JavaScript: Sending quotes in a string to style div elements in the DOM, background-image: url('');

For some reason unknown to me, I can't get single quotes in the url('') when I try to set the style.backgroundImage.

I have a div,

<div id="radarDisplay"></div>

that I want to modify with JavaScript after an event (which is working).

I have a URL string,

var imgURL = "http://ift.tt/1Hk6rE9";

Then I modify the string in JavaScript, escaping quotes where I need them:

var bkgdURL = "url(\'" + imgURL + "\')";

In my JavaScript, upon an event, I call:

document.getElementById("radarDisplay").style.backgroundImage = bkgdURL;

No Image....

Looking at the html in my browser, my single quotes in url('') do not appear. It reads:

<div id="radarDisplay" style="background-image: url(http://ift.tt/1Hk6rE9); background-position: 50% 50%; background-repeat: no-repeat;"></div>

I did a console.log(bkgdURL);, and my return was exactly how it should be: url('http://ift.tt/1Hk6rE9')

I've tried it with ", \', and \".

What am I missing here?