https://github.com/brainstorm/915mhz
915Mhz matching jig experiments
https://github.com/brainstorm/915mhz
915mhz kicad rf
Last synced: about 2 months ago
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915Mhz matching jig experiments
- Host: GitHub
- URL: https://github.com/brainstorm/915mhz
- Owner: brainstorm
- Created: 2018-07-22T13:02:30.000Z (almost 7 years ago)
- Default Branch: master
- Last Pushed: 2019-01-04T06:51:07.000Z (over 6 years ago)
- Last Synced: 2025-02-08T15:25:12.514Z (3 months ago)
- Topics: 915mhz, kicad, rf
- Language: Shell
- Size: 1020 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# 915Mhz RF filter breakout boards
This is an experiment with a 915Mhz LoRa module and SAW filters as a substitute for discrete components. The original *raison d'être* of this repository is my personal outrage after seeing the following **$100 evaluation board** for the [PE4259](https://www.psemi.com/pdf/datasheets/pe4259ds.pdf):
And indeed, [AppliedCarbon from OSHPark also thought so and designed a smaller PCB](https://oshpark.com/shared_projects/2MRloEFC).
Gold tracks and pads, many vias and proper RF engineering, sure, but $100 plus shipping? Let's see how the homemade way works in comparison? On the **`master`** branch of this repository, I'm putting together a board with the RF switch and the SAW filter (will be using a 915 Mhz [sf2098e "low insertion loss" SAW filter](https://wireless.murata.com/RFM/data/sf2098e.pdf), no frills design for now. I might put the vias in place if needed in the future and compare performance/loss and the accompanying [S parameters](https://en.wikipedia.org/wiki/Scattering_parameters).
But since the approach above might not be modular enough for my testing purposes (thanks Chris), I've forked that layout into two branches:
```bash
$ git branch -a
* master
rf_switch_only
saw_filter_only
```
Here's how each of those look like at the moment of writing this, let's play "spot the differences", shall we?:
Now, as with the [Instructables Carvey Board project](https://github.com/brainstorm/carvey_board), I've generated some G-Code (under the **homefab** subdirectory) with [FlatCam](http://flatcam.org/) to carve those board at home, wish me luck with the spectrum analyzers and followup testing!
Alternatively, there's a .zip under homefab, containing the ready-to-send gerbers to i.e Seed Studios or any other PCB manufacturer. Here's the latest iteration of the rf matching board on `master`:
