Doppler Simulator for 10 GHz Doppler Radar Presented by Ngeok Kuan Wai 2252462 Supervised by Prof. Dr.-Ing. K. Solbach
Outline Motivation Doppler Radar and Doppler Simulator Phase shifter Other Electronic Circuits/ Devices Optimization of the Design Final Result
Motivation To design a Doppler simulator To design electronic circuits which enable phase shifter to produce linear phase shift and constant insertion loss. generate ramp voltage with adjustable sweeping frequencies.
Doppler Radar and Doppler Simulator Doppler Effect: Detection of frequency change due to relative motion between source and observer When source moves towards observer, higher frequency is detected, and vice versa. Direction of moving
Doppler Radar and Doppler Simulator Doppler Radar: Make use of Doppler Effect to measure the speed of detected objects. Doppler frequency, f d = 2 v f r / c o Rate of phase shift is velocity dependent
Doppler Radar and Doppler Simulator Question: Is Doppler radar possible to detect movement when there is only a stationary object? Answer: Yes, only if the stationary object generates Doppler wave (continuous phase-shifted wave). Doppler simulator!!
Phase Shifter A 2-port device which is able to provide change in the phase of RF signal. Control voltage
Phase Shifter ( o ) (db) 400-5 300-8 200 100-11 Phase Magnitude 0 0 5 10 15 (V) -14
Other Electronic Circuits/ Devices 1. Voltage-controlled amplifier: To compensate the variation in insertion loss of the phase shifter Amplification depends on the control voltage Input port V D Output port V G
Other Electronic Circuits/ Devices 2. Level shifter: To shift control voltage to the required level. Supply Output Input
Other Electronic Circuits/ Devices 3. Equalizer: To transform control voltages to particular voltage function Supply and Input Output
Other Electronic Circuits/ Devices 4. Ramp generator To generate ramp voltage waveform with adjustable sweeping frequencies Voltage Supply Knob Output 1 Output 2
Other Electronic Circuits/ Devices 4. Ramp generator Phase shift ( o ) Phase shift detected by Doppler radar 1080 720 360 Phase shift produced by phase shifter 0 Time
Optimization of the Design S 21 Phase Shifter Amplifier Level Shifter? Equalizer 1? Equalizer 2 0V 15V
Optimization of the Design S 21 Phase Shifter Amplifier Level Shifter Equalizer 1 Equalizer 2 0V 15V
Optimization of the Design ( o ) 400 Phase shift vs. Voltage 300 200 Measured Phase Required Phase 100 0 0 3 6 9 12 15 (V) Zoom in
Optimization of the Design ( o ) Transformation of control voltage 40 35 30 25 24 o 20 15 10 5 0 12 o 0 0,5 0.6 1 1.2 1,5 Measured phase Required phase (V)
Optimization of the Design (V) 15 Transformation curve 12 9 6 3 0 0 3 6 9 12 15 (V)
Optimization of the Design (V) 15 Transformation curve of Equalizer 1 12 9 6 3 0 0 3 6 9 12 15 (V)
Optimization of the Design S 21 Phase Shifter Amplifier Level Shifter Equalizer 1 Equalizer 2 0V 15V
Optimization of the Design ( o ) (db) 400 Magnitude Phase -4 300-6 200-8 100-10 0 0 3 6 9 12 15 (V) -12
(db) 8 Optimization of the Design Resultant magnitude (db) -4 6 Magnitude of phase shifter -6 4-8 2 0 Required magnitude of amplifier 0 3 6 9 12 15 (V) -10-12
Optimization of the Design (db) 8 6 Magnitude characteristic of amplifier 4 2 0 Required magnitude of amplifier 0 3 6 9 12 15 (V)
Optimization of the Design (V) 15 Transformation curve of Equalizer 2 12 9 6 3 0 0 3 6 9 12 15 (V)
Optimization of the Design S 21 Phase Shifter Amplifier Level Shifter Equalizer 1 Equalizer 2 0V 15V
Optimization of the Design (db) -4-6 ( o ) 400 300 15 o -8-10 200 100 magnitude phase -12 Readjust Equalizer 1 for phase correction!! 0 0 3 6 9 12 15 (V)
Optimization of the Design (V) 15 Transformation curve of Equalizer 1 12 9 6 3 0 0 3 6 9 12 15 (V)
Optimization of the Design (db) -4 ( o ) 400 σ = 0.076 db -6 300-8 -10 σ = 1.46 o 200 100 magnitude phase -12 0 3 6 9 12 15 0
Optimization of the Design S 21 Phase Shifter Amplifier Level Shifter Equalizer 1 Equalizer 2 Ramp Generator
Optimization of the Design Ramp Generator Equalizer 1 Input Port Phase Shifter Voltage -controlled Amplifier Output Port Knob Equalizer 2 Level Shifter
Final Result Measurement results at CW mode at simulation velocity 1 km/h
Final Result
Conclusion Before: 400 300 200 100-5 -8-11 Phase Magnitude 0 0 5 10 15-14 After: 400 300 200 100-5 -8-11 Phase Magnitude 0 0 5 10 15-14
Conclusion +18V -18V 1 km/h 100 km/h
Thank You for Your attention!