Simultaneous Transmit and Receive Antenna: Analysis of Measurement Accuracy on Performance

The purpose of the Simultaneous Transmit and Receive Antenna project is to design a test circuit that will allow us to use an antenna to both send out and receive a signal at the same time on the same frequency. The test circuit will generate DC voltage levels that we can use to solve for the gain and delay of the transmit interference, so we will then be able to cancel out the unwanted signal from the received signal. With a theoretically perfect setup, the transmitted signal will be able to be completely isolated from the received signal, leaving us with only what we want at the output. In practice, however, this is not the case. There are many variables that will affect the integrity of the DC output of the test signal. As the output voltage level deviates from its theoretical perfect measurement, the precision to which we are able to solve for the gain and delay values decreases. The focus of this study is to estimate the effect of using a digital measurement tool to measure the output of the test circuit. Assuming a voltmeter with 1 volt full range, simulations were run using measurements stored at different bit resolutions, from 8-bit storage up to 16-bit storage. Since the physical hardware for the Simultaneous Transmit and Receive test circuit is not currently available, these tests were performed with an edited version of the Matlab simulation created for the Senior Design project. The simulation was run 2000 times over each bit resolution to get a wide range of generated values, then the error from each run was analyzed to come to a conclusion on the effect of the digital measurement on the design. The results of these simulations as well as further details of the project and testing are described inside this document.