My Take
One of my biggest challenges when I am working with wireless communication projects is to reach the expected range. If you have the same problem, I recommend you read more about dBm and dBi and RSSI. Above is the picture from an antenna I wanted to use for my LoRa Tracker.
The Lora operates at 915MHz and as you can clearly see the antenna is optimized for a lower frequency. What I had to do was to solder some wire on top of the antenna and then cut them to get to the exact 915.
I found the PS100 (some call it VNA) a good entry point for beginners and I was able to optimize many of antennas that were far beyond acceptable level.