digital Logic control module 102 is for controlling the first polarity switch sp of current source module 101 and the keying of the second polarity switch sn according to feedback control signal correspondence, and adopt binary system successively to add open/close states that a mode controls switch S 1 to the switch S m of current source module 101, until feedback control signal generation saltus step detected, pin the open/close states of switch S 1 to the switch S m of current flow source module 101; Current source module 101 carries out DC compensation with the current value produced under the open/close states of current switch S1 to switch S m to filter.
Such as, current source module 101 comprises switch S 1 to switch S 4, then Digital Logic control module 102 adopts binary system successively to add a mode when controlling current source module 101, the control signal that Digital Logic control module 102 is sent to switch S 1 to switch S 4 in the t1 moment is 0001, 0010 is sent in the t2 moment, 0011 is sent in the t3 moment, by that analogy, successively add a mode by binary system and carry out scan control, to find the compensation current of the most applicable filter of current source module 101, when finding applicable compensation current (being determined by the open/close states of switch S 1 to switch S m), to saltus step be there is in the level signal that comparator exports, now, namely Digital Logic control module 102 pins the control signal of current switch S1 to switch S 4, so that when transmitter normally works, with this suitable compensation current, DC maladjustment compensation is carried out to transmitter, thus minimizing local oscillator leakage.
Here be pointed out that, when the digital to analog converter of existing transmitter and filter work, whether base band inputs useful signal and all can produce DC maladjustment signal, native system is selected when transmitter base band does not input useful signal, for the DC maladjustment that the device mismatch of transmitter own causes, search out the compensation current of this transmitter applicable with scan mode.So, transmitter is normally after startup work, namely can this compensation current compensating direct current misalignment signal, thus reduces local oscillator leakage to greatest extent, also can improve the stability of transmitter work simultaneously.
So, the present invention can the DC maladjustment that produces at prime module place of automatic calibration transmitter, and then reduces local oscillator leakage.
Wherein, the compensation current scope that current source module 101 produces is I ~ (2
2m-1) R4 in I, Fig. 2 is the feedback resistance of filter, and the differential voltage that this compensation current is finally produced at the first output VON of filter and the second output VOP by feedback resistance R4 is I*R4 ~ (2
2m-1) I*R4.
Preferably, when feedback control signal is low level signal, the first polarity switch sp that Digital Logic control module 102 controls current source module 101 closes and the second polarity switch sn conducting; When feedback control signal is high level signal, Digital Logic control module 102 controls the first polarity switch sp conducting of current source module 101 and the second polarity switch sn closes.
When feedback control signal jumps to high level signal from low level signal, or when jumping to low level signal from high level signal, Digital Logic control module 102 pins the open/close states of switch S 1 to the switch S m of current flow source module.
For a person skilled in the art, according to technical scheme described above and design, other various corresponding change and distortion can be made, and all these change and distortion all should belong within the protection range of the claims in the present invention.
Claims (2)
1. local oscillator leakage of transmitter reduces a system, it is characterized in that: it comprises current source module, Digital Logic control module and comparator;
Current source module comprise current value with two the current source I that increases progressively one by one of multiple to current source 2
mi, wherein, m is positive integer; Current source I is to current source 2
mthe equal ground connection in one end of I, one end of other end difference connecting valve S1 to switch S m; The other end of switch S 1 to switch S m all connects the first input end VIP of filter by the first polarity switch sp, also all by the second input of the filter of the second polarity switch sn contact resistance feedback-type;
End of oppisite phase and the in-phase end of comparator are connected the first output and second output of filter respectively; The DC maladjustment signal that this comparator exports for gathering filter, and export a feedback control signal according to DC maladjustment signal;
The input of Digital Logic control module connects comparator, and each output of digital logic module connects switch S 1 to the switch S m of current source module, the first polarity switch sp and the second polarity switch sn respectively;
This Digital Logic control module is used for controlling the first polarity switch sp of current source module and the keying of the second polarity switch sn according to feedback control signal correspondence, and adopt binary system successively to add open/close states that a mode controls switch S 1 to the switch S m of current source module, until feedback control signal generation saltus step detected, pin the open/close states of switch S 1 to the switch S m of current flow source module; Current source module carries out DC compensation with the current value produced under the open/close states of current switch S1 to switch S m to filter.
2. local oscillator leakage of transmitter as claimed in claim 1 reduces system, it is characterized in that: when feedback control signal is low level signal, and the first polarity switch sp that Digital Logic control module controls current source module closes and the second polarity switch sn conducting;
When feedback control signal is high level signal, the first polarity switch sp conducting and the second polarity switch sn of Digital Logic control module control current source module close;
When feedback control signal jumps to high level signal from low level signal, or when jumping to low level signal from high level signal, Digital Logic control module pins the open/close states of switch S 1 to the switch S m of current flow source module.
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| CN201510431589.5A CN104980383B (en) | 2015-07-21 | 2015-07-21 | Local oscillator leakage of transmitter reduces system |
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| CN201510431589.5A CN104980383B (en) | 2015-07-21 | 2015-07-21 | Local oscillator leakage of transmitter reduces system |
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| CN104980383B CN104980383B (en) | 2018-04-17 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106610685A (en) * | 2015-10-26 | 2017-05-03 | 北京北方微电子基地设备工艺研究中心有限责任公司 | Method and device for adjusting output current of power source |
| US10361745B2 (en) | 2017-06-28 | 2019-07-23 | Qualcomm Incorporated | Systems and methods for reducing transmit and receive power via a T/R switch |
| CN110572225A (en) * | 2019-07-18 | 2019-12-13 | 广州润芯信息技术有限公司 | Receiver direct current offset monitoring system, method, electronic device and storage medium |
| CN115529023A (en) * | 2022-11-23 | 2022-12-27 | 南京邮电大学 | Filter circuit with DC offset elimination |
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| US20070042728A1 (en) * | 2005-08-16 | 2007-02-22 | Broadcom Corporation | Transmitter having DC offset cancellation |
| CN101079645A (en) * | 2006-05-25 | 2007-11-28 | 北京六合万通微电子技术有限公司 | Device for eliminating local vibration leakage in the wireless communication transmitter |
| CN101155160A (en) * | 2006-09-29 | 2008-04-02 | 锐迪科微电子（上海）有限公司 | Up-conversion mixer |
| CN101162910A (en) * | 2006-10-10 | 2008-04-16 | 北京六合万通微电子技术有限公司 | Local oscillator leakage automatic eliminator |
| CN103701420A (en) * | 2013-11-27 | 2014-04-02 | 广州润芯信息技术有限公司 | Transmitter gain distribution method and circuit |
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2015
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070042728A1 (en) * | 2005-08-16 | 2007-02-22 | Broadcom Corporation | Transmitter having DC offset cancellation |
| CN101079645A (en) * | 2006-05-25 | 2007-11-28 | 北京六合万通微电子技术有限公司 | Device for eliminating local vibration leakage in the wireless communication transmitter |
| CN101155160A (en) * | 2006-09-29 | 2008-04-02 | 锐迪科微电子（上海）有限公司 | Up-conversion mixer |
| CN101162910A (en) * | 2006-10-10 | 2008-04-16 | 北京六合万通微电子技术有限公司 | Local oscillator leakage automatic eliminator |
| CN103701420A (en) * | 2013-11-27 | 2014-04-02 | 广州润芯信息技术有限公司 | Transmitter gain distribution method and circuit |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106610685A (en) * | 2015-10-26 | 2017-05-03 | 北京北方微电子基地设备工艺研究中心有限责任公司 | Method and device for adjusting output current of power source |
| US10361745B2 (en) | 2017-06-28 | 2019-07-23 | Qualcomm Incorporated | Systems and methods for reducing transmit and receive power via a T/R switch |
| CN110572225A (en) * | 2019-07-18 | 2019-12-13 | 广州润芯信息技术有限公司 | Receiver direct current offset monitoring system, method, electronic device and storage medium |
| CN110572225B (en) * | 2019-07-18 | 2022-04-15 | 广州润芯信息技术有限公司 | Receiver direct current offset monitoring system, method, electronic device and storage medium |
| CN115529023A (en) * | 2022-11-23 | 2022-12-27 | 南京邮电大学 | Filter circuit with DC offset elimination |
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| CN104980383B (en) | 2018-04-17 |
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Effective date of registration: 20151223 Address after: Nanxiang Road two Whampoa Science City District of Guangzhou City, Guangdong province 510000 No. 23 6 floor B605Bx Applicant after: Guangzhou Runxin Information Technology Co., Ltd. Applicant after: Guangzhou Haige Communications Group Address before: 8, 510000 building, east block, A building, 11 Cai Cai road, Guangdong, Guangzhou Applicant before: Guangzhou Runxin Information Technology Co., Ltd. |
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Effective date of registration: 20170713 Address after: High tech Industrial Development Zone, Guangzhou City, Guangdong province 510663 Science City sea Yun Lu No. 88 Applicant after: Guangzhou Haige Communications Group Address before: Nanxiang Road two Whampoa Science City District of Guangzhou City, Guangdong province 510000 No. 23 6 floor B605Bx Applicant before: Guangzhou Runxin Information Technology Co., Ltd. Applicant before: Guangzhou Haige Communications Group |
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Effective date of registration: 20190312 Address after: 510000 B605B, 6th floor, 23 Nanxiang Second Road, Science City, Huangpu District, Guangzhou City, Guangdong Province Co-patentee after: Guangzhou Haige Communications Group Patentee after: Guangzhou Runxin Information Technology Co., Ltd. Address before: 510663 No. 88 Haiyun Road, Science City, Guangzhou High-tech Industrial Development Zone, Guangdong Province Patentee before: Guangzhou Haige Communications Group |
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