[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] Analog Devices RF RX/TX subsystems for Spartan-3A
Re: [Discuss-gnuradio] Analog Devices RF RX/TX subsystems for Spartan-3AN FPGA
Fri, 18 Jun 2010 00:26:10 -0400
Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:126.96.36.199) Gecko/20100317 Thunderbird/3.0.4
An RF Front-end can take many forms, depending upon the application. For
use with the USRP or similar hardware, a direct-conversion approach is
probably adequate. This type of front-end typically consists of low
noise amplifier (LNA), mixer, and perhaps a baseband/IF amplifier or
automatic-gain control (AGC) amplifier. Determing the requirements for
amplifier gains will be based on mixer conversion loss and the receiver
Designing the RF front-end requires knowledge of RF and microwave
circuits and perhaps impedance matching skills and amplifier design
depending upon how low-level you want to get into the design process.
This is not a simple task. That said, however, coaxial components are
available from manufacturers such as Mini-circuits that are relatively
easy to work with provided you are working relatively low frequency (~7
GHz or less).
Also, it is worth pointing out that the ADC and DACs that you choose are
part of the analog front-end, and they have an associated noise figure
and power requirements. As such, if you are looking to design an RF
front-end, choosing an ADC/DAC might not be the way to go.
On 6/17/2010 12:58 PM, Elvis Dowson wrote:
I would like to design a custom board based on the Spartan-3AN FPGA,
based on the Spartan-3AN FPGA Starter Kit, but would like to build my own RF
If I look at the AD9874 IF-to-Bits RX subsystem component
it contains an ADC and a whole bunch of other stuff.
Could someone help me by pointing out what other components or parts I should
be looking at to build the RF receiver front-end to start with, assuming that I
am going to learn from the USRP2 design, and the fact that it already has the
Spartan-3AN FPGA, and I'm going to build my own RF front-end?