A University of Calgary Department of Physics and Astronomy
Graduate Course in Radio Astronomy
Characterisation of the Receiver Path
Nicole Kaiser, December 12, 2005
The overall gain of the receiver signal path was characterized using a signal generator as a source and an oscilloscope as a detector. The class divided into pairs, and each pair made their own measurements of the gain of the 1st IF, the 2nd Mixer, the 3rd Mixer, and of the entire receiver path (full system). The components of the receiver path are shown in figure 1. The results of each group were combined together, and the mean values and standard deviations were calculated. Figures 2 to 5 are the results we obtained.
Figure 1: Receiver Chain: from left to right - 3rd Mixer, 2nd Mixer, 1st IF.
Figure 2: Characterization of the 1st IF.
Figure 3: Characterization of the 2nd Mixer.
Figure 4: Characterization of the 3rd Mixer
Figure 5: Characterization of the Full System
After this characterization was done, some modifications were made to the receiver path to help boost the signal from the 21 cm HI line. The overall characterization changed slightly, as shown in figure 6.
