The Charge of the God can also be used as an invocation.
Here are a few more!

Ancient God of forest depths
Master of beasts and Sun
Here where the world is hushed and sleeps
Now that the day is done
I call You in the ancient way
Here is my circle round
Asking that You will hear me pray
And send Your sun force down.


Blazing God
You who are the King of the Gods
Lord of the Sun
Master of all that is wild and free
Father of woman and man
Lover of the Moon Goddess
And protector of all the Wicca
Descend, I pray,
With your solar ray of power
Upon my circle here.


Great God, Horned one of forests and wild places
Lord of the Sun, bringer of warmth and light
You who runs with the swift stag, soar with the birds in the sky,
And protector of all the Mother's children
You who are born of the Goddess,
Her lover, and Her son, as are all men,
Be with me now,
As I perform this sacred rite.