Hi, I am using the new WBX board and wanted to know if it needs external
filters for better reception.
Kr
On 02/08/2010 09:31 AM, Kunal Rele wrote:
Hi, I am using the new WBX board and wanted to know if it needs external
filters for better reception.
The WBX has a wide-open front end, so strong signals can cause intermod.
It does have very good dynamic range, so that shouldn’t be a problem
except in the more extreme cases.
The small front end board (the grand-daughterboard or GDB for short) has
a place to put a filter. Mini-circuits has a whole family that fits
that footprint. Populated on the board as it ships is a 2.2 GHz LPF.
Also keep in mind that the transmitter will output harmonics, primarily
the 3rd and 5th. So if you’re transmitting at about 750 MHz or lower,
your third harmonic will also be transmitting.
The main purpose to having the GDB system is for people to be able to
have different frontends for different purposes. For example, you could
make one with filters for all the mobile phone bands, or you could make
one with filters for the amateur bands, or TV bands, etc. You can also
build in a higher power amplifier there if you like. It should be
simple to do that if you look at the schematics.
Matt