Is it really so few? Snapdragon got support for dual frequency in Snapdragon 855 released in 2018. Use the GPSTest app to see if your phone supports it.

https://github.com/barbeau/gpstest

Here are a couple of phones that don't have dual frequency:

- Samsung Galaxy A53 5G (https://www.gsmarena.com/samsung_galaxy_a53_5g-11268.php)

- Samsung Galaxy S10 (https://www.gsmarena.com/samsung_galaxy_s10_5g-9588.php)

- Samsung Galaxy S20 (https://www.gsmarena.com/samsung_galaxy_s20-10081.php)

- Nokia G60 (https://www.gsmarena.com/nokia_g60-11826.php)

- Google Pixel 5 (https://www.gsmarena.com/google_pixel_5-10386.php)

- Sony Xperia 10 IV (https://www.gsmarena.com/sony_xperia_10_iv-11522.php)

- Apple iPhone 13 Pro (https://www.gsmarena.com/apple_iphone_13_pro-11102.php)

If you want to have this feature you have to start looking at the high end models which are of course expensive. Last time I've checked only Chinese brands like Huawei, Xiaomi or Realme seem to offer it at a more affordable price range.

According to this list[0] some Samsung Galaxy S20 does support it, as does the Pixel 5 (and 4 and 6). Google also lists both models as having L5 support[1].

Of course the best way of knowing if your phone supports it is to test it yourself.

[0] https://docs.google.com/spreadsheets/d/1jXtRCoEnnFNWj6_oFlVW...

[1] https://developer.android.com/guide/topics/sensors/gnss.html...

I suspect the main barrier is patents/licensing/product differentiation rather than the actual difficulty of adding one more PLL, mixer and ADC.

Besides, nearly every phone could receive GPS L5 with the radios in the cell modem if they had a suitable firmware update.

iPhones got it just very recently. So at least half of tge market couldn't have it until recently.