Can you use other lengths than 1/2 wavelength?
You will need to find a way to tune them as they will not naturally provide a low SWR, and most of them will not be resonant. If you are looking for broadside gain you can go up to about 5/8 wavelengths per side, which is about 1.25 total wavelengths. Most people call the 1/2 wavelength variant dipoles, and the non-1/2 wavelength viariants doublets. And more specifically, if it is one wavelength long, that is sometimes referred to as a Double Zepp, and 1.25 wavelengths it is referred as an Extended Double Zepp (or EDZ for short). The EDZ can be tuned to a reasonable impedance with a length of 450 ohm window line and is at or near the longest length of straight wire you can have and still have broadside gain.