User Manual

- 55 -
Appendix D - Inside WR-G303
Technically minded users may like to explore the WiNRADiO G303 Receiver
and experiment with some of the innovative concepts of Software Defined
Radio.
The WiNRADiO G303 Receiver is the world’s first commercially available
Software Defined Radio, where the Demodulator function is fully performed
in software running on a standard PC. The G303i model is also the world’s
first shortwave radio on a PCI card, while the G303e model is the first PC-
based shortwave radio with the USB interface. The potential for
experimentation is therefore substantial. This receiver and its software have
been indeed designed to promote and encourage such experimentation.
The WiNRADiO G303 receiver represents only one half of the entire radio.
The other half is your PC.
The receiver hardware contains the following functional blocks:
The incoming signal from the antenna (in the 9 kHz to 30 MHz range) is
filtered and amplified, then fed into a mixer. Here it is mixed with the first LO
(local oscillator), which is performed by a DDS (Direct Digital Synthesizer),
with a PLL (Phase Locked Loop). The resulting 45 MHz intermediate
frequency is filtered using a 4-pole 45 MHz crystal filter with an IF bandwidth
of 15 kHz, and then amplified.