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# <a name="Communication Team Meeting Novem"></a> Communication Team Meeting November 19th, 2003

**In attendence:** Timr, Tim, Glenn, Dave, Andrew

## <a name="First step: Sensitivity analysis"></a> First step: Sensitivity analysis, more measurements, vacuum pumps

- Tim does a sensitivity analysis
- Meet at the VNA and:
  - Remeasure the cylindrical patches
  - Squish the antennas and see how that affects the resonance (with thick polyethylene sheet)
  - Maybe try baking an antenna to see if that makes a difference
- Andrew runs the foam in a bell jar to see what happens to the foam at different pressures
- Do a run at NW EMC as soon as we can

## <a name="Second step: Design the antennas"></a> Second step: Design the antennas

- Take our best guess at a new antenna design
- Choose to go for it, or throw this design out the window and start over

## <a name="Third step: Get the v3&#39;s made or"></a> Third step: Get the v3's made or start over

- Make antennas or start over.

## <a name="Other stuff"></a> Other stuff

- Timr brought up feeding with a slot and thus getting rid of those pesky connectors
- Dave brought up circular polarization
- Foam may not be good under pressure changes. If it isn't, then we might need a solid dielectric.

----

## <a name="Follow up"></a> Follow up

### <a name="Tim&#39;s sensitivity analysis"></a> Tim's sensitivity analysis

The frequency shift vs epsilon\_r is about -572 MHz at epsilon\_r = 1.2, meaning to lower the resonant frequency 5MHz requires an epsilon\_r of around 1.209, which is about +0.7%.

The frequency shift vs dielectric gap is about -3.79 MHz/mm, which is quite low. So this should not be an important factor.

On the other hand, the sensitivity vs gap assumes a _constant_ epsilon\_r in the gap. This may not be the case since it would seem the density of the foam, and therefore its dielectric constant is affected by its state of compression. As noted, anything that changes the dielectric coefficient changes the frequency quite a bit.

### <a name="Foam Sucking"></a> Foam Sucking

See [[CommWorkshop21Nov2003]].