A wideband antenna is not what you're looking for – you really don't care about anything between 900 and 1500 MHz, or between 1600 and 2400 MHz.
Wideband antennas are inherently hard to make, and even harder, even impossible, to make uniformly good across their whole range.
What you much likely will rather want is a multi-band antenna. For example, I'd assume that you can get 2400 + 900 MHz antennas commercially, as that is, due to ISM bands, a rather common combination.
Something feels off about your presumption that you'll build a GNSS transceiver; you definitely want a receiver, but I doubt you'll send data to a GNSS satellite ;)
So, honestly, what small multi-band devices like smart phones do is having separate PIFA antenna for the completely separate GPS receiver (that luckily fall far above the 800/900 MHz GSM frequencies and far below UMTS at 1800 MHz), and then typically have some combined multi-band antenna for the rest, which is integrated into the mechanical design of the device.
Simple multi-band antennas I've seen look like connected dipoles for different wavelengths – but not really, the "branches" tend to be slightly offset (not periodically offset like in logper wideband antennas) and not quite exactly as long as they should be. My best guess is that someone started with an antenna that is just multiple dipoles for these frequencies connected to the same feedline, and then just simulated that, got the frequency response, and started randomly change lengths and positions until things worked out.