Myron Mageswaran, Alex Boyd, and Maggie Ford

This week we worked on:

• Testing the T/R Switch we made last week
• Getting familiar with the GNURadio Software

In order to test the return loss at each port (TX input, TX output, and RX), we used the antenna analyzer to inject a 5 MHz signal into each port of the transducer. Before we could do this, however, we had to calibrate the antenna analyzer using a short circuit load, an open circuit load, and a load with an impedance of 50 Ohms. Once the antenna analyzer was calibrated, we connected the oscilloscope to the TX input, TX output, and RX ports and measured the return loss at each port with the antenna analyzer when the other ports had an open connection and when the other ports had a load with an impedance of 50 Ohms. The data we collected suggests that the return loss is nearly zero except when a 5 MHz signal was injected into the TX output port and the resistive load was connected to the RX port, as well as when a 5 MHz port was injected into the RX port and the resistive load was connected to the TX output port. The test data we collected is depicted below.

We spent the remainder of the class period on Thursday setting up the virtual machine with the GNURadio software and familiarizing ourselves with how to use the software. Depicted below is a picture of the software defined radio that we are interfacing with using the Linux virtual machine.