Zeraph

Anyone a vocalist? I haven't been singing too long (bout a year), but I know the basics. One thing I just can't get right is vibrato! I can sort of force it, and very occasionally I'll do it naturally if my voice is really soft. Any explanations I look up (or even talk to really good singers in real life) just doesn't cut it for my way of understanding things. I need like, physiological insight. Although if you have your own way of explaining it feel free. Anyone have, or know of, a good explanation to produce vibrato with one's voice?

Thanks