Week 4 Memo

Weekly Objectives

• Complete circuits on breadboard as our PCB design is unable to be fabricated

• Complete final testing

• Sand blast and powder coat the circuit enclosure

• recalculate values for crystal oscillator and amplifier circuits due to the change of oscillator from 8MHz to 12MHz

Challenges

• Our PCB quote came back at an astounding $250, so will not be completed due to budget restrictions. We will try to integrate several other groups PCBs into one sheet but we are not expecting it back in time.

• The 8MHz crystal oscillators are not compatible with our bandwidth spec for the project, we have acquired 112MHz crystals but will require a recalculation of circuitry.

• We seem to have a large amount of feedback coming from our RF mixer, we need to consult the TA or come up with a solution, possibly faulty mixer

Next Week Itinerary

• Complete our report,

• Demo Day is this friday!

Summary

In the fourth week of the second rotation of EECE 380 our custom spectrum analyzer has found a growing set of challenges to overcome. Firstly we were given the incorrect oscillators for our specified bandwidth, this mistake cost us a large amount of time that was required to recalculate several amplifier and crystal ladder circuits. We also are unable to have a PCB fabricated in time for our demonstration. We were notified that it would be unable to be completed in time so we had to cancel to order. We are also experiencing some interference from our mixer, it mat be from the mixer, or from our oscillators, further testing will be required to clean up the signal for demonstration. Other than these challenges the hardware and software have come together, more calibration will be done before the demo, but hopefully everything will come together when it counts.