Team may00-04 Fazal Baloch, EE Yew-Kwong Soo, EE Wee-Liat Tay, EE Chris Van Oosbree, CprE Walter Wedan, EE Abstract The purpose of this project is to develop a PC based spectrum analyzer. Specifically, this analyzer will be used by Teradyne to verify it’s own line of testing products, which in turn are used in the testing and verification of semiconductors used in cell phones, DSP devices, converters, and micro-controllers. Advisors: Dr. Julie Dickerson Dr. William Black Client: Teradyne, North Reading, MA Introduction General Background - Spectrum analyzers can be used to calculate the noise characteristics of input signals. A signal’s frequency spectrum is often displayed, much like the one shown here. Technical Problem - The analyzer will be implemented using a PC, software, and a data acquisition card (DAQ). Software will be written to analyze the noise characteristics of signals captured by the DAQ. Operating Environment - The analyzer will operate in a typical test lab environment. Normal humidity and temperature are expected. Intended Users & Uses - This spectrum analyzer will be used by Teradyne to verify their own line of testing products. Assumptions & Limitations - It is assumed that the highest fundamental frequency that will be measured is 10 MHZ, with a 3rd harmonic at 30 MHz. Design Requirements Design Objectives - The PC based spectrum analyzer will be easy to use and accurate. Functional Requirements - A 10 MHz signal and it’s first two harmonics will be captured and analyzed. Noise measurements will be made down to -135 dB below the fundamental. Design Constraints - Visual Basic must be used to develop the software. Signals with a frequency higher than the capture rate of the DAQ can not be analyzed. Measurable Milestones - The team must become familiar with Visual Basic. Signal analysis routines must be written, or obtained. The digitizer card must accurately capture a known input signal. This signal will pass through a notch filter to bring the fundamental down to the dynamic range of the second harmonic to increase the resolution of the harmonic amplitude measurements. Input Signal A sinusoidal signal with noise and distortion 63 dB below the fundamental. The analyzer PC has dual 600 MHz Pentium III processors and 1 gigabyte of RAM. Since the filters are not ideal, a procedure will be carried out in software to find the frequency response of the filter with N frequency increments. The digitized signal is broken into a series of sample arrays with N elements and a DFT will be performed on each array. The array of N elements representing the DFT is divided by the frequency response array, element by element, to get the spectrum of the unfiltered signal. This spectrum is displayed on a plot much like the one seen above. End-Product Description The PC based spectrum analyzer accurately verifies test equipment used in testing and verification of semiconductors. It offers the ability to sample input signals at a very fast rate. The analyzer has the ability to detect minute amounts of noise and harmonic distortion in a signal, and storing the acquired data. To meet any future demands, this product is easily upgraded due to its software-based design. The PC utilizes a 12-bit Data Acquisition Card (DAQ) that samples at a rate of 65 Mega- samples per second to digitize the signal under analysis. Technical Approach