MEMO
EECE 380 (Group L2B1)
To: David Michelson, Associate Professor, UBC
From: Evan Huang, Student
Date: February 9th, 2014
Subject: Weekly Review
Dr. Michelson,
During the third week of the spectrum analyzer project we’ve made some progress in implementing and developing the hardware components of our circuit. For the resolution bandwidth filter we’ve researched and built a crystal ladder filter with an expected1.5 kHz band pass, to cut noise and other signals out of our desired signal. Thorough testing and analysis has shown that our crystal ladder filter has a band pass slightly less than 1.5 kHz, which is acceptable. Our group is also implementing a low pass filter with a cutoff frequency of 1.5 kHz. The low pass filter is fairly simple in design; however our group struggled to practically apply the circuit to cut out noise outside of the 1.5 kHz designed signal. We’ve ordered several operational amplifiers of various frequencies above 10 MHz and are awaiting their arrival. The op amps are to be used in building a precision peak detector to minimize the voltage drop between the input and output of the peak detector.
The two group members previously assigned to design the digital portion of our spectrum analyzer are continuing to familiarizing themselves with myDAQ and the LabVIEW software. Specifics, such as input values and functions, are being considered for the LabVIEW program. The members are implementing the ramp function and its relationship with the voltage-controlled oscillator (VCO) and the electronic mixer. Its output would control the sweeping function of the spectrum analyzer. One of the members expressed a concern with the insufficient amount of time to work with the myDAQ equipment. Without being able to use the myDAQ outside of the labs we may not have enough time to properly troubleshoot the complete project in the future.
Our group members have come to build a rapport with one another. We each contribute a certain necessary aspect to the group and the project, sharing both complications and successes. Our goal for the following week is to complete the hardware design and begin troubleshooting with the given test specifications. For the software, our goal is to fully develop the ramp and display functions, and begin troubleshooting with mock input signals.
With Regards,
Evan Huang