The type 'T' cannot be used as type parameter 'T' in the generic type or method

I have the following method:

protected T AttachComponent<T>(){
    T gsComponent = gameObject.GetComponent<T>();
    if(gsComponent == null){
        gsComponent = gameObject.AddComponent<T>();
    }
    return gsComponent;
}

On the AddComponent line I am getting the following error:

The type 'T' cannot be used as type parameter 'T' in the generic type or method 'GameObject.AddComponent()'. There is no boxing conversion or type parameter conversion from 'T' to 'UnityEngine.Component'.

I am not sure what I can do to fix this error, why Can I not do this?