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Dan Bobyn |
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VHF SDR Transmit Signal Exciter This
project developed an architecture and implemented associated hardware for a
very wide range (two octave) VHF SDR narrowband modulated signal source used
in a narrowband data radio. The
exciter accepts digital signal samples and generates an extremely clean,
medium level (1 Watt) angle modulated carrier at the required RF
frequency. Extremely low off-channel
and wideband noise performance is achieved through the use of a phase locked
tracking filter and a digitally tuned multi-pole passive LC filter prior to
amplifying the signal in a wideband low noise balanced LDMOS amplifier. A DDS provides sub-Hz output carrier
frequency resolution. |
© 2018 Dan Bobyn Engineering Ltd.