DATE:        February 24, 2014

TO:    Dave Michelson, Ph.D, P.Eng.

FROM:        Mohammad Amirian, EECE 380 Team L2B2

SUBJECT:     Spectrum Analyzer Project Update – Week of Feb 24.

In the week of reading break, we were able to meet and work on the full spectrum analyzer circuit. Due to a setback with our IF filter, we were put further back in our schedule but still managed to stay ahead of our goal. It was clear that our main focus was to design a fully functioning precision peak that would work when connected with the rest of the circuit.

Many different topologies were implemented and yet there were problems with all of them.  There were issues such as oscillations and no output or very weak output when connected to the rest of the circuit. After many attempts, it became obvious that any more time spent on developing a fully functioning peak detector would only stop us from achieving our other objectives and so it was decided that a regular peak detector would suffice for our purposes.

The rest of the circuit is on par with the requirements set for us. We are looking at another two sessions of lab time to fully meet the requirements and even manage to add some extra functionality. We have also managed to start our report earlier than expected.

For the upcoming week our main priority is to fully implement an amplified signal from the output of the IF filter going into the peak detector. On top of that, we also want to add some extra features to the software component and to reduce noise in our circuits. Another update regarding our progress will be provided next Monday (March 3) morning.

DATE:  February 16, 2014

TO: Dave Michelson, Ph.D, P.Eng.

FROM: Remy Savard, EECE 380 Team L2B2

SUBJECT: Spectrum Analyzer Project Update – Week of Feb 10.

This week we encountered major setbacks on our peak detector and IF filter interface, but are still ahead of schedule. Our week became focused on accurately characterizing the IF filter and peak detector circuits as well as understanding why they did not function when used together. We were partially successful.

We succeeded in characterizing the circuits and fine tuning the IF filter. It now responds with a very narrow passband. Our precision peak detector was not sensitive enough to pick up the pulse passing from the IF filter and the IF filter output may need amplification. We also determined ideal operating power for the IF filter and the precision peak detector.

Attendance was an issue for our team this week and caused significant setbacks. With one team member hospitalized and others missing, our team was only able to push ten man-hours into the project. We are attempting to make up time during our vacation this week.

Our plan for the upcoming week is to develop a precision peak detector in parallel with a basic peak detector and characterize performance with an amplified output from the IF filter. If this is successful, our project will be in a functional form and our work will shift to adding features to software and reducing noise in our circuits. We will provide you with another update on our progress next Monday (Feb. 24) morning.

DATE: 10 February , 2014

TO: Dave Michelson, Ph.D, P.Eng.

FROM: Wayne Huang, EECE 380 Team L2B2

SUBJECT: Project Progress Report for the week of February 3rd

This week we attempted to finish up the design and build of the separate blocks of our system. We had a few setbacks where the output of the blocks were undesired or their behaviour unexpected.

Our precision peak detector was implemented using a lm-6172 op amp. The initial output was not what we expected with the value of components we calculated. The output signal was either very noisy or there was a large amount of loss. We deducted that this was caused by the inherent capacitance of the breadboard, and had to tweak the values through trial and error.

We decided to construct our IF bandpass filter using four crystal oscillators in series, without any capacitors. This gave a desirable frequency response with a very narrow band, so we left it as just the crystals in series. Upon further observation, there was a very steady rise in the response at a much later frequency. We will have to test to see if this will cause problems for our system and have though about using a low pass filter as a solution.

We created a basic display in LabVIEW that shows a signal input into the MyDAC and was able to test it by displaying a waveform from the function generator. We attempted to test if the display would work as intended in our system, but we were unable to functionally connect the blocks of our system together.

In the coming week, our goal is to connect all the blocks of our system together, work out any abnormalities and problems, and have a very basic spectrum analyser working.

DATE:               February 3, 2014

TO:           Dave Michelson, Ph.D, P.Eng.

FROM:           Christopher Dunn, EECE 380 Team L2B2

SUBJECT:        Spectrum Analyzer Project Update Highlighting the Week of Jan. 27

    This past week, we made significant forward progress in the project. You will be pleased to hear that we are currently ahead of schedule and on budget. Our main focus last week was the peak detector, the software, and the development of our mathematical models. Our team is showing good communication and a shared vision for the project, with each member contributing equally and enthusiastically.

    We constructed a basic peak detector and tested it with a function generator up to 3.3MHz, which is the maximum capability of the function generator, but we will have to do further testing with an RF signal. We also constructed a precision peak detector, using an LM6172 op amp, but it does not perform well and may need significant modification.

We programmed and tested a ramp generator, and we successfully read test signals from the MyDAC analog input. We also made a very narrow and effective bandpass filter with the crystals provided, which we will use going forward, and we measured and recorded the losses in each of our RF components.

    This week, we will focus on refining and tuning our circuits and putting it all together. We expect to have a working prototype by the end of the week, and we’ll have another update next Monday.