zjwzcc 发表于 2011-10-14 15:25:01

自己做的gps定位板搜星信号很差很慢,请教

自己用gs-89 gps模块做的一个gps定位板子,板子上还附带有gprs模块,支持gps定位和gprs数据传输

现在发现gps模块搜星能力很差,板子是放在窗口的,天线用的是无源陶瓷天线(考虑到总体积尽量要求小,因此不选用室外gps天线)

现在测试发现往往开机后10-15分钟后,才能搜到4颗以上卫星。搜索能力极差,请问大家这个是不是天线部分没做好的原因还是??


http://cache.amobbs.com/bbs_upload782111/files_46/ourdev_684882Z8O6B7.jpg
gps内置无源陶瓷天线 (原文件名:IMAG0083.jpg)

d_xin 发表于 2011-10-14 15:33:16

布局的问题吧,天线放SIM卡边上。。。。。。

俺的做法是所有东西离天线有多远扔多远。

实在扔不了远的要做好抗干扰

zjwzcc 发表于 2011-10-14 15:35:32

回复【楼主位】zjwzcc
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附上当前从gps模块串口截得的数据和信号图


http://cache.amobbs.com/bbs_upload782111/files_46/ourdev_684884UHCRG4.jpg
gps软件截取数据 (原文件名:jwd.jpg)


$GPGGA,073318.407,3020.7285,N,12006.1696,E,2,03,5.9,-7.0,M,7.0,M,2.3,0000*6B
$GPGSA,A,2,28,10,13,,,,,,,,,,6.0,5.9,1.0*31
$GPGSV,3,1,10,10,51,200,34,28,36,182,33,13,18,116,32,17,70,044,*73
$GPGSV,3,2,10,04,56,308,,02,21,271,,20,21,043,,23,20,087,*7A
$GPGSV,3,3,10,12,04,324,,42,48,144,30*72
$GPRMC,073318.407,A,3020.7285,N,12006.1696,E,0.00,173.07,141011,,,D*64
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073319.407,3020.7286,N,12006.1696,E,2,03,5.9,-7.0,M,7.0,M,2.3,0000*69
$GPRMC,073319.407,A,3020.7286,N,12006.1696,E,0.00,173.07,141011,,,D*66
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073320.407,3020.7281,N,12006.1699,E,2,03,5.9,-7.0,M,7.0,M,2.3,0000*6B
$GPRMC,073320.407,A,3020.7281,N,12006.1699,E,0.00,173.07,141011,,,D*64
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073321.407,3020.7281,N,12006.1699,E,2,03,5.9,-7.0,M,7.0,M,1.3,0000*69
$GPRMC,073321.407,A,3020.7281,N,12006.1699,E,0.00,173.07,141011,,,D*65
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073322.407,3020.7280,N,12006.1700,E,2,03,5.9,-7.0,M,7.0,M,2.3,0000*69
$GPRMC,073322.407,A,3020.7280,N,12006.1700,E,0.00,173.07,141011,,,D*66
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073323.407,3020.7281,N,12006.1700,E,2,03,5.9,-7.0,M,7.0,M,3.3,0000*68
$GPGSA,A,2,28,10,13,,,,,,,,,,5.9,5.9,1.0*3B
$GPGSV,3,1,10,10,51,200,34,28,36,182,33,13,18,116,32,17,70,044,*73
$GPGSV,3,2,10,04,56,308,,02,21,271,,20,21,043,,23,20,087,*7A
$GPGSV,3,3,10,12,04,324,,42,48,144,28*7B
$GPRMC,073323.407,A,3020.7281,N,12006.1700,E,0.00,173.07,141011,,,D*66
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073324.407,3020.7280,N,12006.1700,E,2,03,5.9,-7.0,M,7.0,M,4.3,0000*69
$GPRMC,073324.407,A,3020.7280,N,12006.1700,E,0.00,173.07,141011,,,D*60
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073325.407,3020.7276,N,12006.1701,E,2,03,5.9,-7.0,M,7.0,M,2.3,0000*66
$GPRMC,073325.407,A,3020.7276,N,12006.1701,E,0.00,173.07,141011,,,D*69
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073326.407,3020.7281,N,12006.1696,E,2,03,5.8,-7.0,M,7.0,M,2.3,0000*63
$GPRMC,073326.407,A,3020.7281,N,12006.1696,E,0.00,173.07,141011,,,D*6D
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073327.407,3020.7281,N,12006.1696,E,2,03,5.8,-7.0,M,7.0,M,2.3,0000*62
$GPRMC,073327.407,A,3020.7281,N,12006.1696,E,0.00,173.07,141011,,,D*6C
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073328.407,3020.7281,N,12006.1696,E,2,03,5.8,-7.0,M,7.0,M,3.3,0000*6C
$GPGSA,A,2,28,10,13,,,,,,,,,,5.9,5.8,1.0*3A
$GPGSV,3,1,10,10,51,200,34,28,36,182,33,13,18,116,32,17,70,044,*73
$GPGSV,3,2,10,04,56,308,,02,21,271,,20,21,043,,23,20,087,*7A
$GPGSV,3,3,10,12,04,324,,42,48,144,29*7A
$GPRMC,073328.407,A,3020.7281,N,12006.1696,E,0.00,173.07,141011,,,D*63
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073329.407,3020.7281,N,12006.1695,E,2,03,5.8,-7.0,M,7.0,M,4.3,0000*69
$GPRMC,073329.407,A,3020.7281,N,12006.1695,E,0.00,173.07,141011,,,D*61
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073330.407,3020.7281,N,12006.1695,E,2,03,5.8,-7.0,M,7.0,M,5.3,0000*60
$GPRMC,073330.407,A,3020.7281,N,12006.1695,E,0.00,173.07,141011,,,D*69
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073331.407,3020.7284,N,12006.1697,E,2,03,5.8,-7.0,M,7.0,M,1.3,0000*62
$GPRMC,073331.407,A,3020.7284,N,12006.1697,E,0.00,173.07,141011,,,D*6F
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073332.407,3020.7283,N,12006.1697,E,2,03,5.8,-7.0,M,7.0,M,2.3,0000*65
$GPRMC,073332.407,A,3020.7283,N,12006.1697,E,0.00,173.07,141011,,,D*6B
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073333.407,3020.7284,N,12006.1697,E,2,03,5.8,-7.0,M,7.0,M,3.3,0000*62
$GPGSA,A,2,28,10,13,,,,,,,,,,5.9,5.8,1.0*3A
$GPGSV,3,1,10,10,51,200,34,28,36,182,33,13,18,116,32,17,70,044,*73
$GPGSV,3,2,10,04,56,308,,02,21,271,,20,21,043,,23,20,087,*7A
$GPGSV,3,3,10,12,04,324,,$GPGGA,073456.407,3020.7294,N,12006.1694,E,2,03,5.5,-7.0,M,7.0,M,2.3,0000*68
$GPRMC,073456.407,A,3020.7294,N,12006.1694,E,0.00,173.07,141011,,,D*6B
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073457.407,3020.7296,N,12006.1694,E,2,03,5.5,-7.0,M,7.0,M,1.3,0000*68
$GPRMC,073457.407,A,3020.7296,N,12006.1694,E,0.00,173.07,141011,,,D*68
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073458.407,3020.7295,N,12006.1694,E,2,03,5.5,-7.0,M,7.0,M,2.3,0000*67
$GPGSA,A,2,28,10,13,,,,,,,,,,5.5,5.5,1.0*3B
$GPGSV,3,1,10,10,51,200,34,28,36,182,32,13,18,116,31,17,70,044,*71
$GPGSV,3,2,10,04,56,308,,02,21,271,,20,21,043,,23,20,087,*7A
$GPGSV,3,3,10,12,04,324,,42,48,144,28*7B
$GPRMC,073458.407,A,3020.7295,N,12006.1694,E,0.00,173.07,141011,,,D*64
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073459.407,3020.7295,N,12006.1694,E,2,03,5.5,-7.0,M,7.0,M,3.3,0000*67
$GPRMC,073459.407,A,3020.7295,N,12006.1694,E,0.00,173.07,141011,,,D*65
$GPVTG,173.07,T,,M,0.00,N,0.0,K,N*00
$GPGGA,073500.407,3020.7294,N,12006.1

zjwzcc 发表于 2011-10-14 16:34:46

回复【1楼】d_xin晚风
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sim卡放天线旁边有很大影响么??

另外我看很多设计说天线要先做阻抗匹配才能用,这个具体是怎么理解??

luok 发表于 2011-10-14 16:38:54

回复【3楼】zjwzcc
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就是天线到GPS芯片之间的走线要做好阻抗匹配,不然信号衰减严重,好像是50欧吧

hanfeng000 发表于 2011-10-14 16:39:17

用外置天线试试。 用ublox比较好。

zjwzcc 发表于 2011-10-14 16:50:23

回复【4楼】luok
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50欧的阻抗匹配还真不大清楚,要去查查看。。。

zjwzcc 发表于 2011-10-14 16:50:57

回复【5楼】hanfeng000
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没有外置天线,而且这东西设计不让用外置,得内置的=。=

zjwzcc 发表于 2011-10-14 16:55:28

再传张板子的正面图
帮忙分析下是什么原因导致呢,干扰大么


http://cache.amobbs.com/bbs_upload782111/files_46/ourdev_684910OXJXVK.jpg
正面图 (原文件名:jwd.jpg)

zjwzcc 发表于 2011-10-14 17:01:39

天线到gps之间的走线做好阻抗匹配,具体要怎么操作?是要加另外的元器件还是?

Appcat 发表于 2011-10-14 17:13:25

那板子放到完全开阔的地方试试,窗口不好说。还有,如果GPS没有内置LNA,直接用无源天线比较吃亏的。

zjwzcc 发表于 2011-10-14 18:10:00

刚去楼顶测试了下,有时候可以很快定位,有时候就只能获取时间信息,看来应该是天线设计问题,请教大家了

zctc2008 发表于 2011-10-20 11:58:55

你用的是内置天线,做好电路和抗干扰,以及阻抗,然后考虑的就是内置天线与成绩的匹配,如果确定其他都没问题的话,找到供应天线的厂家去调试天线(阻抗,EMI值)

eess 发表于 2011-11-17 17:51:59

如果是第一次搜,10-15分钟搜到4颗貌似已经不差了
旁边楼宇高么,要移到更开阔的地方吧,愚见。
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