Capacitor on GPS - Githubissues

nakujaproject / avionicsN2_JLC_Computer

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Capacitor on GPS #40

Closed rodneyosodo closed 2 years ago

rodneyosodo commented 2 years ago

The capacitor on the GPS should be in series or parallel? Because I am assuming you are doing some sort of impedance matching or?

kimanimichael commented 2 years ago

From the datasheet.

Screenshot from 2022-04-15 11-04-15

rodneyosodo commented 2 years ago

The capacitor around the antenna

kimanimichael commented 2 years ago

From the datasheet. Screenshot from 2022-04-15 15-54-16

rodneyosodo commented 2 years ago

Is it a matching circuit or a filtering circuit?

kimanimichael commented 2 years ago

Should be matching. Issue also discussed here.

rodneyosodo commented 2 years ago

If it is a matching circuit then the cap should be in parallel

kimanimichael commented 2 years ago

The parallel arrangement would help tune the frequency but the datasheet says otherwise.

kimanimichael commented 2 years ago

@georgebangeboss Thoughts on this?

kimanimichael commented 2 years ago

Should be matching. Issue also discussed here.

It's not a matching circuit. I was wrong on this. It is a series band pass filter.

georgebangeboss commented 2 years ago

The capacitor is a DC blocking capacitor The LNA AT2659 datasheet provides sufficient information about the matching circuits. The datasheet is here

Here are photo snippets