CN108418583B - Broadband fine stepping frequency agility frequency synthesis device and method based on cascade frequency mixing - Google Patents
Broadband fine stepping frequency agility frequency synthesis device and method based on cascade frequency mixing Download PDFInfo
- Publication number
- CN108418583B CN108418583B CN201810228690.4A CN201810228690A CN108418583B CN 108418583 B CN108418583 B CN 108418583B CN 201810228690 A CN201810228690 A CN 201810228690A CN 108418583 B CN108418583 B CN 108418583B
- Authority
- CN
- China
- Prior art keywords
- frequency
- output
- stage
- power divider
- mixer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 7
- 238000000034 method Methods 0.000 title claims abstract description 7
- 238000003786 synthesis reaction Methods 0.000 title claims abstract description 7
- 230000010355 oscillation Effects 0.000 claims description 9
- 230000002194 synthesizing effect Effects 0.000 claims 2
- 238000001308 synthesis method Methods 0.000 abstract description 7
- 238000010586 diagram Methods 0.000 description 2
- 238000003384 imaging method Methods 0.000 description 2
- 230000008054 signal transmission Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
- H03L7/00—Automatic control of frequency or phase; Synchronisation
- H03L7/06—Automatic control of frequency or phase; Synchronisation using a reference signal applied to a frequency- or phase-locked loop
- H03L7/16—Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop
Landscapes
- Radar Systems Or Details Thereof (AREA)
- Superheterodyne Receivers (AREA)
Abstract
The invention relates to a broadband fine stepping frequency agility synthesis device and a method based on cascade frequency mixing. In the level of the existing device, through proper type selection, the frequency synthesis method has the characteristics of wide band, fine stepping, frequency agility, low phase noise, low stray and miniaturization.
Description
Technical Field
The invention belongs to the technical field of microwaves, relates to a high-performance design of a microwave frequency source, and particularly relates to a broadband fine-stepping frequency agility frequency synthesis device and method based on cascade frequency mixing.
Background
The microwave frequency source is a key component in a microwave circuit, and particularly has harsh performance indexes in application scenes such as radar, interference countermeasure, microwave imaging and the like. The existing frequency synthesis methods are more traditional and are difficult to meet the requirements of broadband, fine stepping, frequency agility, low phase noise, low stray and miniaturization. The invention provides a frequency synthesis method based on cascade frequency mixing, which has the characteristics of broadband, fine stepping, frequency agility, low phase noise, low stray and miniaturization through proper type selection under the level of the conventional device.
Disclosure of Invention
Technical problem to be solved
In the application scenarios of radar, interference countermeasure, microwave imaging, etc., the requirements for the indexes of frequency sources are more demanding. The existing frequency synthesis method is difficult to meet the requirements of broadband, low phase noise, fine stepping, frequency agility, low stray and miniaturization. The invention provides a novel microwave frequency synthesis device and a method, and the method can simultaneously meet the high index and miniaturization requirements of a microwave frequency source based on the level of the current device.
Technical scheme
A broadband fine stepping frequency agility frequency synthesis device based on cascade frequency mixing comprises a first local vibration source, a DDS (direct digital synthesizer), a second local vibration source, an M-level frequency mixer, an M-1-level two-path power divider, an M-1-path power divider and a single-pole M throw switch, wherein M is a positive integer larger than 1; the first local vibration source generates F1、F2、...、FNDot frequency of (1), wherein F2-F1＝F3-F2＝···＝FN-FN-1＝BW0N is a positive integer; DDS generation frequency range of Fa～FbHaving a bandwidth of BW0The frequency step of the fine step intermediate frequency signal can reach 0.1 Hz; the second local oscillator generates a frequency of NxBW0The single-point frequency signal of (1); the first local vibration source is connected with an LO port of the first-stage mixer, the DDS is connected with an IF port of the first-stage mixer, and the output of the first-stage mixer is connected with the first-stage two-path power divider; the second local oscillation source divides the M-1 path of second local oscillation signals through the M-1 path of power divider, and the second local oscillation signals divided by each path of power are connected with an IF port of a mixer; after the first-stage two-path power divider is divided into two paths, one path is mixed with the M-1 path divided by the second local vibration source power and then input into the second-stage two pathsAnd the other path of the power divider is directly input into the single-pole M-throw switch, the connection relation from the second-stage power divider to the (M-1) th-stage power divider is the same as that of the first-stage power divider, and the output of the M-th-stage frequency mixer is connected to the single-pole M-throw switch.
When the first local oscillator provides a dot frequency of F1, the sum frequency of the output of the mixer is taken, and the output frequency is F1+Fa～F1+FbBandwidth is BW0(ii) a When the first local vibration source provides F2Taking the sum frequency of the output of the mixer when the dot frequency is equal to F2+Fa～F2+FbBandwidth is BW0(ii) a By analogy, when the first local vibration source provides FNTaking the sum frequency of the output of the mixer when the dot frequency is equal to FN+Fa～FN+FbBandwidth is BW0(ii) a The frequency range of the first stage mixing output is F1+Fa～FN+FbBandwidth of NxBW0(ii) a Let FA＝F1+Fa，FB＝FN+Fb，BWN＝N×BW0(ii) a The signal enters the two-way power divider and then enters the single-pole M-throw switch, and when the way is gated, F can be finally outputA～FBFrequency signal with bandwidth BWN；
FA～FBThe signal is output from the two-way power divider to the second-stage mixer and is mixed with the second local oscillator point frequency BWNThe signals are mixed, the difference frequency of the mixed signals is FA-BWN～FB-BWNSum frequency signal of FA+BMN～FB+BWNBoth sum and difference bandwidths being BWN(ii) a The signal enters the two-way power divider and then enters the single-pole M-throw switch, and when the way is gated, F can be finally outputA-BWN～FB-BWNAnd FA+BWN～FB+BWN(ii) a The frequency band of the output signal after the first-stage frequency mixing is FA～FBThe second path and the first path together can output FA-BWN～FB+BWN(ii) a By analogy with thatWhen the cascade mixing link reaches M stages, the frequency range which can be finally output from the single-pole M-throw switch is FA-(M-1)×BWN～FB+(M-1)×BWN(ii) a When F is presentA-(M-1)×BWNWhen the frequency is less than or equal to 0, it is necessary to stop taking the difference frequency and only take the sum frequency.
Advantageous effects
The frequency synthesis method is based on cascade mixing and can realize the advantages of broadband, fine stepping, frequency agility, low phase noise, low stray, miniaturization and the like.
Drawings
FIG. 1 is a block diagram of a frequency synthesis method based on cascade mixing
FIG. 2 shows a 3-8 GHz frequency source scheme based on cascade frequency mixing
Detailed Description
The invention will now be further described with reference to the following examples and drawings:
the signal flow chart of the frequency synthesis method based on cascade mixing is shown in the figure I. Wherein 1 is the first local vibration source, and the signal has the characteristics of low phase noise, coarse stepping and wide band and can provide F1,F2...FN(N is a positive integer) dot frequency, where F2-F1＝F3-F2＝···＝FN-FN-1＝BW0(ii) a 3 is a DDS-based fine step intermediate frequency signal, providing a frequency range F of the signala～FbBandwidth is BW0The frequency step can reach 0.1 Hz; 2 is a second local oscillator, which is a single-point frequency signal with a frequency of NxBW0(ii) a 4 and the same graphic symbol as 4 are mixers; 5 and the same graphic symbol as 5 are two-way power dividers; the 6 is an M-1(M is a positive integer more than 1) path power divider; and 7 is a single-pole M-throw switch. The first local oscillator 1 is input to the LO port of the mixer, and the second local oscillator 2 and the intermediate frequency signal 3 are input to the IF port of the mixer. And the second local oscillation source 2 divides the M-1 paths of second local oscillation signals through the M-1 paths of power dividers. The arrow direction indicates the signal transmission direction.
When the first local vibration source provides F1At a point frequency of (1), get and mixThe frequency of the output sum frequency of the frequency converter is F1+Fa～F1+FbBandwidth is BW0(ii) a When the first local vibration source provides F2Taking the sum frequency of the output of the mixer when the dot frequency is equal to F2+Fa～F2+FbBandwidth is BW0(ii) a By analogy, when the first local vibration source provides FNTaking the sum frequency of the output of the mixer when the dot frequency is equal to FN+Fa～FN+FbBandwidth is BW0. Due to F1,F2...FNBW difference of frequency points0It is readily apparent that the frequency range of the first stage mixing output is F1+Fa～FN+FbBandwidth of NxBW0. For convenience of representation, set FA＝F1+Fa，FB＝FN+Fb，BWN＝N×BW0. The signal enters the two-way power divider and then enters the single-pole M-throw switch, and when the way is gated, F can be finally outputA～FBFrequency signal with bandwidth BWN。
FA～FBThe signal is output from the two-way power divider to the second-stage mixer (M is 2 at this time), and then is mixed with the second local oscillator point frequency BWNThe signals are mixed, the difference frequency of the mixed signals is FA-BWN～FB-BWNSum frequency signal of FA+BMN～FB+BWNIt is not difficult to find that both sum and difference bandwidths are BWN. The signal enters the two-way power divider and then enters the single-pole M-throw switch, and when the way is gated, F can be finally outputA-BWN～FB-BWNAnd FA+BWN～FB+BWN. The frequency band of the output signal after the first-stage frequency mixing is FA～FBThe second path and the first path together can output FA-BWN～FB+BWN。
By analogy, when the cascade mixing link reaches M stages, the frequency range of the output frequency from the single-pole M-throw switch is FA-(M-1)×BWN～FB+(M-1)×BWN。
It should be noted that when FA-(M-1)×BWNWhen the frequency is less than or equal to 0, it is necessary to stop taking the difference frequency and only take the sum frequency, because the frequency cannot be a negative number.
The specific frequency source scheme is shown in fig. two, where N is 5, M is 3, BW0200 MHz. 1 is a first local vibration source and is a point frequency of 4.7GHz and 4.9GHz.. 5.5 GHz; 2 is a second local vibration source and is at 1GHz point frequency; 3 is a fine step intermediate frequency signal based on DDS, the frequency band is 300 MHz-500 MHz, and the step is 0.1 Hz; 4 and the same graphic symbol as 4 are mixers; 5 and the same graphic symbol as 5 are two-way power dividers; 6 is a 2-path power divider; and 7 is a single-pole 3-throw switch. The first local oscillator 1 is input to the LO port of the mixer, and the second local oscillator 2 and the intermediate frequency signal 3 are input to the IF port of the mixer.
First-stage mixing: and after the intermediate frequency signal and the first local oscillation signal are mixed, the sum frequency of the output of the mixer is taken, and the frequency range of 5 GHz-6 GHz can be output. And (3) second-stage frequency mixing: the first stage output signal and the second local oscillator are mixed, the difference frequency signal is 4 GHz-5 GHz, the sum frequency signal is 6 GHz-7 GHz, and the first stage output signal and the second local oscillator are combined to output 4 GHz-7 GHz signals. Third stage mixing: the second-stage output signal and a second local oscillator are mixed, the difference frequency signal is 3 GHz-4 GHz, the sum frequency signal is 7 GHz-8 GHz, the difference frequency signal and the first two-stage signal are combined and then the 3 GHz-8 GHz signal can be output, and a signal flow diagram is shown in the second figure in detail.
Claims (2)
1. A broadband fine stepping frequency agility frequency synthesis device based on cascade frequency mixing is characterized by comprising a first local vibration source (1), a DDS (3), a second local vibration source (2), an M-level frequency mixer (4), an M-1-level two-path power divider (5), an M-1-path power divider (6) and a single-pole M throw switch (7), wherein M is a positive integer greater than 1; the first local vibration source (1) generates F1、F2、...、FNDot frequency of (1), wherein F2-F1＝F3-F2＝···＝FN-FN-1＝BW0N is a positive integer; DDS (3) generating frequency range of Fa～FbHaving a bandwidth of BW0The frequency step of the fine step intermediate frequency signal can reach 0.1 Hz; the second local vibration source (3) generates a frequency of NxBW0Is not only a sheetA dot frequency signal; the first local vibration source (1) is connected with an LO port of the first-stage mixer, the DDS (3) is connected with an IF port of the first-stage mixer, and the output of the first-stage mixer is connected with the first-stage two-way power divider; the second local oscillation source (2) divides the M-1 path of second local oscillation signals through the M-1 path of power divider, and the second local oscillation signals divided by each path of power are connected with an IF port of a mixer; after the first-stage two-way power divider is divided into two paths, one path is mixed with the M-1 path of the power division of the second local vibration source (2) and then input into the second-stage two-way power divider, the other path is directly input into the single-pole M-throw switch (7), the connection relation from the second-stage two-way power divider to the M-1 stage two-way power divider is the same as that of the first-stage two-way power divider, and the output of the M-stage mixer is connected to the single-pole M-throw switch (7).
2. The method for synthesizing a wideband fine step-by-step agile frequency by the synthesizing device according to claim 1, wherein: when the first local oscillator (1) provides the dot frequency of F1, the sum frequency of the output of the mixer is taken, and the output frequency is F1+Fa～F1+FbBandwidth is BW0(ii) a When the first local vibration source provides F2Taking the sum frequency of the output of the mixer when the dot frequency is equal to F2+Fa～F2+FbBandwidth is BW0(ii) a By analogy, when the first local vibration source provides FNTaking the sum frequency of the output of the mixer when the dot frequency is equal to FN+Fa～FN+FbBandwidth is BW0(ii) a The frequency range of the first stage mixing output is F1+Fa～FN+FbBandwidth of NxBW0(ii) a Let FA＝F1+Fa，FB＝FN+Fb，BWN＝N×BW0(ii) a The signal output by the first-stage mixing enters the two-way power divider and then enters the single-pole M-throw switch, and when one way of the single-pole M-throw switch is switched on, F can be finally outputA～FBFrequency signal with bandwidth BWN；
FA～FBThe signal is output from the two-way power divider to the second-stage mixer and is mixed with the second local oscillator point frequency BWNThe signals are mixed, the difference frequency of the mixed signals isFA-BWN～FB-BWNSum frequency signal of FA+BMN～FB+BWNBoth sum and difference bandwidths being BWN(ii) a The signal output by the second-stage mixing enters the two-way power divider and then enters the single-pole M-throw switch, and when one way of the single-pole M-throw switch is switched on, F can be finally outputA-BWN～FB-BWNAnd FA+BWN～FB+BWN(ii) a The frequency band of the output signal after the first-stage frequency mixing is FA～FBThe second path and the first path together can output FA-BWN～FB+BWN(ii) a By analogy, when the cascade mixing link reaches M stages, the frequency range of the output frequency from the single-pole M-throw switch is FA-(M-1)×BWN～FB+(M-1)×BWN(ii) a When F is presentA-(M-1)×BWNWhen the frequency is less than or equal to 0, it is necessary to stop taking the difference frequency and only take the sum frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810228690.4A CN108418583B (en) | 2018-03-20 | 2018-03-20 | Broadband fine stepping frequency agility frequency synthesis device and method based on cascade frequency mixing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810228690.4A CN108418583B (en) | 2018-03-20 | 2018-03-20 | Broadband fine stepping frequency agility frequency synthesis device and method based on cascade frequency mixing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108418583A CN108418583A (en) | 2018-08-17 |
| CN108418583B true CN108418583B (en) | 2021-07-16 |
Family
ID=63133008
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810228690.4A Active CN108418583B (en) | 2018-03-20 | 2018-03-20 | Broadband fine stepping frequency agility frequency synthesis device and method based on cascade frequency mixing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108418583B (en) |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201197142Y (en) * | 2008-04-30 | 2009-02-18 | 南京肯立科技有限责任公司 | Satellite beacon receiver |
| CN101771382A (en) * | 2009-12-18 | 2010-07-07 | 武汉虹信通信技术有限责任公司 | Method and device for realizing frequency fine tuning by utilizing direct digital synthesis technology |
| CN202679345U (en) * | 2012-06-09 | 2013-01-16 | 成都西科微波通讯有限公司 | Ku-band ultra-low phase noise frequency source component |
| US8373463B1 (en) * | 2011-09-23 | 2013-02-12 | Phase Matrix, Inc. | Low phase-noise PLL synthesizer with frequency accuracy indicator |
| CN202856715U (en) * | 2012-11-01 | 2013-04-03 | 南京国睿安泰信科技股份有限公司 | System for realizing spectrum analyzer down-conversion with broadband local oscillators and high-frequency phase demodulation |
| CN103684443A (en) * | 2013-12-18 | 2014-03-26 | 无锡市雷华科技有限公司 | Method and device for compounding high-speed frequency agility markers |
| CN203574618U (en) * | 2013-11-06 | 2014-04-30 | 安徽白鹭电子科技有限公司 | Radio frequency signal source based on broadband frequency synthesizer ADF4351 |
| CN103888134A (en) * | 2014-04-09 | 2014-06-25 | 四川九洲电器集团有限责任公司 | Frequency synthesizer capable of achieving low phase noise, low stray and quick change |
| US8816777B2 (en) * | 2011-09-20 | 2014-08-26 | Tomany Szilagyi | Microwave synthesizer |
| CN204180053U (en) * | 2014-10-29 | 2015-02-25 | 石家庄东泰尔通信技术有限公司 | A kind of Low phase noise little stepping local oscillator module |
| CN104579339A (en) * | 2014-12-08 | 2015-04-29 | 西安电子工程研究所 | Low spurious signal source generating method and device for improving frequency stability |
| CN105245224A (en) * | 2015-11-05 | 2016-01-13 | 中国电子科技集团公司第四十一研究所 | Low-phase noise microwave local oscillation generating device and method |
| CN105553469A (en) * | 2015-12-11 | 2016-05-04 | 北京无线电计量测试研究所 | Low-phase noise frequency source |
| US9628066B1 (en) * | 2015-09-19 | 2017-04-18 | Oleksandr Chenakin | Fast switching, low phase noise frequency synthesizer |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2421154B1 (en) * | 2010-08-22 | 2014-07-02 | KROHNE Messtechnik GmbH | Switch assembly for generating high frequency output signals comprising a broadband frequency ramp |
| JP6627489B2 (en) * | 2015-12-21 | 2020-01-08 | セイコーエプソン株式会社 | Timing signal generator and electronic equipment |
-
2018
- 2018-03-20 CN CN201810228690.4A patent/CN108418583B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201197142Y (en) * | 2008-04-30 | 2009-02-18 | 南京肯立科技有限责任公司 | Satellite beacon receiver |
| CN101771382A (en) * | 2009-12-18 | 2010-07-07 | 武汉虹信通信技术有限责任公司 | Method and device for realizing frequency fine tuning by utilizing direct digital synthesis technology |
| US8816777B2 (en) * | 2011-09-20 | 2014-08-26 | Tomany Szilagyi | Microwave synthesizer |
| US8373463B1 (en) * | 2011-09-23 | 2013-02-12 | Phase Matrix, Inc. | Low phase-noise PLL synthesizer with frequency accuracy indicator |
| CN202679345U (en) * | 2012-06-09 | 2013-01-16 | 成都西科微波通讯有限公司 | Ku-band ultra-low phase noise frequency source component |
| CN202856715U (en) * | 2012-11-01 | 2013-04-03 | 南京国睿安泰信科技股份有限公司 | System for realizing spectrum analyzer down-conversion with broadband local oscillators and high-frequency phase demodulation |
| CN203574618U (en) * | 2013-11-06 | 2014-04-30 | 安徽白鹭电子科技有限公司 | Radio frequency signal source based on broadband frequency synthesizer ADF4351 |
| CN103684443A (en) * | 2013-12-18 | 2014-03-26 | 无锡市雷华科技有限公司 | Method and device for compounding high-speed frequency agility markers |
| CN103888134A (en) * | 2014-04-09 | 2014-06-25 | 四川九洲电器集团有限责任公司 | Frequency synthesizer capable of achieving low phase noise, low stray and quick change |
| CN204180053U (en) * | 2014-10-29 | 2015-02-25 | 石家庄东泰尔通信技术有限公司 | A kind of Low phase noise little stepping local oscillator module |
| CN104579339A (en) * | 2014-12-08 | 2015-04-29 | 西安电子工程研究所 | Low spurious signal source generating method and device for improving frequency stability |
| US9628066B1 (en) * | 2015-09-19 | 2017-04-18 | Oleksandr Chenakin | Fast switching, low phase noise frequency synthesizer |
| CN105245224A (en) * | 2015-11-05 | 2016-01-13 | 中国电子科技集团公司第四十一研究所 | Low-phase noise microwave local oscillation generating device and method |
| CN105553469A (en) * | 2015-12-11 | 2016-05-04 | 北京无线电计量测试研究所 | Low-phase noise frequency source |
Non-Patent Citations (2)
| Title |
|---|
| S波段GaN微波功率器件的研制;周泽伦 等;《电子器件》;20171220;第40卷(第1期);27-32 * |
| 高频谱纯度小步进频率合成器的设计与实现;蒋涛 等;《压电与声光》;20160415;第38卷(第2期);189-191 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108418583A (en) | 2018-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114070302B (en) | Broadband fine stepping frequency synthesis circuit and method | |
| CA2852383C (en) | Electronically tunable filter | |
| CN113225022B (en) | Ultra-wideband up-converter | |
| CN114070307B (en) | Broadband fast switching frequency synthesis circuit | |
| JP2012120178A (en) | Frequency synthesizer and frequency synthesizing method | |
| CN114389636A (en) | Multi-band high-performance signal processing platform | |
| CN110289858B (en) | Broadband fine stepping agile frequency conversion combination system | |
| CN112187259A (en) | Broadband agile frequency source | |
| CN108418583B (en) | Broadband fine stepping frequency agility frequency synthesis device and method based on cascade frequency mixing | |
| CN107196653B (en) | Broadband low-phase noise frequency synthesizer | |
| CN113794473A (en) | Universal frequency synthesizer and synthesis method | |
| CN108344977A (en) | Frequency stepping radar signal source system | |
| CN106888015B (en) | Broadband frequency agility millimeter wave frequency synthesizer | |
| KR20220101139A (en) | How to improve clock frequency coverage | |
| CN115208384B (en) | Low-spurious DDS (direct digital synthesizer) spread spectrum device and method | |
| CN115395950B (en) | Frequency synthesizer | |
| CN102355257B (en) | Digital signal generator | |
| CN114884468B (en) | Millimeter wave fast broadband frequency synthesis circuit and implementation method thereof | |
| CN202679314U (en) | X wave band lower clutter broadband up-converter | |
| CN111711447B (en) | Prescaler and frequency divider | |
| CN211296711U (en) | Ku waveband FMCW excitation source link structure based on phase-locked mode | |
| US7853419B2 (en) | Signal processing circuit and method for processing an HF input signal | |
| CN220586273U (en) | Agile frequency component system for scattering communication | |
| CN110995255A (en) | Broadband low-phase-noise phase-locked loop with quick locking function | |
| US20040178855A1 (en) | Technique for generating carrier frequencies with fast hopping capability |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |