Apache Labs ANDROMEDA ANAN-7000DLE MKII - 1.2 Architecture

ANDROMEDAManual Page8of56
1.2 Architecture
FPGA
THETISonPC
RF
Filters
Variable
Att en‐
uator
Ant,
T/R
Switch
A‐D
Conver‐
ter
VFO
Tune
Band
Digital
Down‐
Con vert
Low
Pass
Filters
Linear
Amplifier
D‐A
Conver‐
ter
VFO
Tune
Band
Digital
Up‐
Con vert
VFO
Tune
Digital
Down‐
Con vert
2Channel
Receiver
DSP
TXAudio
DSP
Keyer
Puresignal
Linear‐
isation
Ether net
Userinterface
Fro ntpa nel
1
2
3
RF
Filters
Variable
Att en‐
uator
A‐D
Conver‐
ter
VFO
Tune
Band
Digital
Down‐
Con vert
RX2
ant
Audio
Cod ec
Ether net

1. Yourradiohardwareprovidesatransmit/receivepath.TherearetwofullyseparateRXpaths
eachwithitsownsignalconditioning,digitisingandprocessing.
2. Receivedsignalsarefiltered,attenuatedthendigitisedusingtwohighperformance
analogue‐to‐digitalconverter.TheA‐DconverterscoverthewholeHFband.Digital
processingintheFieldProgrammableGateArray(FPGA)convertsapartof theHFbandto
zerocentrefrequency,andtransfersthedatatothePCviaEthernet.Thebandwidth
providedcanbesele cted,butisusuallyintherange48KHz–1.536MHz.
3. ThePCrunstheTHETISprogram.THETIS
hastwohalves:auserinterface,andPCbased
signalprocessing.
4. THETISconnectstothereceiverdatastreamsandprovidesfurthersignalprocessingto
reducenoise,toselectthesignalsofinterestanddemodulatethem.Itsuserinterface
providesaviewofthebandactivityinthedownconvertedsignal
isshown,andcontrolsto
tunetotherequiredsignalanddemodulateitsuccessfully.
5. Receivedaudioisroutedtotheinternalspeakers.AdditionalPCconnectedspeakersarealso
possible.
6. Ontransmit,THETISprovidestheinitialsignalprocessingtooptimi sethetransmitsignal.
Audioprocessingisavailabletoenhancea
voicesignal.ACWkeyerisprovided.Sampled
dataissenttotheradiohardwareviaEthernet.
7. Theradiohardwareupconverts theTXsignaltotherequiredfrequency,setsitssignallevel,
amplifiesandfiltersit.Amplifierlinearizationisavailable:asampleofthesignalfromthe
linearamplifier
isdownconvertedbackthroughthereceiver,andcomparedwiththe
“intended”TXsignal.ThedifferenceisprocessedbyTHETIStoapplypre‐distortionsothat
thefinaloutputfromthelinearamplifierhasapproximately20dBlowerspurioussignal
contentthata“normal”HFtransmission.