GPS signals are sufficiently low frequency that a phased array would need to be fairly large. Each antenna in the array would need to be around 5cm and you'd n

GPS signals are sufficiently low frequency that a phased array would need to be fairly large. Each antenna in the array would need to be around 5cm and you'd need quite a few of them on each axis. Totally doable but someone probably decided a dish was easier/cheaper than a big board of antennas or waveguides and associated circuitry. Phased array would be nice to have though, since if the array was large enough you could have multiple beams produced by different parts of the array and cover more/multiple areas.