请教天线参数？

maomao

如何选择天线，那个smith图怎么看？

kachy

<P>找本微波与天线的书看看再说</P><P>如果以前没怎么学过</P><P>建议多看几遍</P>

RFfans

<P>看这篇吧，smith chart基本原理</P><P><a href="http://www.52rd.com/S_txt/2005_8/txt1423.htm" target="_blank" >http://www.52rd.com/S_txt/2005_8/txt1423.htm</A></P>

jensen_g

smith 圆图是基于反射系数极坐标系平面的，最常见的是用来表示阻抗和导纳在该平面的映射，还能把稳定性圆、噪声系数、驻波比、等增益圆在该圆图表示，应用在匹配网络设计、器件及系统参数的验证上，通过它射频系统的许多问题可一一目了然看出来[br]<p align=right><font color=red>+5 RD币</font></p>

kachy

<P>说得不错</P><P>赞一个</P>

dhsdhs

<TABLE cellSpacing=0 cellPadding=2 width="90%" align=center border=1><TR bgColor=#ff9966><TD colSpan=2></TD></TR><TR><TD colSpan=2><FONT face=仿宋_GB2312 color=#0000cc size=3>电性能(Band 1)</FONT></TD></TR><TR><TD width="64%"><DIV align=center><FONT face=仿宋_GB2312 size=3>技术参数</FONT></DIV></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3>性能指标</FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>增益Gain</FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>16<FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>dBi</FONT></FONT></FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>频率范围<FONT face=仿宋_GB2312 size=3>Frequency Range</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3>870 --- 960 <FONT face=仿宋_GB2312 size=3>MHz</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>双极化<FONT face=仿宋_GB2312 size=3>Polarisation Dual</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>Slant ± 45°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>端口隔离度<FONT face=仿宋_GB2312 size=3>Isolation between ports</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>330<FONT face=仿宋_GB2312 size=3> dB</FONT></FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=16><FONT face=仿宋_GB2312 size=3>水平平面<FONT face=仿宋_GB2312 size=3>-3dB 功率角
Horizontal Plane -3dB Power Beamwidth </FONT></FONT></TD><TD width="36%" height=16><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>65°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>垂直<FONT face=仿宋_GB2312 size=3>平</FONT>面<FONT face=仿宋_GB2312 size=3>-3dB <FONT face=仿宋_GB2312 size=3>功率角</FONT>
Vertical Plane -3dB Power Beamwidth
</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>8°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>水平面<FONT face=仿宋_GB2312 size=3>-10dB Power Beamwidth
Horizontal Plane -10dB Power Beamwidth </FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>125°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>阻抗<FONT face=仿宋_GB2312 size=3>Impedance</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>50 <FONT face=仿宋_GB2312 size=3>Ohm</FONT> </FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>回波损耗<FONT face=仿宋_GB2312 size=3>Return Loss 870-960 MHz</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>316 <FONT face=仿宋_GB2312 size=3>dB</FONT> </FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>前后比<FONT face=仿宋_GB2312 size=3>Front to Back Ratio</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>325 <FONT face=仿宋_GB2312 size=3>dB</FONT> </FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>端口最大输入功率<FONT face=仿宋_GB2312 size=3>Max Input Power per port</FONT></FONT></TD><TD width="36%"><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>150 <FONT face=仿宋_GB2312 size=3>W</FONT> </FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>Electrical Downtilt</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>1 to 10°</FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>Downtilt Setting Accuracy</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>± 0.5°</FONT></FONT></DIV></TD></TR><TR><TD colSpan=2 height=21><DIV align=left><FONT face=仿宋_GB2312 size=3></FONT><FONT face=仿宋_GB2312 color=#0000cc size=3>电性能(Band 2)</FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>增益Gain</FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>16<FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>dBi</FONT></FONT></FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>频率范围<FONT face=仿宋_GB2312 size=3>Frequency Range</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>1710-1880 MHz </FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>双极化<FONT face=仿宋_GB2312 size=3>Polarisation Dual</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>Slant ± 45°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>端口隔离度<FONT face=仿宋_GB2312 size=3>Isolation between ports</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>330 dB </FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=16><FONT face=仿宋_GB2312 size=3>水平平面<FONT face=仿宋_GB2312 size=3>-3dB 功率角
Horizontal Plane -3dB Power Beamwidth </FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>65°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>垂直<FONT face=仿宋_GB2312 size=3>平</FONT>面<FONT face=仿宋_GB2312 size=3>-3dB <FONT face=仿宋_GB2312 size=3>功率角</FONT>
Vertical Plane -3dB Power Beamwidth
</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>8°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>水平面<FONT face=仿宋_GB2312 size=3>-10dB Power Beamwidth
Horizontal Plane -10dB Power Beamwidth </FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>120°</FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>阻抗<FONT face=仿宋_GB2312 size=3>Impedance</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>50 Ohm </FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>回波损耗<FONT face=仿宋_GB2312 size=3>Return Loss 870-960 MHz</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>314 dB </FONT></FONT></DIV></TD></TR><TR><TD width="64%"><FONT face=仿宋_GB2312 size=3>前后比<FONT face=仿宋_GB2312 size=3>Front to Back Ratio</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>325</FONT> <FONT face=仿宋_GB2312 size=3>dB </FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=29><FONT face=仿宋_GB2312 size=3>端口最大输入功率<FONT face=仿宋_GB2312 size=3>Max Input Power per port</FONT></FONT></TD><TD width="36%" height=29><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>125 W </FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>电调<FONT face=仿宋_GB2312>下倾角度</FONT><FONT face=仿宋_GB2312 size=3>Electrical Downtilt</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>1 to 10°</FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>电调<FONT face=仿宋_GB2312>下倾角度</FONT>精确度<FONT face=仿宋_GB2312 size=3>Downtilt Setting Accuracy</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>± 0.5°</FONT></FONT></DIV></TD></TR><TR><TD colSpan=2 height=21><DIV align=left><FONT face=仿宋_GB2312 size=3></FONT><FONT face=仿宋_GB2312 size=3><FONT color=#0000cc>电性能(一般)</FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>连接器类型<FONT face=仿宋_GB2312 size=3>Connectors Type</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>7/16 DIN, N optional </FONT></FONT></DIV></TD></TR><TR><TD colSpan=2 height=21><DIV align=left><FONT face=仿宋_GB2312 size=3></FONT><FONT face=仿宋_GB2312 size=3><FONT color=#0000cc>机械性能</FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>高度<FONT face=仿宋_GB2312 size=3>Height</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>2258 mm </FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>宽度<FONT face=仿宋_GB2312 size=3>Width</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>400 mm </FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>深度<FONT face=仿宋_GB2312 size=3>Depth</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>139 mm </FONT></FONT></DIV></TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>额定风速度<FONT face=仿宋_GB2312 size=3>Rated Wind Speed</FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>200 km/hr </FONT></FONT></DIV></TD></TR><TR><TD colSpan=2 height=12><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>Thrust at Wind Speed of</FONT></FONT> <FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>160 km/hr kgf 175</FONT></FONT> </TD></TR><TR><TD width="64%" height=21><FONT face=仿宋_GB2312 size=3>重量(除安装机架)
<FONT face=仿宋_GB2312 size=3>Weight(excluding mounting brackets) </FONT></FONT></TD><TD width="36%" height=21><DIV align=center><FONT face=仿宋_GB2312 size=3><FONT face=仿宋_GB2312 size=3>TBOutline Drawing No MK105
kg </FONT></FONT></DIV></TD></TR></TABLE>[br]<p align=right><font color=red>+3 RD币</font></p>

anotherguy

<P>楼上列的是基站天线基本指标</P><P>目前终端应用中还比较关心的指标是：TRP（总辐射功率），EIRP（等效全向辐射功率），SAR等</P><P>当然，实际中还有一个非常重要的指标：price   </P>[em01][br]<p align=right><font color=red>+5 RD币</font></p>

RF110

<P>昏，我要手机里天线性能指标</P>