There was a time when the measure of a transmitting radio antenna was having it light an incandescent bulb. A step up was a classic SWR/Power meter that showed you forward and reflected power. Over the years, a few other instruments have tried to provide a deeper look into antenna performance. However, the modern champion is the antenna analyzer which is a way of measuring vector impedance.
[Captain Science] did a review of an inexpensive N1201SA analyzer. This device is well under $200 from the usual Chinese sellers. The only thing a bit odd is the frequency range which is 140 MHz to 2700 MHz. For some extra money (about $80 or $100 more) you can drop the low-end frequency to just under 35 MHz.
In addition to the review, you might want to read the manual. The device can measure resistance, reactance, SWR, and S11 (the S parameter for return loss). It also displays the impedance and effective inductance. [Captain Science] thought the interface was easy to use, but he did wish for a numeric keypad.
While you might think this is a great toy for ham radio operators, it would be useful for anyone wanting an antenna in this frequency range. For example, if you are trying to maximize WiFi range or figure out the greatest ever antenna on your drone, this could be for you (as long as you are not on the 5 GHz band).