According to page 5 of the HMC903 datasheet – Vgg1 and Vgg2 should be left open if you want normal, self-biased operation. If you want to reduce current drain, you connect external capacitors.
Then looking at page 7 of the datasheet, I am not so sure. It shows Vgg1 and Vgg2 connected to capacitors for the “Application Circuit - Standard (Self-Biased) Operation”.
Does connecting Vgg1 and Vgg2 through 100pF capacitors create an open circuit? Or is it just an error in the datasheet?