Questions in Coaxial Cable
Would like to know which kind of coaxial cable in the 'RG' family for eg. RG58A/U be able to support at a working frequency of 1.575GHz and above. Would be appreciate if anyone could provide with the info. Thank you.
Keigo
hi Keigo
see this site
http://www.microwaves101.com/encyclopedia/coax.cfm
Coaxial Cable Spec:
http://www.rfcafe.com/references/ele...coax_chart.htm
Cutoff Frequency Calculations:
www.rfcafe.com/references/electrical/coax.htm
You may not want to use the RG series. This was the US military designator for "radio guides" from around 1940. They had solid dielectric. Around 1970 improved cables with foam dielectric were introduced. These had larger diameter inner conductors and lower attenuation.
Since then different even lower attenuation cables have been introduced, commonly with four number designators.
It looks like you are using an antenna separated from the receiver for a GPS receiver. You can get around the cable attenuation problem by having a RF amplifier at the antenna end of the cable. The gain should be 6 dB or more than the cable attenuation.
http://www.cel.com/pdf/appnotes/an10...1.575%20GHz%22 is an example of such an amplifier.
Dear,
This two cables are excellent & their sizes are near to RG58.
RG223
RG142
Good Luck!
maximum frequency depend on dimension and density of the braid.
As diameter is large as cut-off freq. is small, as attenuation is low, as power handling is high.
As braid is sparse as Fmax is low
For example, a RG58A/U or 223 or 213 have cutoff very far, but the well shielded, double braid RG223 is not shielded enough for Freq>5 and it radiate for F>5GHz
RG58 has 3 dB/m insertion loss @ 2 GHz