Doubler/Amplifier Building Block for CW-Radar (PDF)

Inhaltsangabe:Abstract:
For the measurement of velocity of, e.g., cars on the street or objects in industrial fabrication scenarios we use microwave radiation from so-called CW-Radar systems. The CW-Radar measures the Doppler-frequency of the microwave radiation: A wave of fixed frequency (Continuous Wave, CW) is radiated through a high-gain antenna onto a moving target where it is reflected and the reflected wave is received by the radar antenna again. The reflected wave exhibits a frequency shift (Doppler-frequency) which is proportional to the radial velocity of the target and proportional to the frequency of the transmitted wave.
This wave has frequency 24GHz, generated in the transmitter and after that there are some of parts. The thesis task is to build one part of a radar system which operates at 24 GHz, namely the building block that takes-in the 12 GHz oscillator signal to double the frequency to 24 GHz and amplify it as a driver signal for the transmit amplifier.
This circuit uses RT/Duroid 5870 substrate with 0.25 mm thickness. The measured resonance frequency occurs at 24 GHz. To reduce the effects and the losses in the high frequency, the spacing between the microstrip lines can be increased, where a thinner RT/Duroid 5870 substrate of 0.25 mm is correspondingly used.
And most of the connectors are tested for 24GHz, and the best way to have high performance and low losses between changing from the coaxial cable to the microstrip, where there the most of the losses in the circuits for very high frequency. And there are a radiation in the space, can be considered also. Inhaltsverzeichnis:INTRODUCTION9
1Continuous-Wave (CW) Radar9
2Microwave elements and simulation tools13
2.1Microstrip13
2.2Analysis Electromagnetic Simulation Tools16
2.3Microstrip radial stub:19
2.4Interdigital Capacitors :21
2.5Test Equipment and Techniques:23
2.5.1Connectors:23
2.5.2Normal connectors(SMA):27
3Doubler Frequency : 29
3.1Balanced Doubler :29
3.2With Nonlinear effects:37
4Amplifier 24 GHz:41
4.1Amplifier Characterization:41
4.1.1Power Gain:41
4.1.2Stability:44
4.2Power Adjustment:47
5The Fabrication and Measurement50
5.1Doubler frequency:50
5.2The 24 GHz Amplifier55
5.3Measurement for all system58
6Conclusions53
Appendix A60
Appendix B63
Appendix C66
Appendix D70
Appendix E72
REFERENCE75 Textprobe:Text Sample:
Chapter 2.5, Test Equipment and Techniques:
An Agilent 8722 network analyzer was used for most of the published [...]