scanning receivers
DESCRIPTION
basic principles of a scanning receiversTRANSCRIPT
Scanning receivers
Sagax Communications, Ltd.
Haller u. 11-13. Budapest 1096 Hungary
www.sagax.hu
Tuned center = 20MHz Tuned center = 2980MHz
0MHz 3000MHz
20MHz
20MHz
20MHz
1ms
100ms
10hps/sec FH signal
20MHz
1ms50us
Traditional receiver structure
WB IF BPF NB IF BPF
LO1
LNA MIX1 MIX2 DET
LO2
RF IN
ADC
SPECTRUMESTIMATION
Digital receiver structure
WB IF BPF Digital Signal Processor
LO1
LNA MIX1
RF IN
ADC
SPECTRUMESTIMATION
Search or band scanning
40 80 120 160 200 240 280 320 360 400
A
440 F
440
Random or memory scanning
A
40 80 120 160 200 240 280 320 360 400 F
440
Tuned receiver implementation
40 80 120 160 200 240 280 320 360 400
A
A
440
40 80 120 160 200 240 280 320 360 400
F
F
Analog Receiver tuning
Spectrum estimation
Scanning Bandwidth Scanning Resolution
440
Digital receiver implementation
40 80 120 160 200 240 280 320 360 400
A
A
440
40 80 120 160 200 240 280 320 360 400
F
F
FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT FFTFFT
Analog Receiver tuning
Spectrum estimation
Scanning Bandwidth Scanning Resolution
440
Memory scanning with digital receiver
A
40 80 120 160 200 240 280 320 360 400 F
1. General test setup
Digital Receiver
SPLIT IF
GEN#2
GEN#1 SUM RF
TUNER
DET Oscilloscope
IF
IF OutputRF Input
Device UnderTest (DUT)